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PREFACE TO THE SECOND EDITION 
 
 Dentistry up to the last ten years made little or no advance 
 along the Hnes of Health Conservation. For two thousand 
 years dentistry has been devising collectors of filth and spreaders 
 of general disease. The Roman, who strapped loose necrotic 
 teeth to firm teeth with gold bands, defied the laws of health and 
 cleanliness no more than many of our bridge workers of the 
 present day. The dentist of the seventh century, in putting 
 in gold fillings, to all intents and purposes used the same method 
 as that of the soft-gold worker of the twentieth century. 
 
 Dentistry, owing to the teachings of Pasteur, has at last 
 awakened to its great responsibility. Henceforth no appHance, 
 however beautiful externally, will be tolerated unless it can be 
 kept absolutely clean, and no repair of a tooth or root will be 
 countenanced unless it conforms to the standards of scientific 
 mouth hygiene. FilKngs, crowns, and bridges are no longer 
 to be considered mere objects of art for personal adornment 
 or mechanical trituration of food, they must primarily be 
 hygienic. 
 
 Through the elimination of mouth infection, and of much con- 
 sequent systemic disease, dentistry must take a place in the fore- 
 most ranks of preventive medicine. Dentists henceforth must 
 be trained along medical Knes, and any contention that has existed 
 in the past between the physician and dentist must disappear 
 in a common endeavor to free the community at large from the 
 deadly effects of mouth infection. For this disease is now 
 recognized as an almost universal one that every year kills its 
 victims directly or indirectly by the hundreds of thousands, 
 and it is the author's hope that this book will be of some service 
 in its cure and prevention. 
 
12 PREFACE 
 
 The author wishes to express his thanks to Dr. Wm. H. Hoedt 
 for his valuable co-operation in illustrating this work, and he 
 wishes further to acknowledge his obligation to Dr. A. P. Hitch- 
 ens and Dr. Claude P. Brown for their bacteriological specimens 
 and their friendly assistance. The original radiographs from 
 which the reproductions of Chapter X have been made are the 
 masterly work of Dr. Wilhs F. Manges. 
 
 Joseph Head. 
 
 Philadelphia, Pa., 
 January, ig20. 
 
CONTENTS 
 
 CHAPTER I 
 
 PAGE 
 
 Causes and Effects of Mouth Infection 17 
 
 CHAPTER II 
 
 Prevention of Mouth Infection 26 
 
 Mouth Cleansing 26 
 
 Method of Using Floss-silk 31 
 
 Method of Brushing the Teeth 35 
 
 CHAPTER III 
 
 A Study of Tooth Enamel and Saliva 43 
 
 Enamel Softening and Hardening 43 
 
 Force Required in Mastication 54 
 
 Dentifrices and Mouth-washes 5^ 
 
 Destructive Action of Dentifrices 60 
 
 CHAPTER IV 
 
 Treatment of Mouth Infection 65 
 
 General Diagnosis 65 
 
 Violet-ray Treatment 74 
 
 Local Treatment 75 
 
 Tartar Solvent 80 
 
 CHAPTER V 
 
 Vaccines in Treatment of Mouth Infection 85 
 
 Theory of Vaccination 85 
 
 Anaphylaxis 88 
 
 Preparation of Vaccines 9° 
 
 Autogenous and Stock Vaccines 91 
 
 Obtaining Parent Germs for Vaccine 93 
 
 Sensitized Vaccine 98 
 
 Vaccine Dosage i°o 
 
 Vaccines and Anemia 106 
 
 Vaccines and Osteo-arthritis to6 
 
 13 
 
14 CONTENTS 
 
 CHAPTER VI 
 
 PAGE 
 
 Treatment of Root Canals 109 
 
 Alveolar Abscess 109 
 
 Local Anesthesia no 
 
 Gum Infiltration 114 
 
 Nerve-blocking 114 
 
 Pressure Anesthesia 117 
 
 Removal of Dental Pulp 1 20 
 
 Tooth Nutrition by Peridental Membrane 121 
 
 Root Canal Preparation 122 
 
 Sterilization and Root Canal Filhng. 124 
 
 Calahan Method 126 
 
 Emetin 128 
 
 Canal Variations 128 
 
 Bleaching 133 
 
 Root Amputation and *-Ray Diagnosis 137 
 
 Root Excision 142 
 
 CHAPTER VII 
 
 FiLUNGS 150 
 
 Operative Efficiency 150 
 
 Old Hammered Filling 151 
 
 Porcelain Inlays 154 
 
 Porcelain Strength 155 
 
 Porcelain Inlay Matrix 161 
 
 Construction of Porcelain Inlay 162 
 
 Color Selection 170 
 
 Making and Baking the Filling 174 
 
 Inserting the Inlay 176 
 
 Gold Inlay 179 
 
 Plastic Fillings 184 
 
 Amalgam 185 
 
 Repair of Broken Roots 188 
 
 Gutta-percha Fillings 192 
 
 CHAPTER VIII 
 
 Children's Teeth 195 
 
 Gum Lancing 195 
 
 Care of Children's Teeth and Gums 197 
 
 Exposed Pulp in Temporary Teeth 203 
 
 Fractured Teeth 204 
 
 Orthodontia for the General Practitioner of Dentistry 207 
 
 Extirpation of the Frenum 239 
 
 Impaction of Teeth 242 
 
 Malnutrition 252 
 
CONTENTS 1$ 
 
 CHAPTER IX 
 
 PACE 
 
 Crowns 258 
 
 Pin Crown 260 
 
 Amalgam Crown with Porcelain Facing 267 
 
 Inlay Crowns 268 
 
 Band Crown 272 
 
 CHAPTER X 
 
 Replacing of Lost Teeth 282 
 
 The Attached Bridge 282 
 
 Removable Appliances 290 
 
 Divergent Abutments 292 
 
 Double Clasp Bridge 298 
 
 All-Gold and Porcelain Fixture ^ 303 
 
 CHAPTER XI 
 
 Experiments Concerning Strength, Solubility, and Adhesiveness of 
 
 Various Cements 3°? 
 
 Silicious Cements 3°7 
 
 Phosphate of Zinc Cements 309 
 
 Tests on Cement Line 31° 
 
 Adhesion of Cement 320 
 
 Cement as Inlay Bond 327 
 
 Solubihty of Cement Line 327 
 
 CHAPTER XII 
 
 Study of Roots and Gums by Means of x-Ray 335 
 
 Interpretation of Plates 337 
 
 Index 377 
 
MODERN DENTISTRY 
 
 CHAPTER I 
 
 CAUSES AND EFFECTS OF MOUTH INFECTION 
 
 The term mouth infection means a condition where disease- 
 bearing germs have estabhshed themselves within the tissues 
 of the mouth, the vital resisting force of these tissues having 
 been temporarily or permanently lowered by systemic disease or 
 some depressing local condition. 
 
 Mouth infection is generally associated with red, swollen 
 gums, with or without the presence of exuding pus, and teeth 
 sensitive to heat, cold, or pressure. In ninety-nine cases out of 
 a hundred the teeth and the gums are the primary seat of the 
 disease, but occasionally it is confined to the cheeks, palate, or 
 lips in the form of superficial self-healing ulcers, syphilitic sores, 
 or slowly progressive areas of inflammation that sooner or later 
 mean cancer. Any persistent fissure or inflammatory hardening 
 of the cheek or lips has so long been known to threaten pro- 
 longed sickness and death that the incipient mahgnant forms of 
 mouth infection generally receive prompt attention and treatment. 
 All abnormal growths in the mouth may be malignant, and on 
 their first appearance should be cut out for examination and 
 diagnosis. 
 
 This book, however, will deal with infections of the gums and 
 teeth, infections that have been complacently endured in chronic 
 form ever since man came upon this globe. For just as the ticks 
 and fleas of India can convey the death-dealing plague from one 
 person to another, so these patiently borne gum and tooth in- 
 fections are now known to originate a long list of fatal diseases, 
 
 2 17 
 
1 8 MODEEN DENTISTRY 
 
 among which are found valvular heart disease, anemia, arthritis 
 deformans, rheumatism, and nervous derangements without end. 
 
 No doubt the first of the cave-dwellers who strove to free 
 himself from vermin was called a finicky dandy. No doubt he 
 was warned by the old men of the tribe that he was endangering 
 his health and even Kfe, and that if he made his body unaccus- 
 tomed to vermin, when he did become infested, the tissues would 
 have lost their defensive power against them. In the same way 
 we have modern cave-men among us who sneer at excessive 
 mouth cleansing as an absurd fad, some even claiming that 
 there are germs in the mouth that have a benign influence for 
 health. In answer to these cave-men, whose real reason is 
 laziness, not science, it must be pointed out that a germ, like a 
 man, cannot escape being judged by the company it keeps, 
 and that when the machine-guns are leveled against a mob the 
 innocent passer-by performs a patriotic duty in accepting 
 death that the streets may be cleared and law and order re- 
 stored. 
 
 Therefore, in spite of the fact that some of the numerous 
 germs that lurk within the mouth may have beneficial possi- 
 bihties, this vague chance must give way before the certain 
 knowledge that the germs of pneumonia, influenza, diphtheria, 
 and catarrh, with a host of other disease-forming germs, are 
 practically always present in every mouth. These germs in a 
 healthy mouth may be harmless, but the moment they succeed 
 in obtaining entrance to an area of weakened or inflamed tissue 
 they shortly become forerunners of their respective diseases, 
 both local and systemic. Healthy blood, in conjunction with 
 healthy tissue-cells, is fully capable of restraining the growth of a 
 limited number of disease germs. Even the dreaded tubercle 
 bacillus can be controlled and destroyed by healthy tissues if the 
 germs appear only in very Kmited numbers. Therefore, it is of 
 the utmost importance that the blood and the tissues shall be 
 kept at their normal power to control these germs that are ever- 
 present in the mouth; and if these germs do gain an entrance to 
 the tissues, to destroy them before they can multiply sufiiciently 
 to cause disease. 
 
CAUSES AND EFFECTS OF MOUTH INFECTION 1 9 
 
 General Causes of Mouth Infection.^ — With such a picture 
 of bacterial invasion before our eyes, we are confronted with a 
 problem that for centuries interested the philosophers as to 
 which comes first, the egg or the owl. That there are two causes 
 of bacterial invasion — the systemic and the local — is unques- 
 tionable, but in any particular case it is usually difficult to say 
 whether the original multipHcation of an infecting bacterium 
 first arose from deficient bactericidal power of the blood, or 
 whether a local bruising or infiltration of the tissues reduced 
 their defensive power against the germs to a degree where even 
 healthy blood might not be able to resist the bacterial growth 
 and consequent onset. However this may be, there is no doubt 
 that progressive weakness in either systemic or local resistance 
 will infallibly result in a final depression that is characteristic 
 of both. 
 
 For instance, the constant drinking of water or beer containing 
 lead will cause a systemic depression that, in addition to a palsy 
 of the wrists and intestinal derangement, also causes the blue 
 line of gum infection around the teeth that is diagnostic of 
 chronic lead-poisoning. In the same way the constant use of 
 calomel as an internal medicine wiH cause such a destructive in- 
 flammation of the gums around the teeth that the latter will 
 loosen and even drop out. In each instance the primary cause 
 of the bacterial invasion of the gums is systemic, and the ever- 
 present micro-organisms first obtain their lodgment in a mass 
 sufficient to defy the contending tissue-cells solely because of a 
 general depression of the body at large. If, however, after the 
 abscesses around the teeth are fully established in an area of dead 
 and dying tissue, the lead or calomel is stopped and that which has 
 been taken is elimmated by the mtestines and kidneys, the ab- 
 scesses around the teeth may nevertheless continue because the 
 tissue-ceUs around them lack their original germicidal power. 
 And even if the blood generally should regain its normal germi- 
 cidal power, it would be unable to effectively reach and combat 
 the invading masses of infection that are now securely fortified 
 behind the dead or weakened tissue-cells; and the invading 
 germs will continue to feed, and just as surely advance their 
 
20 MODERN DENTISTRY 
 
 devastations wherever the tissue-cells show further weakened 
 resistance. 
 
 As an illustration of a purely local source of mouth infection, 
 let us take, for example, a tooth that starts to decay through the 
 impaction of food in an improperly developed fissure of the 
 enamel. The food ferments and acid is formed that dissolves 
 and softens the tooth substance so that bacteria can penetrate 
 along the dentin filaments to the nerve, or pulp, as it is called. 
 The blood in the pulp throws out a protecting layer of tooth bone 
 between it and the infection. Finally, the pulp loses the power 
 of producing immunizing substances with which it can combat 
 the disease, and accepts the infecting germs, which it deposits 
 in the gum around the tip of the root. An infected living pulp 
 may cause abscesses that are self-perpetuating and that will 
 infect the system at large. This will finally lower the body 
 resistance, and so the infection that started in a purely local 
 manner may end in general disease. 
 
 As above stated, the systemic cause of mouth infection 
 may not only be tuberculosis, malaria, rheumatism, typhoid 
 fever, or any of the major diseases common to man, but it may 
 be merely a bad cold or a passing attack of grip, which by lower- 
 ing the vital resistance will allow the self-perpetuating abscesses 
 of mouth infection to be formed. And it is equally true that a 
 mouth infection caused by a badly fitting crown or a filth-col- 
 lecting bridge may be the primary cause of systemic depression 
 that will allow the body to become a prey to any of the systemic 
 diseases or infections just mentioned, when without such local 
 infections the body might have had sufficient vital resistance to 
 repulse the onset of systemic disease and maintain a normal con- 
 dition of health. 
 
 The obvious cure for mouth infection of a purely systemic 
 origin is the removal of the cause of the systemic depression, 
 but as this deals with practically the whole realm of general 
 medicine this phase will not be discussed here. The obvious 
 cure for mouth infections of local origin is also the complete 
 removal of the cause, and with that thought in our minds the 
 various local causes of mouth infection will now be considered. 
 
CAUSES AND EFFECTS OF MOUTH INFECTION 21 
 
 Local Causes of Mouth Infection.— The most fruitful local 
 causes of mouth infection are improper mastication of food 
 and inefficient daily cleansing of the mouth. Nine-tenths, if 
 not ninety-nine-hundredths of the local mouth infections can be 
 traced fundamentally to these two great causes. All the other 
 causes follow after these almost as a matter of course, such as 
 decay of the teeth, and infection and death of the dental pulps 
 or "nerves." Next follows impaction of food between the teeth, 
 with the consequent destruction of the gum that protects the roots. 
 The bone between the teeth, being exposed, becomes infected 
 and absorbed, leaving a hole or pocket that cannot be properly 
 cleansed; and this pocket, therefore, becomes a permanent and 
 ever-spreading focus of disease, so that the membrane supporting 
 what may be a perfectly healthy tooth gradually breaks down 
 more and more, until the nerve trunk and blood-vessels at the 
 root tips become infected and finally destroyed. This causes 
 the death of the pulp in a tooth that may not show external signs 
 of decay. Thus another depot of infection is formed that can 
 only be eliminated by boring into the tooth, removing the pulp, 
 and sterilizing and filling the root canals. 
 
 The fact that a tooth without decay, containing a Hve pulp, 
 or nerve, may be a source of infection makes the diagnosis of 
 whether there is mouth infection a matter of great nicety. The 
 fact that a tooth with poison-spreading chronic abscesses may 
 be perfectly normal in appearance, sensation, and function 
 still further adds to the difficulty. This matter of diagnosis 
 will be minutely discussed later on, but its difficulty makes 
 the discovery of masked mouth infection by the general prac- 
 titioner a matter of great uncertainty or even impossibility, 
 unless the physician has had the necessary diagnostic instruc- 
 tion in this most important subject. Only too often do 
 physicians make careful general systemic examinations, but 
 take merely a casual look at the teeth and gravely pronounce, 
 "no mouth infection." Tuberculosis of the lungs is easily recog- 
 nized in its advanced stages, but it is cured in exact ratio to its 
 early diagnosis, and the spread of systemic disease by mouth 
 infection is in the same manner prevented by its early recog- 
 
22 MODERN DENTISTRY 
 
 nition. As a matter of fact, the general practitioner only recog- 
 nizes mouth infection in its advanced stage, when many of its 
 systemic sequelae are already firmly intrenched. 
 
 The packing of food between the teeth, whether there is 
 decay or not, should always be considered a forerunner of mouth 
 infection with the probable consequent loss of the teeth. The 
 packing of food between the teeth, as above stated, is not always 
 associated with decay, but may be due to a gum infection alone 
 which weakens the supporting membrane about the teeth. These 
 teeth spring apart under the force of mastication with resultant 
 bruising of the gum and ultimate pockets of infection. We also 
 have pockets of infection between the teeth that owe their 
 origin to the projecting edges of fillings and ill-fitting crowns 
 that during mastication constantly drive the infection into the 
 helpless gum. Furthermore, infection is caused by uncleansable 
 bridges, frequently inserted over gums already infected, and by 
 plates that are made primarily to aid mastication, while in only 
 too many instances they hasten the destruction of the teeth that 
 they are designed to supplement. 
 
 These facts are so obvious that a glance in the average mouth 
 will show instances of such infection again and again. And it is 
 not as though such crowns and bridges were considered anti- 
 quated. They are approved and recommended in the every-day 
 curriculum of many of our leading dental colleges by faculties 
 that complacently look on their work as largely a question of 
 mechanics, while their mechanical teachings and methods 
 continue to spread infection and disease. 
 
 Dentistry is rapidly coming to be one of the foremost 
 branches of preventive medicine, and in a short while no den- 
 tist will be allowed to practice unless he also has general medical 
 training. Those who do not recognize this vital fact and con- 
 tinue to practice methods that create and perpetuate mouth 
 infection will soon be relegated to obHvion, while a new and more 
 scientific class of men will take their places. 
 
 Many interesting experiments have been made with the Strep- 
 tococcus viridans, a germ which is frequently found in the pockets 
 of mouth infection. Injected into the ear of a rabbit whose 
 
CAUSES AND EFFECTS OF MOUTH IISTFECTION 23 
 
 heart had been artificially strained, the Streptococcus viridans, 
 upon autopsy, has been recovered from the inflamed valves of 
 the heart. A macroscopic study of such animal postmortem 
 heart specimens has sometimes shown a calcareous deposit that 
 is not dissimilar to the inflammatory calcareous deposits found 
 on the roots of teeth. This is particularly interesting as there is 
 unquestionably a relation between tooth tartar and general 
 systemic depression due to mouth infection, the mouth tartar 
 decreasing perceptibly as the immunizing bodies of the blood 
 become more and more in control of the situation. 
 
 Effects of Mouth Infection. — ^The following case is an inter- 
 esting example of secondary infection from a pyorrhea pocket: 
 A young physician declared that he believed the condition of his 
 teeth was causing a swelhng of his tonsil. A casual look in the 
 mouth gave the impression of gums that were perfectly healthy, 
 but an exploration between the upper second and third molars 
 revealed a pocket that almost exposed, the tips of the adjacent 
 roots of both teeth. An appHcation was made of ammonium 
 bifluorid. The patient returned in a week and the tonsil that had 
 been greatly swollen had practically returned to its normal size. 
 And from then on during the treatment it was clearly demon- 
 strated that as the pocket showed signs of reinfection the tonsil 
 would swell, and that when the pocket finally yielded to medi- 
 cation the tonsil returned to its normal state. This case shows an 
 intimate relation between the tonsils and gum infection, appar- 
 ently indicating that where they exist in common all the disease 
 previously attributed to the tonsils alone may equally as well be 
 attributed to gum infection. 
 
 Another case was that of chronic infection of the internal 
 ear. The physician was unable to find any local cause, and sug- 
 gested that the trouble arose from reflex dental infection. The 
 removal of an infected Hving pulp in the upper second molar 
 caused the ear to clear up immediately. 
 
 A patient had a chronic abscess in an upper molar that was 
 associated with pronounced swelling of the submaxillary salivary 
 gland on the same side. When the infection in the upper jaw 
 was treated the gland in the lower jaw returned to its normal 
 
24 MODERN DENTISTRY 
 
 size; but when the infection returned, as it did several times 
 because the patient would not take his treatments with proper 
 regularity, the submaxillary gland would invariably become 
 swollen again. When the tooth became cured of its infection, 
 the gland regained its normal condition permanently. 
 
 These cases are presented to show the intimate connection 
 between the gums and tonsils, the gums and the ear, and the 
 gums and the salivary glands. A more extraordinary case was one 
 where the infection of a lower second molar caused a partial loss 
 of sight in the eye on the same side of the face. In the course 
 of examining the teeth of a young woman the author noticed a 
 submaxillary swelhng. This was traced to the second molar, 
 which, on being opened, revealed an infected pulp. This pulp 
 was removed and the tooth treated antiseptically for a series of 
 treatments, during which the submaxillary gland decreased in 
 size as the antiseptics were appHed. After the first treatment 
 the patient said that her sight was much improved. Later on, 
 with each treatment, she spoke of the continued improvement 
 of her eye, and finally, when the tooth was cured, she said as she 
 left, "I had to give up my art studies on account of that eye, 
 but I am now going to return to them." Later she went to her 
 oculist, who six months before had found her sight in that eye 
 more than half gone, and he corroborated her statements by an 
 examination, and found that the chronic inflammation had en- 
 tirely disappeared. 
 
 There are other cases where the connection between mouth 
 infection and general arthritic conditions is clearly established 
 by the fact that when the mouth infection was remedied the gen- 
 eral diseases either cleared up or were greatly improved. 
 
 This chapter will close with a most interesting case of spinal 
 irritation connected with mouth infection. A young married 
 woman, thirty years of age, came to the author for treatment. 
 About five years previously she had had an automobile accident 
 by which the base of her spine had been so injured that it was 
 impossible for her to remain in a sitting posture for more than 
 half an hour at a time. Two or three of her teeth showed so 
 marked a sensibility to heat and cold that the pulps, or 
 
CAUSES AND EFFECTS OF MOUTH INFECTION 2$ 
 
 nerves, had to be removed. The teeth also showed irritation at 
 the root tips characteristic of spinal irritation, which made it 
 practically impossible to fill the nerve canals. Any such attempt 
 was accompanied by such pain and signs of suppuration that no 
 progress of any sort was made for over a month. Finally, a 
 sterilized piano-wire drill was passed down a sterilized root canal 
 and plunged into the sensitive area at the root tip; a material 
 was obtained which yielded only a single type of streptococcus. 
 From this an autogenous vaccine was made and the patient 
 was treated with the vaccine about eight times, once each week. 
 After the fourth treatment it was quite possible to fill the canals 
 of air the teeth where the nerves had been removed. After the 
 eighth treatment she was able to sit up, and since that time has 
 had no further trouble with her spine. Evidently the infection 
 of the teeth and the infection of the spine came from the same 
 germ, and the systemic cure of the gums at the same time cured 
 the spine. 
 
 Medical literature is full of startling cases where the intimate 
 interdependence of mouth infection and grave general systemic 
 disease is clearly indicated, but these just mentioned are of in- 
 terest as they have come under the author's personal experience. 
 
 However, this chapter cannot be brought to a close without 
 emphasizing the fact that leukoplakia (a white semi-malignant 
 growth), tuberculous abscesses, Vincent's angina, a rapidly pro- 
 gressive infection, and cancer of the mouth are all so closely 
 associated with a history of tooth and gum infection as to make it 
 a matter for serious consideration whether any of these dreaded 
 diseases may not be a direct result of the ordinarily neglected 
 every-day diseases of the teeth and gums. 
 
 The normal age of man is now the biblical threescore and ten, 
 but when the simple rules for preventing mouth infection are 
 generally known and enforced as a matter of public poHcy, one 
 cannot foretell how much human Kfe will be extended, but that 
 it will be greatly extended there is every reason to believe. 
 
CHAPTER II 
 
 PREVENTION OF MOUTH INFECTION 
 
 Mouth Cleansing. — The most important treatment in the 
 prevention of mouth infection is the mechanical removal of the 
 masses of disease germs from the teeth and gums. After this has 
 been done a mild antiseptic wash, such as a i per cent, solution 
 of peroxid of hydrogen, held in the mouth for a minute or two, 
 will be able to inhibit the growth of the remaining bacterial 
 film until it is time to cleanse the mouth mechanically again. 
 For germs of disease are dangerous not only as germs, but they 
 are dangerous in direct proportion to their number and the 
 length of time they are permitted to make their attack on the 
 tissues. The immunizing bodies of normal blood can readily re- 
 sist a few germs of disease for an indefinite time, but when the un- 
 disturbed germs are allowed to grow indefinitely the resistance 
 of the tissue-cells is overthrown through a continued, ever-in- 
 creasing efficiency of attack. Therefore it is evident that the 
 fundamental remedy is to keep the ever-present disease germs 
 reduced to a film so thin that the resistance of the blood in the 
 gums will always be able to cope with any depressing influence 
 that such a small bacterial mass can develop. It is also essential 
 to keep the bacterial masses on the teeth so thin that they cannot 
 secrete enough acid to effect a softening of the enamel through 
 which the germs may find an entrance into the interior of the 
 tooth substance. 
 
 The three acknowledged means of removing and inhibiting 
 the growth of the bacterial masses are: (i) the floss-silk; (2) 
 the tooth-brush; (3) the mild antiseptic wash. The scientific use 
 of the floss-silk is absolutely essential in the daily cleansing of 
 the mouth, and yet the reasons underlying its scientific use are 
 not generally understood. It is, of course, useful in removing 
 
 26 
 
PREVENTION OF MOUTH INFECTION 27 
 
 particles of food that may act as culture-media for the growth 
 of disease germs, but the greatest function of floss-silk is to remove 
 the mass of germs themselves that would otherwise day by day, 
 week by week, and month by month steadily collect between 
 the teeth. There is no other means than the floss-silk for effec- 
 tively removing these masses from between the teeth. 
 
 Dentistry has recommended pitifully inadequate movements 
 of the tooth-brush for cleansing between the teeth, when a single 
 glance in the mouth immediately after the teeth have received 
 such a brushing will show that the tooth-brush does not and 
 cannot cleanse between the teeth. In teaching such misleading 
 methods of tooth cleansing dentistry has been perpetuating 
 the very conditions it professes to obviate. As before stated, 
 the only instrument capable of cleansing the spaces between 
 teeth is floss-silk, and this should be swept over each approxi- 
 mating surface of the teeth at least once a day. This will break 
 up and remove the bacterial masses that would otherwise coUect 
 and remain year in and year out. It is because the tooth-brush 
 erroneously is supposed to remove such bacterial deposits that 
 tooth decay nine times out of ten starts between the teeth; and 
 almost invariably pyorrhea alveolaris (Riggs' disease) or gum 
 infection starts between the teeth as soon as the gum has receded 
 sufficiently to make an interdental space. Because floss-silk 
 is not properly used, and the masses of bacteria remain undis- 
 turbed, mouth infection starts between the ages of five and ten, 
 and eventually reveals at the age of forty or fifty its insidious 
 toll of general disease. Almost all, if not entirely aU, of these 
 dreadful sequelae can be avoided if at the age of five the child 
 is taught the use of floss-silk, and is taught to cleanse between 
 the teeth not for the sake of being clean, but for the sake of 
 growing up strong and healthy. No child wishes to take the 
 trouble to be clean, but every child wishes to grow up strong 
 and weU. Every normal child wiU labor and strive to improve 
 his body for the sake of athletics, and if he knows that the 
 use of floss-silk is Just as necessary as arduous exercise, there 
 is no question but that floss-silk wiU be used, and used effec- 
 tively. 
 
28 MODERN DENTISTRY 
 
 Let US now consider the use of the tooth-brush as a means of 
 removing the bacterial masses from the exposed surfaces of the 
 teeth and the gums. Just as those who never use floss-silk never 
 cleanse between the teeth, so do the majority of those who brush 
 the teeth never really cleanse them. The cleansing action of a 
 tooth-brush can only lie in bristle friction, and most well-meaning 
 people either use strokes of the brush that never get beyond a 
 pivoting of the long bristles, or they use brushes so large that 
 there is neither room to move them nor to effectively place them 
 against the back teeth. With all the talk that there has been 
 about tooth-brushing since Adam delved and Eve span, the 
 wisdom-tooth has been as badly treated as the nearsighted child 
 of fifty years ago who was relegated to the dunce cap because 
 he could not see the letters of the book that he was blamed for 
 not understanding. The wisdom-tooth enamel is in structure just 
 as sound as that of any other tooth, and it has its bad name 
 simply because it is never cleansed. Because the back molars 
 are badly cleansed they are usually the first to become infected 
 and loosen. The back molars are nearest to the tonsils and, 
 being uncleansed, they are therefore particularly dangerous 
 as spreaders of disease. 
 
 The great test of a tooth-brushing method is, does it cleanse 
 where it is designed to cleanse? In plain words, the way to brush 
 the teeth and gums is to brush them. Obviously, too large a 
 brush is useless. To use a 2-inch brush with bristles |-inch long, 
 where there is only 2| inches for free action, means that there will 
 be practically no bristle friction, which is what occurs in most 
 mouths during the process of brushing the teeth. In the mouth 
 the free space in any given Kne where a tooth-brush can operate 
 is seldom over 2| inches. The usual brush, being about 2 inches 
 long, generally reduces . the possible movement of the brush to 
 about I inch, and this \ inch is entirely taken up by the spring 
 and pivoting of the bristles, so that with any such attempt at 
 brushing there is very little bristle friction at all. Therefore we 
 should avoid the use of the ordinary large tooth-brush and use 
 a narrow bristle brush not over i| inches long, with bristles not 
 over I inch in length. This will allow sufficient room for genuine 
 
PREVENTION OF MOUTH INFECTION 
 
 29 
 
 motion of the brush in the mouth ; and if the bristles are too stiff 
 at first, the brush should be placed in hot water for a minute 
 before using, until the gums become accustomed to their action. 
 Healthy gums can bear the same scrubbing as the flesh around 
 the finger-nails, and with the same benefit. In fact, the exposed 
 surfaces of unhealthy inflamed gums, when given a vigorous 
 scrubbing with a stiff brush twice a day, in the course of a week 
 or ten days will become firm and healthy; and no other single 
 treatment, to the author's knowledge, will accomplish the same 
 result. This generally unknown fact was utihzed some years 
 ago by a certain charlatan who was trying to sell his tooth-paste. 
 He forced his way into the office and immediately began, ''Doc- 
 tor, this tooth-paste is most useful for the cure of the small canker 
 sores that so often come on the cheek and gums. All you have 
 to do is to put a Httle of this paste on the tooth-brush and brush 
 it thoroughly into them." "But," I interposed, "won't the sores 
 get well if they are brushed with the tooth-brush and water?" 
 "Why, yes," he replied, with a sickly smile, "but that is not 
 usually known." 
 
 The brushing of the gums, as before stated, is of prime impor- 
 tance, but the intense pain occasioned by the first week's work 
 is as severe as the pains in the back of an athlete when he first 
 starts to get himself into condition. The trainer tells the athlete 
 to go on with his work and that it will be all right, and in the 
 same way tb.e poor patient, though he fears that he is injuring his 
 gums when he uses the brush vigorously, must be encouraged 
 by his dentist to continue, with the assurance that the pain in 
 his gums will soon disappear. The author once showed a young 
 lawyer how to brush his teeth and gums. He went away and the 
 next day the author received a letter from him threatening suit 
 for having ruined his face. Amusing as this incident is, it has a 
 very serious bearing. The gums to be healthy must be scrubbed 
 so as to remove the bacterial masses and also the dead epithelial 
 scale, which will act as a bacterial food. Scrubbing infected 
 gums cannot result at first in anything but further infection that 
 may, and frequently does, cause a slight fever, however, the 
 bacteria cannot be removed and the gums will not heal unless 
 
30 MODERN DENTISTRY 
 
 this severe ordeal is endured. The systemic reactions caused at 
 times by brushing infected gums must be explained as a process 
 of auto-inoculation, for under no other supposition is it possible 
 to explain why, under the newly inaugurated thorough brushing 
 day by day, the gums should continue to be sore and inflamed, 
 and then suddenly, between the seventh and tenth days, become 
 healthy, hard, and firm, thereafter standing with complacency 
 any amount of brushing. 
 
 In a minor degree the same phase is noted when the floss-silk 
 is first used on infected gums. The gums at first naturally bleed 
 
 Fig. I. — Preliminary position of the dental silk. Note that it is attached solely 
 
 to the little fingers. 
 
 and become further infected from the use of a string that drives 
 in the infecting organism. This soreness has been used as an 
 argument against the use of floss-silk, but it is not a just argu- 
 ment, as a few days' perseverance will invariably show. The 
 persevering scientific use of floss-silk will always be followed by 
 improvement, and, if the infection has not proceeded too far, 
 by a complete disappearance of the infection between the teeth. 
 If the patient was told that he must go through a week or ten 
 days of discomfort to avoid gout, rheumatism, valvular heart 
 
PREVENTION OF MOUTH INFECTION 3 1 
 
 disease, or ulcer of the stomach, how readily and gladly would 
 he do it, how cheap would he consider the price! But since he 
 
 Fig. 2. — Method of holding the dental silk while cleansing the upper teeth. 
 
 considers it a question of mere cleanHness, this ordeal is very 
 naturally avoided and these diseases all become possibilities. 
 
 Fig. 3. — Method of holding the dental silk for cleansing the lower teeth. 
 
 Method of Using Floss-silk. — Careful floss-silking is not 
 the simple procedure it is supposed to be. Like tooth-brushing, 
 there is only one way to do it properly and a hundred ways to do 
 it improperly. The floss-silk must scrape the sticky bacterial 
 
32 MODERN DENTISTRY 
 
 masses from the sides of the teeth and the intervening gum. 
 Many instruments have been devised to hold the silk, but none 
 can equal the fingers themselves for doing this most important 
 act. The proper method of using floss-silk is as follows: A gen- 
 erous piece of floss-silk should be taken and wrapped around 
 the little fingers of both hands so that there will not be more 
 than ^ inch of free silk between the two hands (Fig. i). The 
 thumb and forefinger are used for cleansing the upper teeth 
 (Fig. 2), the two forefingers for cleansing the lower teeth (Fig. 
 3). There should not be a greater length of free silk. For in- 
 stead of cleaning the bacteria off the teeth too great a length 
 of free silk will bend and pivot like the bristles of the brush, 
 which are too long. The tense span of silk should go with a 
 sliding motion up one side of the interdental space, care being 
 
 A A 
 
 Fig. 4. — Triangle A-B-C shows correct lines dental floss should travel in cleans- 
 ing each interdental space. 
 
 taken to include the curve of the tooth on that side, up well 
 under the frenum of the gum, then roughly across the gum and up 
 into the opposite frenum, and then down the rounded surface 
 of the adjacent tooth. For instance, let A (Fig. 4) represent 
 the junction of the two upper central incisors, B represent the 
 frenum of the gum on one side, and C represent the frenum on the 
 other side. The floss-silk must pass through the junction A , and 
 shpping and sliding across the rounded side of the tooth, with a 
 drawing motion from A to B, must then scrape across the gum 
 to the frenum C, into which it must be driven, and finally scrape 
 down the rounded surface of the tooth from C to ^ . It travels 
 the outline of a triangle (Fig. 4). 
 
 The mere passing of the thread through ^ in a straight line, 
 as is the custom of most people who use floss-silk, is obviously 
 
PREVENTION OF MOUTH INFECTION 
 
 33 
 
 ineffective, since the bacteria stick to the sides of the teeth and 
 gums Uke films of glue and can only be removed by actual, vigor- 
 ous scraping. The mere passage of the silk up and down through 
 A is as useless and silly a performance as that of attempting to 
 cleanse the bacterial masses from the teeth by merely rinsing 
 them with a wash. A mouth-wash can no more remove the 
 bacterial masses from the sides of the teeth than it could remove 
 a coating of fresh varnish if such had been flowed on the dried 
 
 i^<.»i-ta. ^ jiiiytrijif' If 
 
 Fig. 5 —Correct position of hands in flossing right half of upper dental arch. 
 Note that the thumb of right hand is on the outside. 
 
 teeth previous to the cleansing. This adhesive nature of the 
 bacteria must be recognized, or otherwise successful flossing of 
 the teeth will be impossible. 
 
 In cleansing the teeth on the upper right side the thread 
 
 should be stretched between the index-finger of the left hand 
 
 and the thumb of the right hand. The thumb should be on the 
 
 outside and the index-finger on the inside of the mouth (Fig. 5). 
 
 3 
 
34 
 
 MODERN DENTISTRY 
 
 The triangular motion should then be carried out between all 
 the teeth all the way back to the farthest molar, care being 
 taken to see that the thumb slips under the hp when the molars 
 are reached. When this has been accurately done there will be 
 no difficulty in reaching behind the wisdom tooth. There is no 
 instrument yet devised that can hold the floss-silk as well as the 
 fingers. 
 
 When we come to cleansing the interdental spaces on the 
 upper left side the left thumb should be on the outside and the 
 
 Fig. 6. 
 
 -Correct position of hands in flossing left half of upper dental arch, 
 that the thumb of left hand is on the outside. 
 
 Note 
 
 right index-finger should be on the inside (Fig. 6) . The procedure 
 for cleansing the spaces of the upper left side is the same as for 
 the upper right side. 
 
 In cleansing the spaces of the lower right side the free silk 
 must extend between the index-fingers, the right index-finger 
 being on the outside for the lower right side (Fig. 7), and the left 
 index-finger being on the outside of the teeth for the left lower 
 
PREVENTION OF MOUTH INFECTION 
 
 35 
 
 side (Fig. 8) . In other respects the same principle for cleansing 
 the spaces is to be observed. 
 
 The Method of Brushing the Teeth. — As before stated, the 
 tooth-brush should not be over i| inches long, the bristles not 
 over I inch long, and the handle long and large enough to afford 
 a firm grip to the hand (Fig. 9, small brush; Fig. 10, large brush, 
 which is obxdously too large). The principal thing to be avoided 
 is too great bristle length, since long bristles by increasing the 
 
 Fig. 7. — Position of hands in flossing right lower side of dental arch, 
 the index-finger of the right hand is on the outside. 
 
 Note that 
 
 pivoting arc of each bristle just so much reduce the bristle 
 friction produced by the general movement of the brush. It 
 is bristle friction alone that cleanses the teeth and gums during 
 the process of brushing. Bristles | inch long can pivot f inch 
 each way without bristle friction. If, therefore, there is a i-uich 
 stroke, the bristie friction stroke is only I inch, and if, as fre- 
 quently happens, the tooth-brush stroke is only | inch, there is 
 no bristie friction stroke at all. The i-inch bristle, under the 
 same conditions, would have a play each way of 1^ inch, which 
 
36 MODERN DENTISTRY 
 
 theoretically would cause only f inch loss of bristle friction, but 
 in reality it would be less, since the further the bristle extends 
 from the back of the brush, the more readily it bends under 
 pressure. But granting that there was f inch loss in bristle 
 friction to each stroke, this would still leave a real cleansing 
 friction stroke of f inch when the i|-inch brush was moved 
 through a 2|-inch space, the amount of space for tooth-brush 
 motion usually found in the average adult mouth. 
 
 Fig. 8. — Position of hands in flossing the left lower side of dental arch. Note 
 that the index-finger of left hand is on the outside. 
 
 So much for the mechanics of tooth-brushing; now as to the 
 actual motions as appUed to the human mouth. There are three 
 motions: First, the rotary motion, whereby all the gums and 
 teeth anterior to the second molars are cleansed with a vigorous 
 whirHng action; second, the drawing motion, wherein the middle 
 of the brush is placed behind the last molar and drawn vigorously 
 across the outside gum margins of the teeth; third, the drawing 
 motion, wherein the brush is placed back of the last molar in- 
 
PREVENTION OF MOUTH INFECTION 37 
 
 side of the mouth and drawn sharply forward along the gum 
 margins and the teeth. In each stroke care should be used to 
 follow the curve of the arch with the entire face of the brush. 
 
 ■■ UlUlllB 
 
 jrig_ Q_ — Actual size of brush that can properly cleanse the teeth and gums. 
 
 Let us now discuss motion No. i in its minute details. The 
 upper and lower front teeth should be placed edge on edge to 
 avoid the lapping of the upper teeth over the lower. The 
 brush should then be placed against the teeth and rubbed up- 
 
 Fig 10. — Actual size of brush ordinarily used. 
 
 ward to the junction of the upper gum and lip, forward for a 
 distance of a full inch or more, downward to the lower gum and 
 lip margin, and then back to the original position, as shown in 
 Fig. II. This should be done at least five or six times. The 
 
38 
 
 MODERN DENTISTRY 
 
 brush should then be placed between the cheek and teeth on the 
 left side. Here the same general motions should be carried out. 
 The brush should be rubbed upward to the juncture of the cheek 
 and gum, back to where the end of the brushing is stopped by the 
 
 Fig. II. — Motion of brush for cleansing front teeth and gums. 
 
 overhanging crr^^e of the lower jaw, down to the juncture of the 
 cheek and lower gum, then back to the start, as in Fig. 12. This 
 same motion should be repeated on the right side, and the three 
 
 Fig. 12. — Motion of brush for cleansing side teeth and gums. 
 
 movements of motion No. i are finished. If after this motion has 
 been thoroughly performed the second and third molars, upper 
 and lower, are examined, they mil still be found covered with 
 bacterial masses, and the reason for these undisturbed deposits 
 
PREVENTION OF MOUTH INFECTION 39 
 
 is easily discovered. The curving side of the lower jaw lies so 
 close to the upper teeth that no tooth-brush can effectively get 
 at them while the jaws are closed, and in the same way the last 
 two lower teeth are excluded from the action of the brush by the 
 fact that they he behind and within the curving angle of the lower 
 jaw. When the jaws are closed there is not | inch room remain- 
 ing for tooth-brush cleansing, but when the jaws are partly 
 opened, the lower jaw swings back, leaving a space of a full | 
 inch in which the brush can thoroughly do its work behind the 
 third molars. ^ Therefore, as just intimated, in performing 
 motion No. 2 for the upper teeth the mouth should be about half 
 open and the Hps and cheek held relaxed. The middle of the 
 
 Fig. 13.^ — Position of brush preparatory to cleansing upper wisdom teeth. Dotted 
 line shows direction in which the brush should be drawn. 
 
 bristles of the i|-inch brush should be placed at the back of the 
 third molar and drawn briskly forward along the gum margins, 
 care being taken to follow the curve of the gum with the entire 
 face of the brush (Fig. 13). To place the brush behind the 
 third molar the relaxed corner of the mouth should be stretched 
 back by the back of the brush until the middle of the brush 
 is directly back of the wisdom tooth. When this is done correctly 
 the brush will be pointing directly at the wisdom tooth on the 
 other side of the arch. The middle of the brush should be placed 
 behind the third molar, not thrust in place by the point, as by 
 thrusting, the bristles will be so bent that the resulting pivoting 
 , of the bristles will cause the back of the upper third molar to get 
 
40 MODERN DENTISTRY 
 
 no bristle friction at all, and so the back of the third molars will 
 not be cleansed. Motion No. 2 in its action on the lower molar 
 teeth is exactly the same as with the upper, except that instead 
 of placing the bristles on the back of the lower third molar, the 
 bristles are directed downward on the gum back of the third 
 molar, and then with a curving, downward sweep are brought 
 sharply along the gum and cheek margins and the necks of the 
 lower teeth (Fig. 14). This motion should be done on the upper 
 and lower jaws, right and left, and not less than five or six times 
 each. 
 
 Motion No. 3 is comparatively simple. The brush is placed 
 on the gum and tooth line behind the third molars and drawn 
 
 Fig. 14. — Position of brush preparatory to cleansing back of lower wisdom teeth. 
 Dotted line shows the proper downward sweep. 
 
 sharply forward and out of the mouth over the insides of the 
 central incisors, care being taken to follow the curve of the arch 
 with the entire face of the brush. The brush should be placed 
 back of the last molars, not thrust back of them, as thrusting will 
 cause a counterbending of the brush bristles and result in a 
 pivoting that again will leave the back molars without bristle 
 friction, and consequently dirty, (Fig. 15). Motion No. 3 should 
 be done five times on the upper and lower jaws, right and left, 
 and when this has been properly done the surfaces of the teeth 
 and gums will be free from bacterial masses. 
 
 After so much minute explanation it may not be inadvisable 
 to review once more just what the daily cleansing of the mouth 
 
PREVENTION OF MOUTH INFECTION 4I 
 
 should be. The surfaces between the teeth should be thoroughly 
 swept by floss-silk to remove all food and bacterial deposits. 
 The teeth and gums should then be thoroughly brushed, as 
 described, with dentifrice or antiseptic mouth-wash (see Chapter 
 III), and the saliva and mouth-wash vigorously swashed in 
 between the teeth for a period of not less than two minutes, so 
 that the thin coating of bacterial film left by the floss-silk on 
 the sides of the teeth may be discouraged from growth until 
 the next cleansing. Where there is marked gum infection a 
 saturated solution of sodium silicofluorid or i per cent, peroxid 
 solution should be held in the mouth for at least two minutes 
 
 Fig. 15. — Position of brush preparatory to cleansing inside of dental arches. 
 The brush must extend well back of the back tooth and be drawn briskly forward 
 along the edge of the gum and teeth, and finally out across the median line, as is 
 shown by the dotted line. 
 
 after the procedure just described. This cleansing should be 
 carried out morning and evening. It must not be forgotten, 
 however, that each mouth is a separate problem and must be 
 treated as such. If teeth are missing, the brush must be inserted 
 vigorously in the vacant spaces, and if certain abnormal rotations 
 are necessary the dentist must train the patient to see that these 
 abnormalities are met and the parts are thoroughly cleansed 
 by especially devised strokes of the brush. 
 
 Figure i6 represents a pronounced case of mouth infection. 
 An examination revealed the fact that the infection was super- 
 ficial in the gum and had not penetrated along the teeth so as 
 
42 MODERN DENTISTRY 
 
 to cause abscesses that were beyond the reach of the floss-silk 
 and tooth-brush. A systemic examination proved the patient 
 to be in good general health. The patient was accordingly told 
 that if he would scrub his teeth and gums according to the author's 
 directions, and also use floss-silk as described, he could cure him- 
 self without any other treatment or even antiseptics. The patient 
 came back in four days and another photograph was taken (Fig. 
 17). Note the wonderful change in color,showing that the gums 
 had become almost normal. He was told to keep up the floss- 
 silking and gum-brushing, and not to use any dentifrice or 
 mouth-wash. He came back in a week, and while his mouth 
 showed considerable improvement, there was a large ulcer still 
 present. The author told him that by this time he expected the 
 mouth to be entirely well. He said, "I don't know what more 
 I can do, doctor, for I brush my gums thoroughly three times a 
 day." "Brush them once a day," was the reply, "and give the 
 poor ulcer a chance to get well." In this instance the patient 
 had been overstrenuous in carrying out instructions. He 
 went away and in four days more returned, and the third picture 
 (Fig. 18) is an illustration of how his mouth looked. When the 
 author first saw the patient, two weeks before, his gums had 
 the color of Fig. 16, and would bleed at the touch of floss-silk 
 or a brush. Two weeks later, through proper cleansing alone, 
 he could brush them as vigorously and as painlessly as he could 
 brush his finger-nails. There was no bleeding, his mouth was 
 healthy, and it not only looked clean, but it felt clean. Mouth 
 antiseptics and dentifrices have unquestionable value at times, 
 but for ordinary service their value is inconsiderable when com- 
 pared to efficient cleansing. 
 
 In closing this chapter it might be wise to emphasize the fact 
 that a brush softened in hot water is a valuable instrument with 
 which to commence to cleanse and harden infected gums. As 
 the gums become hard and firm the patient will naturally be less 
 careful about the use of hot water on the brush, and very soon the 
 stiff bristles can be fearlessly used. This precaution is especially 
 valuable in the preliminary training of children in their daily 
 mouth hygiene. 
 
Fig. 16. — Inflamed gums prior to using dental floss and tooth-brush properly. 
 
CHAPTER III 
 
 A STUDY OF TOOTH ENAMEL AND SALIVA 
 
 DENTIFRICES AND MOUTH-WASHES IN THEIR RELATION TO 
 MOUTH HYGIENE 
 
 Enamel Softening and Hardening. — Enamel softening has 
 been considered to be necessarily associated with roughening 
 of the surface, loss of luster, and dissolution of the substance that 
 binds the enamel rods together ; and whenever enamel decalcifica- 
 tion is. associated with decay of dentin this conception of enamel 
 softening is accurate. But this conception takes into considera- 
 tion only the final phase rather than the complete process of 
 enamel degeneration. 
 
 Miller and many others in producing artificial decalcification 
 by solvents, in employing aqueous solutions of acids var)dng 
 in strength from | to 2 per cent., have exposed their tests to 
 two serious objections: First, that the solutions found in the 
 mouth are saKva solutions, not aqueous solutions; second, that 
 any strength greater than i : 1000 of lactic acid or any similar acid 
 would practically never be fdund in the mouth. Unquestionably, 
 the acid set free from the bottom of a bacterial plaque adherent 
 to the enamel may be acid of any strength, possibly chemically- 
 pure, or concentrated acid may be developed in a cavity where 
 the opening into the mouth is small enough to prevent dilution 
 with saliva. But in the enamel degeneration which is associated 
 with general erosion, where the bacterial plaque is not an impor- 
 tant factor, decalcification tests to be of value must be made 
 with saliva solutions and with acid solutions as weak as those 
 found in the human mouth; for saliva itself restrains the action 
 of many acids on the teeth and modifies and changes the appear- 
 ance of enamel decalcification. 
 
 For instance, i : 1000 solution of lactic acid and water, at 
 mouth temperature, will cut tooth enamel in thirty minutes, 
 
 43 
 
44 MODERN DENTISTRY 
 
 producing a rough, white surface. A i : 20,000 lactic acid aque- 
 ous solution will at the end of three or four days leave the tooth 
 enamel unharmed to all appearances, and yet the outer surface 
 of the enamel will be found with the edge of the lancet to have 
 distinctly softened, a condition which is only found with a 
 lactic acid and saHva solution as strong as i : 500, and such 
 a solution has a decidedly acid taste and turns litmus brilliantly 
 red. This shows that ordinary saliva has a decided protec- 
 tive power against acids. In fact, in a number of experiments 
 with lactic acid and saliva, a i : 500 solution left the tooth enamel 
 absolutely unharmed. 
 
 The action of aqueous solutions of acid calcium phosphate 
 and acid sodium phosphate on the teeth has been mentioned by 
 various observers, extraordinary stress being laid on the fact 
 that these acid salts cause smooth white decalcification. As 
 a matter of fact, many acids in aqueous solutions cause smooth 
 softening if the solution is sufficiently weak. As said before, 
 saHva restrains the action of most acids up to a certain point, 
 depending upon the concentration of the acid. Beyond this 
 point we find the same smooth decalcification that we have 
 with the weak aqueous solutions, and finally the same rough, 
 white decalcification that we find in strong aqueous solutions of 
 acid. The saliva solution is ordinarily from ten to twenty 
 times weaker in its action on enamel than an aqueous solution 
 of the same acid strength. Acid sodium phosphate and acid 
 calcium phosphate are, however, intensely interesting in their 
 action not only in aqueous solutions but in sahva solutions. 
 Acid calcium phosphate (i : 5000 aqueous solution) and acid 
 sodium phosphate (i : 20,000 aqueous solution) at the end of 
 two days will- turn tooth enamel a cloudy, pearly white, with 
 a smooth surface. This surface is perceptibly softened to the 
 cut of a lancet. If, however, the tooth enamel is removed from 
 the solution before the process advances too far, the cloudy ap- 
 pearance will in time disappear, and the tooth enamel will re- 
 sume its normal appearance and hardness. This phenomenon 
 occurred so consistently not only with the acid salts mentioned, 
 but also with other acid solutions, that the possibility was made 
 
A STUDY OF TOOTH ENAMEL AND SALIVA 45 
 
 apparent that partially softened smooth enamel could reharden 
 of itself if the decalcification had not progressed too far. 
 
 The following test was therefore made : Two sound teeth with 
 enamel impervious to the lancet were each placed in a lobe of 
 an orange. These lobes were each placed in a bottle with a 
 few drops of ether to prevent fermentation, and kept at body 
 temperature for two days in an incubator. At the end of that 
 time the teeth were removed and examined. One tooth showed 
 a smooth, white translucent area of decalcification, running from 
 the cutting edge to about one-third of the distance to the neck. 
 The rest of the enamel was normal to all appearances, and yet 
 the surface, both of the white and of the apparently normal 
 enamel, was readily pared with a lancet. The other tooth 
 seemed normal, but here again the outer surface of the tooth 
 enamel was distinctly softened. This difference in appearance 
 was undoubtedly due to inherent differences in the enamel. 
 These teeth were then washed in water and kept in a specimen 
 of saliva at body temperature for two weeks. At the end of 
 five days there was a decided rehardening of the enamel surface 
 and the white area of decalcification had half disappeared. 
 At the end of ten days the enamel could no longer be scratched 
 with a lancet at the end of two weeks the white spot of decal- 
 cification had almost, if not entirely, disappeared, and both teeth 
 appeared perfectly normal. 
 
 The question then arose as to whether the carbon dioxid in 
 the saHva was or was not a cause of enamel deterioration. That 
 saliva does possess the power of restraining enamel from carbon 
 dioxid decalcification was proved as follows: A sound extracted 
 tooth was placed in an automatic soda water former (Fig. 19) 
 with 30 c.c. of saliva which had been obtained by chewing rubber. 
 The saliva was then charged with the carbon dioxid and the 
 sparklet placed in a culture oven at a temperature of 98° F. 
 for thirty days. At the end of that time the tooth was taken out 
 and appeared unharmed. The tooth was then washed and 
 replaced in a clean siphon with distilled water. This water 
 was then charged with carbon dioxid, as before, and replaced 
 in the culture oven for twenty-four hours. At the end of that 
 
46 
 
 MODERN DENTISTRY 
 
 time the enamel showed a chalky decalcification that could be 
 scaled off with the finger-nail. This experiment proved that 
 
 carbon dioxid does not attack tooth 
 enamel in the presence of saliva. 
 
 The author has also proved that 
 this protective power of saliva is 
 also exerted against lemon, orange, 
 grape, grape-fruit, strawberry, rhu- 
 barb and cherry.^ 
 
 These experiments on extracted 
 teeth with weak acid solutions and 
 tests with a sharp lancet, while 
 suggestive, did not seem sufficient 
 to estabHsh the doctrine that soft- 
 ened enamel could reharden; so, 
 while morally convinced of the 
 truth of this assertion, I immedi- 
 ately started to perfect a machine 
 that would show in the minutest 
 degree just how far a given force 
 would drive a standard punch into 
 sound enamel, partly decalcified 
 enamel, and rehardened enamel, if 
 such a rehardening did take place. 
 A microdynamometer (Figs. 20, 21) 
 was finally devised that could deliver 
 475 pounds pressure on a punch, the 
 penetration of which could be meas- 
 ured up to 1/600,000 inch. Something 
 approaching this accuracy was necessary, as it was found experi- 
 mentally that the scope of the average test lay usually within 
 1/100,000 inch. It was, however, decided to set the register so 
 that it would measure in units of 1/300,000 inch, which, as can 
 readily be seen, could be reduced by a table to microns or tenths 
 of microns, i micron being equal to 1/25,000 inch; twelve of the 
 machine units, therefore, being equal to i micron. The pres- 
 
 ^ Journal of the Allied Societies, June, 1908. 
 
 Fig. 19. — Type of soda 
 water former used in testing 
 the power of saliva to restrain 
 carbon dioxid from attacking 
 tooth enamel. 
 
A STUDY OF TOOTH ENAMEL AND SALIVA 
 
 47 
 
 sure was given by a mercury gage (9) to which the punch (2) 
 was attached. A micrometer screw and ratchet wheel (8), 
 supporting the anvil, was strongly connected by castings and 
 
 Fig. 20. — Microdynamometer. (Author's instrument.) 
 
 heavy drawn steel rods beneath to the mercury gage and punch. 
 On this anvil rests a slab (4) with parallel sides on which the speci- 
 men (i) to be tested was placed. The pressure was applied to 
 
48 
 
 MODERN DENTISTRY 
 
 the specimen by placing it on the anvil and raising the anvil 
 by the micrometer screw and ratchet wheel up against the punch 
 until the mercury marked the pressure desired. The penetration 
 
 Fig. 21. — Detail of microdynamometer. (Author's instrument.) 
 
 of the punch into the specimen was made known by a microscope 
 (6) equipped with a specially constructed filar micrometer (7), 
 the microscope being screwed firmly to the anvil. This microm- 
 
A STUDY OF TOOTH ENAMEL AND SALIVA 49 
 
 eter was then adjusted and set so that it could accurately divide 
 into the desired number of parts a glass scale (3) attached to the 
 punch. By this device all error in the use of the machine was 
 largely thrown uot, since only the relation between the punch 
 and the anvil was within the scope of measurement. In Figs. 
 20 and 21 the numbers 11, 12, and 13 represent the counter- 
 weight for the mercury gage, the ratchet screw for raising or 
 lowering the glass scale, and specimens prepared for use. 
 
 In making the various tests three punches were used : a heavy 
 steel punch with a flat hardened circular point, 0.02 inch in 
 diameter; an iridium-pointed punch for testing acid erosion, 
 0.02 inch in diameter and standing 25 pounds pressure without 
 showing compression; a diamond-pointed punch with a circular, 
 flat point, 0.02 inch in diameter that could be used in acid solu- 
 tions and would readily stand 100 pounds pressure — 25 pounds 
 pressure with the diamond point gives a penetration equal to 
 75 pounds with the steel point. This is no doubt due to the 
 greater sharpness of the diamond edge over the steel. 
 
 If, therefore, the specimen is so adjusted and set under pres- 
 sure that there will be no give between it and the anvil, it is pos- 
 sible to determine accurately within one-tenth of a micron just 
 how far the punch wiU penetrate under a given pressure. For 
 instance, the specimen is carefully ground with a specially adapted 
 section grinder (Fig. 22), so that there is a flat, large base. A 
 small spot bn the top of the enamel is ground parallel to the base. 
 This forms the area to be tested. Any pressure exerted on the 
 enamel spot by the punch is directly expended on the enamel 
 without any side give between the base of the specimen and the 
 anvil. The specimen with parallel sides is placed on an agate 
 slab with parallel sides (4) and the slab placed on the anvil. 
 The steel punch, let us suppose, is adjusted near the edge of the 
 ground enamel and given a pressure of 5 pounds. A reading 
 by the microscope attached to the anvil is then taken on the scale 
 attached to the punch. The pressure is then raised to the de- 
 sired amount, say 75 pounds, for a given time, and then the pres- 
 sure is reduced again to 5 pounds and another reading taken, 
 the difference on the scale representing the penetration of the 
 
50 
 
 MODERN DENTISTRY 
 
 punch. To shift the specimen under the point for the different 
 measurements the agate slab is moved, not the specimen on the 
 slab. This eliminates variations in the spring of the specimen, 
 since the compression of the parallel slab on the anvil under a 
 given pressure will always be the same. 
 
 Fig. 22. — A, Motor; B, stone for grinding specimen cemented to tlae platen C, 
 D, micrometer screw for raising and lowering the specimen; E, water tank with 
 tube for conveying water to the stone in motion; F, handle that swings specimen 
 backward and forward across stone in motion. 
 
 Five or more measurements were usually made for each speci- 
 men and the average taken. By this means the hardness and 
 strength of normal enamel can be shown, as can also the varia- 
 tions from the normal enamel caused by strong acids, watery 
 solutions of acids, saKva, fresh and stale, and acid saliva solu- 
 
A STUDY OF TOOTH ENAMEL AND SALIVA 51 
 
 tions; and the recovery of enamel when removed from such 
 solutions. 
 
 AU analytic analyses of saliva heretofore have been hampered 
 by the fact that the investigator started by first chemically break- 
 ing it up, thus largely destroying it as saliva. All analytic 
 investigation of saliva from a dental point of view up to the pres- 
 ent time has been inconclusive, owing to the fact that normal 
 saliva may be alkaline to lacmoid or congo red, neutral to Htmus, 
 and acid to turmeric paper, all at the same time. How saHva 
 reacts to lacmoid, litmus, or turmeric may be purely of academic 
 interest, but how it may act on enamel and dentin is a vital 
 question, and this machine has opened the way for enamel to 
 be its own indicator of how a saHva may affect it. Since the first 
 days of physiologic study, saliva has been a most tempting field 
 for investigation because it is the body secretion most easily 
 obtained in a living state. To the diagnostician it no doubt 
 eventually will be at least of equal value to urine, but up to the 
 present time it has not been. This may be due to the fact that 
 saliva is a living substance, and urine an effete product that 
 lends itself to a chemical analysis that would absolutely destroy 
 saliva as saliva. Chemical analysis that breaks up the indi- 
 viduahty of living saliva is of little more value in showing the 
 vital action of saliva than fried chicken would be in showing the 
 beauties of a cock-fight. I am far from discouraging saHva 
 analysis of any kind. Salivary extracts or chemical products 
 are interesting, but inconclusively related to the living action of 
 the secretion ; and therefore, while enzymes of a curious and even 
 therapeutic nature may be extracted from saliva, no one can prove 
 that they justly represent the action of the living secretion 
 unless some means are devised to make control tests with the 
 living saKva that show a corresponding action. The machine 
 just described makes it possible to test the acid-restraining power 
 of various living salivas on tooth enamel in relation to a standard 
 water solution of acid. Salivas vary in this power. The same 
 saliva may vary at different times, apparently according to the 
 condition of the patient. 
 
 The conditions, then, are as follows: During sickness the teeth, 
 
52 MODERN DENTISTRY 
 
 from clinical experience, are known to decay. This may be due 
 partly to acid medicine or lack of care, but with every allowance 
 for these sources of error it seems to be well estabHshed that severe 
 or chronic illness in some way may render the teeth susceptible 
 to deterioration. If a relation between approaching sickness 
 and a loss of acid-protecting power in the saliva could be estab- 
 lished, a beginning in the diagnostic testing of the Kving saliva 
 would have been fairly inaugurated. 
 
 Take, for example, the following test that was made on a 
 specimen of tooth enamel: One side was ground to a fiat, broad 
 base; on the other side the enamel was ground in a small cor- 
 responding parallel plane. This was placed on the anvil of the 
 machine and raised up against an iridium point, 0.02 inch in 
 diameter, until a pressure of 5 pounds was reached. A read- 
 ing was then taken on the micrometer scale and noted. The 
 anvil was raised up and down repeatedly until all give between 
 the specimen and the anvil disappeared, and the 5 pounds pres- 
 sure always gave the same reading. Then fresh lemon juice 
 and water, i : 100, was placed on the specimen around the point 
 and the point relaxed so that the fluid could readily get under- 
 neath. At certain intervals of time the pressure of 5 pounds 
 was tried and a reading taken, which showed a loss of tooth 
 structure as follows: 
 
 2 minutes 0.8 microns 
 
 5 minutes 1.2 " 
 
 10 minutes 1.4 " 
 
 35 minutes 2.3 " 
 
 60 minutes 2.8 " 
 
 Thus, in one hour there was a loss of 2.8 microns of tooth 
 enamel. This same test was then made on the same tooth 
 enamel with a fresh saliva solution of lemon juice, i : 100. 
 This solution turned litmus red and was distinctly sour, and yet 
 after an hour's application the enamel showed a loss of only 0.3 
 micron. We might, therefore, express the restraining factor of 
 the saliva as 28 :3. Numerous other tests have been made of 
 a similar nature and all seem to give consistent figures. They 
 almost invariably show the power of saliva to restrain the action 
 
A STUDY OF TOOTH ENAMEL AND SALIVA 53 
 
 of acid on enamel. They also show that some enamels are much 
 more resistant to decalcifying action than others. 
 
 As an illustration another test might prove interesting: 
 The specimen was ground longitudinally for a base along its 
 axis and a small parallel plane ground on the enamel of the op- 
 posite side. A solution of i : loo lemon juice and water applied 
 for an hour dissolved the enamel i micron; i : loo solution of 
 lemon juice and saKva applied for sixteen hours showed no 
 loss of tooth tissue at all. It was then tested with the steel 
 punch for hardness and was found so softened that more than 
 60 pounds pressure could not be withstood. The softened enamel 
 simply refused to support the punch under such a pressure. The 
 specimen was then placed in fresh saliva, and set in the culture 
 oven at blood heat for seven hours, the saliva being changed 
 every half-hour. At the end of that time the tooth was again 
 tested with the steel punch and was found to have so hardened 
 that 75 pounds pressure was readily withstood and a various 
 penetration noted of 3.5, 2.8, 3.2, and 4.5 microns. 
 
 Further tests made on sound enamel without the use of acids 
 show conclusively that the substance of normal enamel is much 
 harder on the outside surface than within, where it is not exposed 
 to the air or saKva. Surfaces tested immediately after grinding 
 have been known to harden from 15 to 30 per cent, when immersed 
 in saliva or exposed to the air for a period of a few hours or a 
 day. These tests have been repeated and have given results 
 so consistent that the author feels that they are conclusive. 
 
 This softening and hardening of enamel has a very practical 
 bearing in relation to mouth cleansing and the use of brush and 
 dentifrices. Enamel that in its hardest state would only show 
 insignificant wear to dentifrice may, in a softened state, lose a 
 very material amount of tooth structure. This softening and 
 hardening may readily account for the fact that some patients, 
 especially those fond of fruit, wear their teeth down at a com- 
 paratively early age. The mere friction of mastication is suf- 
 ficient to take off a layer of enamel softened by fruit or vinegar. 
 This seems to me a sufficient argument against mouth-washes 
 based on fruit acids or vinegar. I am convinced that enamel 
 
54 
 
 MODERN DENTISTRY 
 
 will harden and soften within certain Umits and that this harden- 
 ing and softening is influenced by the saliva and food-stuffs. 
 I also believe the same is true of dentin, but so far the tests 
 
 concerning this are not suffi- 
 ciently numerous to serve as 
 a basis for a positive asser- 
 tion. 
 
 Force Required in Masti- 
 cation. — The following experi- 
 ments were undertaken to 
 determine the amount of 
 triturating force required to 
 chew food, especially meat. 
 For the mastication tests a 
 natural skull with practically 
 perfect molars of average size 
 was cast in bronze. The 
 skull was so arranged that all 
 of the mastication was done 
 with two lower molars and 
 their occluding teeth. 
 
 The bronze skull was 
 clamped to a platform (Fig. 
 22,, A). B represents a cross- 
 bar under the jaws so ar- 
 ranged that the force applied 
 by the spring balance, C, 
 will be applied directly to the 
 first and second molars on the 
 left side of the j aw. The force 
 of mastication is then applied through the lever, D, and registered 
 by the needle, E. The skull is placed at such an angle to the 
 force that a triturating motion is given as the jaws come together. 
 F represents the handle by which the lower jaw can be guided 
 by the hand of the operator up to the time the actual force of 
 mastication is applied. The first experiments were with bread. 
 Dry, crisp crusts broke at 15 pounds pressure; but a mixture of 
 
 Fig. 23. — Machine for measuring the 
 force required for mastication. (Author's 
 instrument.) 
 
A STUDY OF TOOTH ENAMEL AND SALIVA 55 
 
 soft inside and crust, such as we ordinarily find, could not be 
 bitten through with a force of loo pounds. The crust and in- 
 side formed a dense immovable mass, but when a Httle saliva 
 was placed on this same mass, it was readily masticated with a 
 force of 3 pounds. Asparagus, roast onion, peas, and roast 
 potato were chewed with i to 2 pounds pressure. Raw cabbage 
 required a pressure of 16 pounds; raw onion, 4 pounds; head 
 lettuce, 8 pounds; whole radishes broke at from 20 to 25 
 pounds, while pieces broke at from 10 to 15 pounds. 
 
 This gives a fair idea what triturating force is required for 
 the mastication of vegetables. 
 
 Following is a table of the triturating forces necessary to 
 masticate meat: 
 
 Pounds 
 
 Corned beef 18 to 22 
 
 Boiled beef 3 
 
 Tongue i to 2 
 
 Lamb chop 16 to 20 
 
 Roast lamb 4 
 
 Roast lamb kidney 3 
 
 Tenderloin of beefsteak, very tender 8 to 9 
 
 Sirloin steak 10, 20, 43 
 
 Beef, bottom of round, tough 38 to 42 
 
 Roast beef 20 to 35 
 
 Boiled ham 10 to 14 
 
 Broiled ham i o to 13 
 
 Pork chops 25 to 30 
 
 Roast veal 16 
 
 Veal chops 12 
 
 Roast mutton 18 to 22 
 
 Dr. Black's tests have shown that the human jaws can exert 
 a pressure of from 150 to 300 pounds. I show here a man biting 
 340 pounds on a gnathodynamometer (Fig. 24). The force 
 reqmred to crack a hazel or pecan nut, such as the ordinary 
 urchin breaks with ease, is 100 to 230 pounds. These tests, of 
 course, are not recommended unless the teeth are exceptionally 
 strong and the sockets absolutely healthy, for if the teeth are 
 sensitive to pressure the jaws will instinctively avoid their full 
 force. It is, therefore, clear that thorough mastication and hence 
 proper digestion of the food is only possible when the teeth are 
 
56 
 
 MODERN DENTISTRY 
 
 sound and the gums free from infection; and such a condition 
 of the teeth and gums can only be maintained through scientific 
 mouth hygiene. 
 
 Dentifrices and Mouth-washes. — As stated in Chapter II, 
 mechanical cleansing of the bacterial masses will reduce the germs 
 to an insignificant number and it will also cause an auto-inocula- 
 tion by rubbing the infection into the tissues, thus stimulating 
 them to form protective bacterial ferments. The ferments thus 
 formed are so effective in restoring inflamed tissues to health 
 
 Fig. 24. — Gnathodynamometer for measuring the force exerted by the closing of 
 the jaws. This represents a man biting 340 pounds — over twice his weight. 
 
 that all other means for combating the invading infection sink 
 into secondary importance. Thus the blood-serum thoroughly 
 charged with protective antibodies might justly be termed the 
 most effective mouth- wash at our disposal; for this mouth-wash 
 by its very nature is most readily appHed to the invading hosts 
 even when they have penetrated deeply below the surface of the 
 mucous membrane. 
 
 And yet there are certain mouth-washes and antiseptic 
 dentifrices that can be used to effectively supplement the pro- 
 
A STUDY OF TOOTH ENAMEL AND SALIVA 57 
 
 tective elements of the blood, but they must be considered purely 
 supplementary in their action. Any chemical mouth-wash 
 sufficiently strong to kill bacterial masses in the time permitted 
 for its apphcation in the mouth must be strong enough to be 
 poisonous to the tissues, and such a result is apt to weaken the 
 resistance of the tissue cells against further bacterial attacks. 
 Effective mouth-washes and antiseptic dentifrices should co- 
 operate with the curative action of the tissue cells without 
 weakening them. 
 
 Heretofore this important principle underlying the use of 
 antiseptics has not been sufficiently understood. Strong anti- 
 septics, as washes, have been used without the prehminary 
 mechanical removal of the bacterial masses in the vain expecta- 
 tion that the strong germicidal wash would be able to destroy 
 and wash the adhesive colonies away. Under these conditions 
 the exterior portions of the sticky masses of germs alone are killed, 
 leaving the infection unharmed beneath the surface of the bac- 
 terial plaque to continue its attacks on the tissues with which 
 it is in contact. And the rest of the mucous membrane of the 
 mouth, which was not covered by the bacterial plaques, continues 
 to have its bacterial resistance lowered by the use of the strong 
 antiseptic, and is rendered more Hkely to accept infection after 
 the protective action of the strong antiseptic has been dissipated 
 by the oral fluids. 
 
 In addition to the bactericidal action of the blood there are 
 at least three health-restoring processes in the mouth. First, 
 a substance that is present for the specific purpose of special 
 protection, which is illustrated by the saliva's power of retarding 
 enamel decalcification; the second consists of an automatic 
 power of resistance and self-repair, which is illustrated by the 
 power possessed by tooth enamel to reharden after partial 
 decalcification by acids; third, its power to reharden the surface 
 when its soft under substance is exposed by attrition to the 
 saliva or air. 
 
 Salivas have different protective properties, and the saliva in 
 the same mouth will show a great variation in its preservative 
 power under various conditions of the system. It is possible that 
 
58 MODERN DENTISTRY 
 
 gout, diabetes, tuberculosis, arteriosclerosis, or even a bad attack 
 of grip, may reduce the vitality of the agencies resisting enamel 
 deterioration. 
 
 It will be noted by the careful observer that many mouth- 
 washes, such as solutions of chlorate of potash, peroxid of hydro- 
 gen, and sodium silicofluorid, have wonderfully healing prop- 
 erties in the mouth, and yet in the dilutions used in the mouth 
 they have not apparently any marked germicidal action. Thus 
 we have had up to the present time a supposedly irreconcilable 
 difference between cHnical experience and laboratory research. 
 But fortunately the wonderful researches of Ehrlich^ concerning 
 the germicidal action of salvarsan have thrown light on this 
 most important subject. EhrHch found that the syphilis germs 
 exposed to the action of salvarsan were neither destroyed nor 
 rendered in any way different as regards appearance or activity, 
 but that they were nevertheless sensitized, so that the white 
 corpuscles of the blood could eat them in a way impossible to 
 syphilis germs that had not been subjected to the action of sal- 
 varsan. He then formulated the principle that germs might 
 be sensitized by a comparatively inert drug, so that the bacterial 
 action of the tissues or blood might digest them. The effective 
 non-germicidal agents, such as chlorate of potash, peroxid of 
 hydrogen, and sodium silicofluorid, probably act on this principle. 
 
 Recent experiments under the supervision of Dr. A. P. 
 Kitchens indicate that a i per cent, peroxid solution has the same 
 strength in inhibiting the growth of typhoid bacilli as a i per 
 cent, carbolic acid solution. This action, while non-germicidal, 
 is a valuable scientific fact, and is particularly interesting in 
 reference to the antiseptic action of certain oxygen-Kberating 
 dentifrices which claim to cleanse the mouth by the development 
 of hydrogen peroxid. The idea is so excellent that it should be 
 given encouragement by both pharmacists and the public at 
 large, but as yet none of the widely exploited peroxid-forming 
 dentifrices, according to the analyses that have come to my 
 notice, have ever been able to develop more than 0.5 per cent, 
 free oxygen. This, as can be shown mathematically, cannot 
 iThe Lancet, August 16, 1913. 
 
A STUDY OF TOOTH ENAMEL AND SALIVA 59 
 
 form more than 35 minims of the standard 3 per cent, peroxid 
 solution for each 100 grains of dentifrice. The amount of 
 tooth-powder capable of being put on an average tooth-brush 
 is seldom as much as 10 grains, which 10 grains or less of powder 
 would have to be depended upon to deliver the antiseptic action 
 to the mouth. These 10 grains of tooth-powder, under the most 
 favorable conditions, would then deliver 3I drops of the ofi&cial 
 peroxid solution, no more; 3I drops or even 5 drops would be 
 palpably inadequate to have any effect in the mouth. Some 
 of these preparations that have been claimed to have the power 
 of sterilization by free oxygen, under analysis did not show the 
 presence of free oxygen at all. This was due to some error in 
 the manufacture, no doubt, but for practical antisepsis in the 
 mouth it really made little difference, as 3 drops of peroxid 
 of hydrogen would be so rapidly diluted and broken up by the 
 oral fluids that its antiseptic value in the course of half a minute 
 could be hardly much more effective than so much distilled water. 
 Peroxid of calcium and peroxid of strontium, as recommended 
 by many writers, are entirely too caustic to be used pure in the 
 mouth. When placed in any quantity on the tongue they make 
 a bad burn that lasts for days. However, the commercial prep- 
 aration of peroxid of magnesium is especially bland and effec- 
 tive. It comes diluted with magnesium hydroxid and carbonate, 
 so that it variously yields from 4 to 7 per cent, free oxygen, and 
 is only soluble in about 15,000 parts of water — practically in- 
 soluble. This powder can be freely taken into the mouth in 
 any quantity, hberating for every 100 grains enough oxygen 
 to make 280 to 500 drops of a 3 per cent, alkaline peroxid solu- 
 tion. The commercial powder has just about the cutting grit 
 of precipitated chalk, and when finely powdered, practically 
 none at all. When it is evacuated from the mouth large quanti- 
 ties adhere to the interstices and necks of the teeth. This 
 tendency may be turned to great advantage by the patient, for 
 while this powder is practically insoluble in water, it is readily 
 converted into a soluble magnesium salt by any acid that may 
 chance to be present. Perborate of soda, as will be shown 
 shortly, has no grit at all. 
 
6o MODERN DENTISTRY 
 
 But now let us discuss the question of abrasives in denti- 
 frices. AH thoughtful dentists must have noticed that there 
 is a terrible loss of enamel in the mouths of those who are par- 
 ticularly careful of their teeth, and this appears generally be- 
 tween the ages of forty and fifty and is made manifest by the 
 complete disappearance of the enamel in ever-spreading foci 
 on the labial surfaces of the front teeth. This has been explained 
 by many as arising from gout, rheumatism, the absence of the 
 sulphocyanates in the sahva or an excess of acid calcium phos- 
 phate. A systemic cause may be partly responsible for this 
 condition, but the author does not know of a single case of such 
 erosion in the mouth of a patient who did not use tooth-powder 
 excessively and who was not abnormally fond of acid fruits. 
 As the loss of the enamel is confined almost entirely to incisors, 
 canines, bicuspids, and first molars, it would seem strange that 
 a disease wholly systemic should not attack all of the teeth of 
 the mouth with equal impartiality. 
 
 Destructive Action of Dentifrices. — In 1908 I pubHshed in 
 the Dental Brief experiments showing the effect of grits on the 
 teeth, proving that tooth-powders, even of chalk, were largely 
 instrumental in cutting the well-known smooth grooves in the 
 necks of teeth, that so frequently appear from second molar to 
 second molar. These characteristic grooves were readily re- 
 produced on extracted teeth out of the mouth. At that time , from 
 experiments made with a brush- wheel and pumice, I erroneously 
 thought that grits had no effect on the enamel of the grinding 
 surfaces. Although these tests were judged only from their 
 macroscopic effect, and no measuring instrument of precision 
 was used, and although they were faulty, inasmuch as they did 
 not reveal the full extent and significance of the destructive action 
 of pumice, chalk, etc., they were the beginning of my investiga- 
 tions in this field. Later on a series of experiments was under- 
 taken to determine just what would happen to the enamel and 
 cementum of a tooth when brushed with an ordinary tooth- 
 brush and saliva; when brushed with certain mouth-washes; 
 when brushed with certain proprietary dentifrices; and finally, 
 what happened when brushed with plain precipitated chalk. 
 
A STUDY or TOOTH ENAMEL AND SALIVA 6 1 
 
 In each instance the loss of tooth substance was carefully deter- 
 mined by an especially constructed Brown & Sharpe micrometer. 
 The first test was made to determine the effect of brushing 
 the enamel and cementum for ten minutes with a new brush 
 and saliva alone. Many such tests showed that the brush and 
 saliva seemed to have no harmful effect on cementum or enamel. 
 Six of the most prominent and best advertised dentifrices were 
 then tested, a new brush being used with saliva and dentifrice 
 for each test, the brushing being continued for ten minutes: 
 Dentifrice No. i cut off o.oooi inch of enamel and from 
 0.0023 to 0.0083 i^^ch of cementum. 
 
 Dentifrice No. 2 gave a loss of 0.0001 inch of enamel and 
 0.0026 inch of cementum. 
 
 Dentifrice No. 3 gave no loss of enamel and a loss of 0.0066 
 inch of cementum. 
 
 Dentifrice No. 4 gave a barely measurable loss of enamel and 
 0.012 1 inch of cementum. 
 
 Dentifrice No. 5 caused no loss of enamel and 0.0073 i^^ch of 
 cementum. 
 
 Dentifrice No. 6 caused no loss of enamel and 0.0007 i^ch of 
 cementum. 
 
 The only reason the powders with grit are so popular, in my 
 opinion, is because they make the front teeth presentable with 
 a minimum amount of labor. The unsatisfactory results are 
 partly due to laziness and partly due to the inefficient, un- 
 scientific teaching of the profession, who have recommended 
 methods of tooth-brushirtg that a simple inspection of the 
 mouth will show do not cleanse the teeth. 
 
 Having investigated some of the prominent proprietary 
 dentifrices, I next applied the same tests to the standard chemical 
 substances that might prove of value in mouth prophylaxis. 
 I found, as would be expected, that ordinary chalk would cut 
 the cementum and enamel. Thinking there might be an excess 
 of sihca in it, precipitated chalk, guaranteed to be free from silica, 
 was procured from a standard chemical company. It seemed 
 to cut more than the others. The abrasive action of peroxid 
 of magnesium was next tried and it was found that in its coarse 
 
62 MODERN DENTISTRY 
 
 state it had a friction grit on the enamel and cementum some- 
 what less active than precipitated chalk, but nevertheless a 
 decided grit. When, however, the peroxid of magnesium was 
 ground in an agate mortar to impalpabihty no such erosion was 
 attained, thus showing that in peroxid of magnesium we can have 
 a grit slightly less than chalk down to almost no grit at all, and 
 also a tooth-powder that will give abundant oxygen. I next 
 tried the frictional action of perborate of sodium mixed with 
 saHva on a tooth, and found that there was no erosive action 
 that could be detected by the Brown & Sharpe micrometer. 
 This was particularly gratifying, as perborate of sodium is a 
 bland salt that can be freely placed in the mouth without caustic 
 action; it liberates 9 to 10 per cent, of oxygen, and in the presence 
 of any acid that may be present forms a strong alkaline peroxid 
 solution. 
 
 Therefore, when there are any grooves on the front teeth the 
 author forbids the use of grit dentifrices and recommends the 
 use of perborate of soda alone; and when patients have been 
 carefully instructed in the proper way of brushing their teeth, 
 perborate of soda seems quite able to keep the teeth clean. For 
 patients that have healthy gums, with no tendency to gum re- 
 cession or thinning of the enamel, the following formula may 
 be used: 
 
 Peroxid of magnesium (sieve 200 fine) 60 parts. 
 
 Perborate of sodium 30 " 
 
 Pulv. saponis. 10 " 
 
 Flavoring to suit. 
 
 When an extracted tooth was brushed for ten minutes with 
 this powder no loss of enamel occurred and a barely measurable 
 loss of cementum. 
 
 Three specimens of chalk were also tested : The first sample 
 was made by precipitation in 50 liters of water with slow precipita- 
 tion. The second was made by quick precipitation in a strongly 
 concentrated solution. The slow precipitate, as would be ex- 
 pected, gave a larger crystal than the quick precipitate. The 
 larger crystals of the first specimen varied from 17 to 5.6 microns 
 
A STUDY OF TOOTH ENAMEL AND SALIVA 63 
 
 in diameter; the smaller crystals of the second specimen meas- 
 ured from 4 to 2 microns in diameter. The third specimen was 
 composed of precipitated chalk very finely ground, and yet 
 these three specimens seemed about equally destructive of 
 enamel and cementum. This would indicate that it is the chalk 
 itself, not the preparation, that is responsible for its destructive 
 action. 
 
 Specimens of silicious earth, precipitated phosphate of cal- 
 cium, precipitated carbonate of calcium, and calcined magnesium 
 (light) were tested for their erosive action, as the table of tests 
 will show. In these erosion tests a tooth-brush charged with 
 saliva and various grits was swept by hand over a natural tooth 
 for ten minutes. Saliva from the same mouth was used through- 
 out all the tests: 
 
 Number of Loss of enamel Loss of cementum 
 
 minutes. o.oooi inch. o.oooi inch. 
 
 Dentifrice i 10 i 26 
 
 Dentifrice 2 10 i 83 
 
 Dentifrice 3 10 o 66 
 
 Dentifrice 4 10 a trace 121 
 
 Dentifrice 5 10 o 73 
 
 Dentifrice 6 10 o 7 
 
 Dentifrice, Dr. X 10 i ^^ 
 
 Dentifrice, Dr. Head (old formula) 10 i 20 
 
 Various kinds of precipitated chalk 10 1-3 8-18-28 
 
 Magnesium carbonate (precipitated) 10 o 19 
 
 Precipitated calcium phosphate 10 i 36 
 
 Tooth brushed with saliva alone 10 o o 
 
 Magnesia, calcined 10 1-3 27 
 
 Perborate of soda 10 o o 
 
 Dr. Head's new formula 10 o 3-9 
 
 Very fine peroxid of magnesia 10 o o 
 
 Saturated solution of sodimn silicofluorid. . . 10 o o 
 
 Hexamethylenamin 10 i i 
 
 Summary.— In closing this chapter let us briefly go over 
 some of the points that might properly be emphasized. Tooth- 
 powders containing grits are harmful to both enamel and ce- 
 mentum, and the patients should be taught to brush and cleanse 
 the teeth without their aid. AU stains that cannot be removed 
 without the aid of tooth-cutting grit should be removed only 
 by the dentist. Moreover, the patient should be trained so 
 
64 MODERN DENTISTRY 
 
 thoroughly in the use of the brush and floss-silk that dentifrices 
 and mouth-washes will be of minor importance. Very finely 
 powdered peroxid of magnesium, with lo per cent, of soap and 
 a suitable flavoring agent, makes a valuable antiseptic peroxid 
 powder, and when left around the teeth at night it will prove an 
 invaluable antacid. For those who do not wish a semblance of 
 grit in their powder, flavored perborate of soda can be used 
 both on the brush and also, in lo-grain tablet form, as valuable 
 mouth-wash tablets. 
 
 A I per cent, peroxid of hydrogen wash held in the mouth for 
 two or more minutes will reduce inflammation rapidly and quickly. 
 A saturated solution in water of sodium sihcofluorid is also ordi- 
 narily useful. It forms a 0.61 per cent solution. This may be 
 held in the mouth from two to five minutes, three times a day, 
 by patients under treatment for pyorrhea. While in some few 
 cases it causes a brown precipitate on the teeth which, however, 
 is easily removable, in every case its healing effect on the inflamed 
 gums is so satisfactory as to be little less than marvelous. It is 
 non-poisonous and cheap, being readily purchased c. p. at 75 
 cents a pound, which is enough to make almost a barrel of 
 mouth-wash. And, above all, being a fluorid, it has the fluorid 
 antiseptic qualities without the usual resultant erosive action 
 on the procelain crowns or fillings. 
 
CHAPTER IV 
 
 TREATMENT OF MOUTH INFECTION 
 
 General Diagnosis.^ — In determining the causes of mouth 
 infection it is of utmost importance that a comprehensive study- 
 should be made of the entire body to determine the presence 
 of associated disease. And here is where the sympathetic, 
 scientific co-operation between the general practitioner and the 
 dentist is of the utmost importance. Purely local infections can 
 be treated and cured by local treatment, but where the mouth 
 infection has spread to other organs of the body, such as the 
 stomach, intestines, genito-urinary tract, etc., secondary infection 
 occurs which weakens the bacterial resistance of the blood and 
 causes the original infection to reappear in the mouth, even 
 though it had temporarily yielded to local treatment. Normal 
 blood has a certain germicidal power that will ordinarily resist 
 bacterial invasion. But if the bacterial invasion becomes 
 intrenched both in position and number, and lowers the resistance 
 of the blood, it is evident that the first step in the restoration of 
 the blood to its normal germicidal power is to first remove the 
 depot of infection that is the primary cause of blood poverty. 
 
 The mouth has long been considered a sort of health ba- 
 rometer of the general body. It is now recognized not only as 
 a gage of the general systemic health, but also as one of the 
 principal sources of primary infection that may spread general 
 disease. This, by reacting on the body vigor, may increase 
 the mouth infection, which will, by its increased reaction, cause 
 a still greater lowering of the general vitahty. In fact, mouth 
 infection in its relation to the whole body might be likened to 
 a vicious poHtical gang in its relation to the state. The gang 
 captures the city organization through weakness or sluggishness 
 on the part of the voters, just as the infection makes its first in- 
 
 5 65 
 
66 MODERN DENTISTRY 
 
 road into the tissues. Being intrenched in the city government, 
 the gang poisons the minds and lowers the moral resistance 
 of influential citizens by concessions and special privileges 
 that make them dependent on the gang for their subsistence. 
 Similarly, the once healthy tissues finally endure bacterial in- 
 vasion in the form of chronic infection, which from that time 
 on pours its toxins into the blood stream, causing degeneration 
 of the vital organs, any one of which may then become a new 
 depot of infection, sending out poisons that strengthen the power 
 and position of the original bacterial gangsters. And just as at 
 the start the ehmination of the original infection or gang would 
 have prevented the general infection, so when the infection 
 becomes general and is composed of a number of individual 
 gangs or depots of infection, every one of these infecting depots 
 must be removed before the body or state can be considered 
 sound, for each one of the depots can spread and become general 
 I'ust as the first depot of infection spread. 
 
 Thus, mouth infection cannot be considered from a purely 
 local point of view, but must be treated both as a symptom and 
 a cause. Where it is pronounced, and the teeth and gums show 
 general advanced deterioration, the general practitioner should 
 go over the heart, lungs, liver, spleen, kidneys, etc., with special 
 care, and the general body weight should be carefully noted. 
 In fact, no means of investigating the body for depots of infection 
 should be neglected. Any tuberculous, syphilitic, or gonorrheal 
 taint should be treated as a matter of vital importance. The 
 eye, ear, nose, throat, and especially the tonsils should be ex- 
 amined, and if found infected, should all be treated, thus eliminat- 
 ing them as possible depots of infection. This does not mean 
 that ten or twenty doctors will have to be working on one poor 
 patient at the same time. Ordinarily the co-operation of a 
 general practitioner will be all that is necessary. 
 
 Many physicians are laboring under the mistaken idea that 
 the mere extraction of infected teeth will be sufficient to remove 
 the full effects of the infection. Such extraction will effect a 
 cure only while the infection is purely local, but as the infection 
 may have spread to other parts of the body through bacterial 
 
TREATMENT OF MOUTH INFECTION 67 
 
 migration, the extraction of an infected tooth may be as bene- 
 ficial as locking the stable door after the horse has been stolen. 
 Such extraction without a judicious bacterial examination may 
 actually do harm, since it will take away the opportunity of 
 following the infection in its migration through the body and 
 ehminating it by an autogenous vaccine made from the original 
 source of infection. 
 
 The urine should be carefully examined, with special reference 
 to the presence of albumin, sugar, casts, and indican. Indican 
 is frequently present as a systemic association of mouth infec- 
 tion, and its disappearance is noted as the treatment progresses 
 to a successful termination. A careful and complete blood- 
 count should always be made. The intensity of the hemoglobin 
 and the number of the red corpuscles should be noted. The 
 white blood-corpuscles should be especially observed to see if 
 any leukocytosis is present. The differential white blood-cor- 
 puscle count should be also made with a view to seeing whether 
 there is any marked lymphocytosis, as this would caution us 
 to look for inflammatory lymphatic enlargement during the 
 treatment. The joints should be examined for gouty deposits 
 and crepitation. This especially applies to the knee-joints. 
 The glands of the axillae and neck should be examined for enlarge- 
 ment. In a woman the breasts should be examined for hard 
 lumps or indurations, as these will have a special lowering 
 effect upon the system and should receive surgical attention, 
 if necessary. In fact, a dentist in treating mouth infection is 
 like a countryman at a fair who buys a pair of gloves with the 
 privilege of taking a grab in the grab-bag. The dentist knows 
 he is going to treat and probably cure the mouth infection, but 
 he does not know what other disease he is going to unearth and 
 cure with the aid of the general practitioner. It therefore is 
 wise to have a general diagnosis made on as broad Hnes as possible, 
 so as to note the general systemic improvement as the mouth 
 infection disappears, and to make it possible to give a more ac- 
 curate promise in regard to the permanence of the cure. 
 
 Local Diagnosis. — Having laid down in a general way the 
 lines of investigation that should be followed in the physical 
 
68 MODERN DENTISTRY 
 
 examination and the laboratory, let us discuss what measures 
 should be taken in the local diagnosis of the disease in the mouth. 
 All inflamed spots should be noted and each tooth should be tested 
 between the fingers for looseness. Then a fine probe should 
 be passed around the necks of all the teeth, searching for pockets 
 of infection, for these are not by any means always associated 
 with redness or inflammation. Where there is an old chronic 
 infection around a root there may be no redness or soreness. 
 In an adult, where the instrument goes under the gum for a dis- 
 tance of I inch, peridental deterioration is indicated; and where 
 the probe will penetrate between the root and the bony socket 
 for I inch or more a pyorrhea pocket of infection is surely 
 present and should be so considered and treated. When the 
 pocket of infection extends so far along the root as to approach 
 the tip, it must not be forgotten that the pulp within the tooth 
 has undoubtedly become infected and that the pocket cannot 
 be healed until the pulp within the tooth has been removed, and 
 the nerve canal or canals sterilized and filled antiseptically. 
 Special care should be given to the spaces between the teeth, as 
 the pockets of infection usually start in such places. 
 
 Having carefully examined the gums for pockets and open 
 fistulse, the condition of the pulps of the teeth should next be 
 investigated, because a living pulp infected either by a cavity of 
 decay, filled or unfilled, or by gum infection along the root, may 
 be a serious depot of general infection. As before stated, an 
 infected living pulp will hinder if not prevent the healing of the 
 inflamed gum around it, so long as it is in a position to pour out 
 its insidious stream of infection through the tip of the root. 
 Infected pulps are either oversensitive or undersensitive to the 
 apphcation of heat. If the infection has, as one might say, 
 exasperated an inflamed tissue, the tooth will be excessively 
 sensitive to heat to such an extent as to cause a flash of pain that 
 will extend over the entire side of the face. If, however, the 
 infection has progressed so far that the pulp is d3dng or nearly 
 dead, heat will cause Httle or no reaction. The instrument for 
 such diagnosis consists of an electric cautery heated to the 
 point of just turning paper black (Fig. 25). This electric 
 
TREATMENT OF MOUTH INFECTION 69 
 
 cautery can be kept at an even temperature and, therefore, 
 the same amount of stimulation will follow its application to the 
 teeth during a given period. Thus the relative irritabihty of 
 the pulps can be readily ascertained, which palpably would 
 not be possible with a steel instrument heated in the gas flame. 
 Having, then, heated the electric cautery just to the point of 
 turning paper black, it should be applied to the neck of each tooth 
 for a second at a time. If the consequent pain immediately 
 disappears, the pulp is probably normal, but if the pain does not 
 disappear for three or four seconds, infection of the pulp is 
 indicated; and if a flash of pain extends over the face, causing a 
 lasting neuralgic thrill, the pulp is seriously infected and should 
 
 Fig. 25. — Electric cautery used in diagnosing the condition of the dental pulp. 
 
 (Cut f actual size.) 
 
 be removed at once. Where no reaction at all is obtained and 
 the tooth shows no signs of the pulp having been removed and 
 the canals previously filled, the tooth should unquestionably 
 be opened and the canals sterilized and filled, because clinical 
 experience has proved that in such a case the pulp is usually 
 dead and putrescent and may be the cause at any time of \dolent 
 organic infection. Teeth with dead pulps may be associated 
 with pain during the process of mastication or may be especially 
 sensitive to a sharp rap on the masticating surface, a condition 
 which exists when the irritating infection is acute. But when in 
 the course of time the inflammation has become chronic, the tooth 
 may appear almost normal and the electric cautery is the best 
 diagnostic instrument for detecting the true condition by 
 demonstrating an absence of response to heat. It must, however, 
 
70 MODERN DENTISTRY 
 
 be remembered that some teeth are normally insensitive to heat, 
 while others are supersensitive, this being a systemic condition 
 of the nerves in general. Therefore, variations from the normal 
 response should be regarded as significant of possible pathologic 
 irritation and infection. It also must be remembered that the 
 molars ordinarily respond to changes of temperature much less 
 than central incisors or canines, owing to the difference in the 
 amount of tooth structure the heat has to travel before reaching 
 the pulp. Therefore if a molar and canine respond equally 
 under stimulation, it will indicate that the molar is oversensitive 
 or the canine less sensitive than normal. When a general lack 
 of response to heat is noted, unaccompanied by inflammation 
 in the gums surrounding the teeth, we should always bear in 
 mind that this may be due to a normal atrophy of the pulps, 
 unaccompanied by infection. In such a case, unless there is 
 
 Fig. 26. — Automatic hammer, formerly used for inserting gold fillings, now most 
 effective in testing relative sensibility of teeth to the force of percussion. 
 
 a systemic depression indicating a masked depot of infection, such 
 teeth should be left undisturbed. If, however, applications of 
 the cautery cause an extraordinary flash of pain in any one tooth, 
 lasting for several seconds, the pulp should be removed and the 
 canals filled. The instrument for testing sensibility under per- 
 cussion is the automatic hammer that will give a blow of from 
 4 to 6 pounds (Fig. 26). The old plugger used for malleting gold 
 will serve this purpose admirably. Each tooth should be tested 
 with this hammer on the grinding surface for sensibility at the 
 tips of the roots, for, as just stated, where infection has been forced 
 into the gums, such a blow will be associated with much pain un- 
 less the inflammation has become chronic. It is astonishing how 
 these tests for excessive mobility, exploration for pockets and 
 fistulte, reaction to heat, and reaction to a blow or pressure will 
 corroborate one another. Where a tooth shows excessive 
 mobility, and the pulp is infected to the point of inflammation, 
 
TREATMENT OF MOUTH INFECTION 
 
 71 
 
 there will be a sharp reaction to heat, and usually it will be as- 
 sociated with a pus pocket in the gum, and frequently will be 
 sore to pressure. Also where there is excessive mobility the 
 tooth may or may not be associated with a pus pocket, there 
 may be no reaction to heat, and it may or may not be sensitive 
 to pressure, showing a state of more or less chronic infection that 
 is none the less dangerous because it is masked. 
 
 Fig. 27. — Dry-cell battery, supplied with a milliammeter, used in diagnosis and 
 treatment of blind abscesses. Various terminals are shown. 
 
 Electrolysis Test. — There is another test that is occasionally 
 valuable in diagnosing the presence of a blind abscess under the 
 gum, namely, the ionization test with the direct current of an 
 electric battery (Fig. 27). The direct current of a series of dry 
 cells is used. The positive pole is placed in the hand of the patient 
 in the form of a large wet sponge. The negative pole, in the form 
 of a small German-silver electrode, the sides protected by rubber. 
 
72 MODERN DENTISTRY 
 
 is then swept back and forth over the infected areas, with the 
 current turned on until it reaches i or i| milHamperes. 
 
 Four or five dry cells are usually enough to give such a current, 
 but it is better to have i6 in all, to allow for deterioration. 
 When the negative pole has been swept across the gum for a 
 minute or so, a white froth begins to come through the gum, that 
 looks something like pus, but is not pus as it can be obtained 
 from healthy tissue as well as from inflamed tissue, the only 
 difference being that in healthy tissue a stronger current is re- 
 quired. This froth can come through the gum without causing 
 any wound or erosion, and its extraction from an inflamed gum 
 has special therapeutic value. When i^ to i dram of this frothy 
 serum has been obtained the pain and irritation of the tissue 
 treated will disappear in a manner almost magical, and in a day 
 or two the tissue will usually be found to have healed. This 
 instrument skilfully used for an hour or more will even abort 
 an acute alveolar abscess. As a test for the presence of a blind 
 fistula the negative pole is swept over the inflamed tissue and the 
 frothy serum is extracted as previously described. If there is a 
 blind fistula near the surface, a red spot will suddenly appear on 
 the gum and the fistula will be actually drawn to the surface. 
 The rest of the gum region being wiped dry will appear unchanged, 
 except that it will be less inflamed and engorged. 
 
 A possible though probably incomplete explanation of this 
 phenomenon is as follows: The large positive pole distributes 
 and weakens the intensity of the current to such an extent that 
 there is practically no local therapeutic action. But the current 
 at the negative pole is concentrated, and there the blood-serum 
 is broken up by the ionization into the positive and negative 
 ions — since the positive pole of a battery attracts the negative 
 ions, and the negative pole, the positive ions. The negative pole 
 of the battery extracts these positive ions, leaving the negative 
 ions free within the tissues. A large proportion of the substance 
 of the blood-serum is water, which is composed of hydrogen 
 (positive) and oxygen (negative), and thus the negative pole 
 in extracting frothy serum most probably extracts the positive 
 hydrogen from the water of the serum and leaves within the tis- 
 
TREATMENT OF MOUTH INFECTION 73 
 
 sues nascent oxygen which has long been recognized as a powerful 
 germicide and stimulator of cell growth. Just how the oxygen 
 stimulates the cell growth or acts as a germicide may not be 
 quite clear, but just as we know that it is necessary for the oxygen 
 entering the lungs to permeate all the tissues of the body, if the 
 body is to develop and grow, so it is not unreasonable to suppose 
 that by the electric battery appKed in this manner we have made 
 a sort of local respiration and have produced locally on tissues 
 of reduced vitality the same stimulation that the oxygen from the 
 lungs is producing generally throughout the body. This theory 
 does not take into account the possibly important action of 
 the other negative ions that are set free with the oxygen, the action 
 of which may also have great therapeutic value. 
 
 So, basing the theory of this therapeutic phenomenon on the 
 stimulating action of nascent oxygen set free in the tissues, 
 which theory is admittedly incomplete, the following would be 
 a possible explanation: Inflammatory gum tissue contains more 
 fluid than the normal tissue, and therefore is perhaps a better 
 conductor of electricity. Where there is the greatest current 
 there will naturally be the greatest cell disintegration, and there- 
 fore where there is a blind abscess hidden under the gum there 
 will be a natural path for the electric current which will con- 
 centrate on that spot and break down the overlying tissues so 
 as to reveal the path of the fistula hidden beneath. When this 
 hidden fistula is revealed, it can be opened and treated sur- 
 gically. The x-ray photograph, as will be shown later, is a 
 valuable guide in diagnosing the conditions of the hard tissues, 
 but it gives very little idea of the inflammatory state of the soft 
 tissues covering the bone, and this ionization test will frequently 
 reveal conditions hidden beneath the mucous membrane that 
 could be revealed in no other way. 
 
 This therapeutic phenomenon, as shown by the direct electric 
 current, was brought to the attention of a dental society some 
 fifteen years ago by a man who claimed that he could cure a boil 
 by the application of the current as just described. He even 
 claimed that he could draw pus from a boil on one arm through 
 the body and out on the other arm. This preposterous claim 
 
74 MODERN DENTISTRY 
 
 caused him, metaphorically, to be laughed out of court, and he 
 made very little impression by his statements. However, there 
 were a few who were impressed by his evident sincerity, and they 
 found that while his explanation was wrong, and that he did not 
 extract pus, as he claimed, nevertheless his method did reduce 
 inflammation in an extraordinary degree. It is a matter of fact, 
 however, that this method as just described has been successfully 
 appHed to the cure of inflammatory tissue. 
 
 The violet-ray apparatus (Fig. 28) is also a great aid in the 
 diagnosis of the condition of the pulp within a tooth. The current 
 should be turned on until the spark will jump about | inch from 
 the electrode to the finger held near it as a test. The electrode 
 should then be placed upon the cutting edge or grinding surface 
 
 Fig. 28. — Violet-ray apparatus. 
 
 of the tooth to be tested. An interrupted current should then 
 be thrown on the tooth. This can be easily done by the operator 
 tapping the electrode with his finger. If the pulp is inflamed, 
 there will be an intense response; if the pulp is slightly alive, 
 there may be a response that would hardly be obtained by the 
 cautery; and if there is no response at all, it is wise not to be too 
 sure that the pulp is dead unless these tests are corroborated 
 by others. Unbroken tooth enamel sometimes offers complete 
 resistance to the violet-ray, but the exposed dentin ordinarily 
 accepts it readily. This test should always be used as a check to 
 the cautery test, which it supplements in an interesting w^ay. 
 Sometimes the application of the violet-ray will cause an active 
 stimulation to a tooth where the pulp is dead and a blind abscess 
 
TREATMENT OF MOUTH INFECTION 75 
 
 has formed at the tip of the root. This may be due to pressure 
 occasioned by liberation of gases from the fluids in the bony 
 cavity beyond the apical foramen. The application of the violet- 
 ray is also an excellent means of reducing general inflammation 
 of the mouth. 
 
 And last, and one of the most important means of diagnosis, 
 is the x-isiy, which will be dwelt upon at length in Chapter XII. 
 
 Local Treatment. — Having seen that the patient receives a 
 thorough general treatment in order that the depots of infection 
 may be removed from other parts of the body than the mouth, 
 it is then most essential that the dentist should see that no foci of 
 infection should be overlooked in the region over which he has 
 particular control. Every crown should be examined as a possible 
 depot of infection ; if the edges project into the gums and cannot 
 be smoothed so as to be non-irritating to the surrounding tissues, 
 the crown should be removed and replaced by one that will not 
 be a depot of infection. In fact, one of the easiest ways of tighten- 
 ing a loose root is ordinarily to remove a badly fitting crown. 
 This one act is frequently all that is necessary to effect a cure. 
 After the crown has been removed the inside of the root or tooth 
 should be carefully tested for infection within the canal. If the 
 pulp is alive, it should be tested with the cautery or violet-ray 
 electrode to see if it is sound, but as it usually happens in such 
 cases that the pulp is diseased or dead, the canal or canals should 
 be opened and properly cleansed and fiUed. And here it can be 
 stated that if there is no fistula, open or blind, at the end of a root 
 that has been properly fiUed, and if there is no pocket around such 
 a tooth, that tooth or root can be excluded absolutely as a source 
 of infection, and attention can confidently be turned to other 
 portions of the mouth. It is weU to emphasize this fact, since 
 many good serviceable roots and teeth have been ruthlessly 
 extracted at the order of the medical profession in a desire to 
 get rid of mouth infection; and while it is no doubt better that 
 five good teeth should be extracted rather than that one depot 
 of infection should remain in the mouth of a patient, it is never- 
 theless unfortunate that any good teeth should be sacrificed for 
 the lack of proper scientific diagnosis and treatment. 
 
76 MODERN DENTISTRY 
 
 But to continue in our surgical treatment of mouth infection. 
 What was said of crowns appKes even more to bridges that can- 
 not be cleansed between the bridge and the gums, and especially 
 around the supporting roots. No bridge should be inserted in 
 the m.outh that cannot be kept clean as the natural teeth, and 
 where this is impossible, and where the bands of the supporting 
 crowns project into the gums, forming ledges for infection, the 
 bridges should be removed and the supporting abutments 
 investigated, and, if necessary, treated. The non-cleansable 
 bridge should be replaced by a bridge that is natural in appear- 
 ance, effective for mastication, and capable of being cleansed as 
 thoroughly as any of the natural teeth. 
 
 Next, every tooth should be examined for cavities of decay, 
 and all the fillings in the teeth should be carefully examined for 
 .recurrence of decay. When a cavity of decay is found or re- 
 current decay is discovered under a filHng, all of the decayed 
 material should be thoroughly removed, and if the pulp is thereby 
 exposed, it should be anesthetized and removed, for it is incon- 
 ceivable that decay could reach the pulp without seriously in- 
 fecting it. It is true that such an exposed pulp may be capped 
 and preserved in a Hving state for years, but ordinarily the 
 extreme sensibihty of the tooth to thermal change or the steady 
 decrease in normal sensibility marks it as a source of possible 
 if not probable infection to the system at large. As long as in- 
 fection was not recognized as a source of systemic danger, the 
 preservation, by capping, of a pulp exposed by decay was de- 
 fensible, but in the Hght of our newer knowledge, it is indefen- 
 sible, and the time is not far distant when it will be called mal- 
 practice, for the pulp of a thoroughly developed tooth is not 
 essential to its vitality, appearance, or functions. The pulp is 
 the organ that forms the tooth-bone during its formative period, 
 but that period being over, it is exceedingly prone to deterioration 
 and infection. The real nourishment and maintenance of a tooth 
 come from the membrane supporting it in the tooth socket, and 
 as long as this membrane is healthy and free from infection there 
 is no fear but that the tooth will be able to perform all of its 
 proper functions. It is commonly believed that teeth deprived 
 
TREATMENT OF MOUTH INFECTION 77 
 
 of their pulps discolor. This is not necessarily so if the pulp is 
 thoroughly and antiseptically removed. Discolorations of the 
 teeth arise from putrefaction of the pulp within the tooth, which 
 becomes infiltrated with decaying matter. After the living pulp 
 has been removed the appUcation of a 4 per cent, formaldehyd 
 solution or any good albumin coagulant will prevent the breaking 
 down of the albumin of the tooth, and with proper filhng of the 
 canal no discoloration need be apprehended. When the decayed 
 spots in the teeth have been cut out and filled, the infected 
 pulps removed, and the infected canals sterilized and properly 
 filled, the dentist must not forget to examine the necks of the 
 teeth for filHngs with overhanging edges that may collect masses 
 of infection. Any such overhanging edges should be carefully 
 smoothed and polished with fissure burs, pohshed until the 
 necks of the teeth are beyond suspicion as collectors of bacterial 
 colonies. Next, the interdental spaces should be carefully ex- 
 amined to see if the approximation of the adjacent teeth is suflEi- 
 ciently accurate to prevent the food from being jammed down 
 on the gum between them during mastication. Such jamming 
 spikes the delicate gum on the underlying point of bone that 
 Hes between the teeth, and so starts an infection that, unre- 
 strained, will result in a pus-pocket along the sides of the root. 
 Restoration of the proper approximation of the sides of the teeth 
 is one of the prime means of curing invading infections of the 
 gums between the teeth. 
 
 It is also important to restore the normal occlusion of the 
 teeth. When a tooth has become inflamed in its socket, the 
 peridental membrane is apt to acquire a chronic thickening that 
 raises the tooth in its socket and leaves it permanently higher 
 than its neighbor. Thus, in its weakened condition it has to 
 stand the full force of mastication that should be borne by all 
 the teeth on that side of the face. The jaw can ordinarily develop 
 150 to 300 pounds pressure in the mastication of food, and this 
 weakened tooth while receiving such a shock cannot hope to 
 regain its normal tone. It takes what pressure it can, and then 
 by its painful protest warns its owner of its danger. The owner, 
 therefore, does not bite so hard, but favors it, and in so doing 
 
78 MODERN DENTISTRY 
 
 does not properly chew his food, and so another cause of sys- 
 temic deterioration is established. Therefore it is of primary 
 importance that all abnormalities of tooth occlusion should be 
 remedied, and if any tooth projects above its normal line it should 
 be cut down with an engine stone until the pressure of masti- 
 cation can be received equally by all the teeth. It is often worth 
 while to cut a sore tooth down below the normal bite so that it 
 can be given a complete rest until it regains its normal tone. 
 When a loose tooth can be advantageously saved it should be 
 splinted or fastened to an adjacent firm tooth, so that the act of 
 mastication will not bruise or twist it in the bony sockets of the 
 jaw. This can be done by t3dng them firmly to each other with 
 twisted silk twine, until the loose tooth yields to treatment and 
 becomes firm. Loose teeth that have become irregular should be 
 straightened before they are tightened by treatment, and the 
 straightening can usually be done by the twisted silk that is 
 
 C^ 4^ 
 
 Fig. 29. — Wire needle, No. 26 brass or gold wire, used for threading dental floss in 
 cleansing the interdental spaces. 
 
 splinting the teeth together. They can be permanently splinted 
 together when desirable, by means of platinum staples inserted 
 from the nerve canal of one tooth to the nerve canal of another, 
 the staples being set down in the substance of the tooth below 
 the line of mastication. When the tying or stapling is done care 
 should be taken, as before stated, to instruct the patient how to 
 cleanse the interdental spaces. Under such conditions this is 
 accomplished by the use of floss-silk threaded between the teeth 
 by a flexible wire needle (Fig. 29). The needle is made of gold 
 or brass wire, No. 26 gage, cut off to a length of 3 or 4 inches. 
 The end is bent over with a pair of pliers and soldered with soft 
 solder. 
 
 One of the prime necessities in examining a case of mouth 
 infection is a good series of a;-ray plates. Plates should be made 
 with a hard tube to show the conditions in the roots of the teeth, 
 and other plates should be made with the soft tube to diff eren- 
 
TREATMENT OF MOUTH INFECTION 79 
 
 tiate the softened areas in the alveolar process that the hard tube 
 does not clearly define. This is especially valuable when there 
 is systemic disturbance associated with nervous depression. In 
 the case of impacted teeth such a course of procedure is inval- 
 uable, as the hard tube will clearly show the condition of the tooth, 
 while the soft tube will give the condition of the surrounding 
 membrane and bony processes. Whenever impacted teeth are 
 found the impaction should be removed. And when all of these 
 points have been given due consideration we can hope to treat 
 the pockets of infection around the teeth with a fair prospect of 
 success. 
 
 The specific treatment of mouth infection will now be dis- 
 cussed. The pockets should be carefully explored for deposits 
 of tartar usually found upon the roots below the gums. The 
 removal of this tartar is absolutely essential for a cure, just as it 
 is necessary to remove a spHnter before the wound occasioned 
 by it will heal. So successful is this local treatment when carefully 
 performed that many dentists claim that it is the only procedure 
 necessary for a cure, unmindful of the fact that sometimes these 
 pockets around the teeth occur where no calcareous scale is 
 discoverable. Valuable and necessary as it is that the scale 
 should be thoroughly removed, such dentists sometimes burrow 
 so ruthlessly around the roots of teeth in their efforts to find 
 tartar that they do more harm than good, since their well-meant 
 efforts often result in ripping away much good tooth attachment 
 and occasion laceration of the blood-vessels at the tip of the roots, 
 causing the destruction of the pulps that otherwise might have 
 been saved. Thoroughness should always be commended, but 
 thoroughness that results in the loss of a tooth that more gentle 
 means could have saved is certainly ill-advised. Sets of instru- 
 ments have been devised for scaKng the roots of infected teeth 
 that are so compUcated and require such special knowledge that 
 their inventors peddle them around and persuade dentists to 
 loan them patients in order to demonstrate the efficacy of their 
 treatment, and these patients are charged large fees that are 
 divided between the instrument demonstrator and the dentist 
 providing the patient. This practice is certainly unprofessional 
 
8o 
 
 MODERN DENTISTRY 
 
 in its lack of frankness. A patient has every right to know to 
 whom he is paying his money, and any indirection on this subject 
 is apt to react upon the candor and honesty that is the funda- 
 mental basis of the professional relations of doctor and patient. 
 These dentists in claiming that local scraping will cure all pyor- 
 rhea pockets are obviously wrong, but careful curetting allevi- 
 ates so large a proportion of cases that by the laity their claims 
 seem substantiated. 
 
 ^=^^=5 
 
 Fig. 30. — Yunger scalers. 
 
 There are many simple and effective sets of instruments 
 made for scaling tartar. The Yunger instruments (Fig. 30) 
 have given excellent results, as also have the Logan-Buckley 
 instruments (Fig. 31) and Smith's (Fig. 32). As a matter of fact, 
 it is not the scalers that are so valuable as the man behind the 
 scaler. 
 
 Tartar Solvent. — Prior to 1900 there was nothing that would 
 soften tartar without softening the tooth as well. The agonies, 
 sometimes useless, that patients went through in having tartar 
 
TREATMENT OF MOUTH INFECTION 
 
 8i 
 
 removed from the roots of the teeth were unspeakable, and as 
 patient and dentist in this treatment, the author speaks feeHngly. 
 When, however, the author discovered, through a series of ex- 
 periments, that a 20 per cent, aqueous solution of hydrogen 
 ammonium fluorid with 10 per cent, free hydrofluoric acid would 
 
 Fig. 31. — Logan-Buckley scalers. 
 
 soften the bond between the tartar and tooth without harming 
 the tooth, the necessity for such heroic scraping passed away. 
 This mixture, according to tests made by Dr. A. P. Kitchens, 
 has a germicidal strength more than five times that of c. p. car- 
 bolic acid and, in addition to dissolving the tartar bond and 
 6 
 
82 
 
 MODERN DENTISTRY 
 
 minute calcareous scales, it also stimulates the reattachment 
 of the gum to the root. 
 
 Fig. 32. — Smith scalers. 
 
 The local treatment of the infected pockets around the teeth 
 is, therefore, as follows: The obvious lumps of tartar should be 
 removed without laceration, and then the bifluorid mixture 
 should be gently flowed around the neck of each tooth and into 
 
TREATMENT OF MOUTH INFECTION 
 
 83 
 
 each infected pocket. If there is intense inflammation of the 
 gums, the solution should at first be diluted with an equal 
 quantity of water. In acute inflammation the first two or three 
 weekly applications of the undiluted mixture cause intense pain. 
 After the diluted mixture has been applied at weekly intervals 
 two or three times, and great care observed in daily mouth hygiene, 
 the strong undiluted mixture can be used with comfort and ad- 
 
 Fig. 33. — Syringe for application of bifluorid of ammonium comp. The bulb 
 is soft rubber, the barrel celluloid, and the needle is a platinimi tube capable of 
 being bent in any direction. 
 
 vantage, great care being taken not to force it into the tissues, 
 especially into the young granulations that are forming at the 
 bottom of the pockets. This solution should be applied with a 
 platinum-pointed syringe with a celluloid barrel and a rubber 
 bulb (Fig. 33). The solution vigorously attacks glass, and 
 therefore such a syringe as described must be used. The gums 
 inside and out should be protected by napkins or cotton rolls, 
 
84 MODERN DENTISTRY 
 
 and the solution gently injected around the necks of the teeth 
 and within the pockets, the excess being wiped off with a napkin. 
 The patient should be allowed to spit without rinsing the mouth, 
 as the action of the saliva has a soothing and protecting effect 
 on the gums. If the solution is allowed to dry on the gums it 
 makes a burn not unlike that of pure carbolic acid. Where the 
 pocket extends along the tooth deep into the gums, it is sometimes 
 good practice to pack cotton between the root and the gum and 
 then soak it with the pure solution. This is not a painful pro- 
 cedure if properly done, and the next day the cotton can be re- 
 moved, thereby exposing the root to the bottom of the pocket, 
 when any remaining specks of tartar can be readily removed. 
 
 The methods just described will, in a majority of cases, be 
 sufficient to bring about a cure of mouth infection, but sometimes 
 recovery is slow or the general symptoms may indicate that the 
 mouth infection has infected other portions of the body beyond 
 the reach of ordinary local surgery or local therapeutic treat- 
 ment. In such cases it is obvious that a complete cure requires 
 the elimination not only of the mouth infection, but of all of this 
 same infection from every portion of the body. This is what 
 vaccine treatment is supposed to bring about. Therefore this 
 subject will be treated in the following chapter. 
 
CHAPTER V 
 
 VACCINES IN THE TREATMENT OF MOUTH INFECTION 
 
 Theory of Vaccination.— Bacterial vaccines are merely sus- 
 pensions of dead bacteria in physiological sahne solution. Vac- 
 cination is the injection of such suspensions for the purpose 
 of stimulating or increasing the antagonistic forces of the body 
 against the particular species of bacteria contained in the vaccine. 
 Just what these antagonistic forces are and the exact manner in 
 which they act have been subjects of the most careful investi- 
 gation ever since the epoch-making work of Pasteur, scarcely 
 three decades ago. As a result, certain substances or properties 
 of the blood-serum in vaccinated persons or animals have become 
 well-known facts. The antagonistic effects of these newly formed 
 substances upon the bacteria have been demonstrated in test- 
 tube experiments, and such reactions naturally suggest to a 
 certain degree the train of events following an injection of bac- 
 terial vaccines into the tissues. 
 
 Unfortunately, however, our knowledge is still incomplete; 
 the chemical and physical reactions that take place within the 
 living body are so subtle that pure hypothesis must supply the 
 connecting links between the known and the unknown. As 
 new facts are disclosed, many of our theories must be modified 
 accordingly, sometimes even discarded altogether. Our specu- 
 lations are merely a temporary scaffolding from which to erect 
 the soKd structure. 
 
 Thus, in the matter of therapeutic inoculation, experience 
 has taught us the essential points in the method of injection, 
 and the regulation of dosage; experience has also shown us the 
 great value of therapeutic inoculation. With regard, however, 
 to the intimate mechanism by which these results are obtained, 
 the current explanations offered must be regarded as working 
 hypotheses and nothing more. 
 
 85 
 
86 MODERN DENTISTRY 
 
 As just stated, vaccination consists in inserting dead disease 
 germs into the body so that the blood and tissue cells may be 
 stimulated to form a ferment that will destroy any invading 
 germs of the same species. When this has been done, two impor- 
 tant factors against the growth of these disease germs have been 
 created: first, the ferment that will destroy them is actually 
 present in the blood; second, the tissue cells have been impressed 
 with the habit of making this specific ferment in the presence of 
 these particular micro-organisms, so that in future if the tissue 
 ceUs find themselves adjacent to these germs, they will more 
 readily and effectively form the destroying ferment. 
 
 The injection of germs within the body so that the cells may 
 form the special germ-destro}dng ferment is called active im- 
 munization because it stimulates the body to be alert in its 
 defence against the presence of this germ. But where an animal 
 has been injected with disease germs until its blood is full of the 
 protective ferment, and this animal's blood is drawn off asep- 
 tically and the serum refined and injected into a patient purely 
 for the benefit to be derived from the protective ferments that 
 are in the serum, the procedure is called passive immunization 
 because this immunization does not create the habit of ferment 
 formation in the body cells of the person injected; it only pro- 
 vides a ferment that is known to be hostile to the germs with 
 which the patient is infected. Active immunization may last 
 for years, while passive immunization gives its protection for 
 only a few weeks at most. 
 
 The method by which the body is stimulated to destroy and 
 rid itself of invading infection has been investigated by EhrHch, 
 Metchnikoff, Wright, Besredka, and Vaughan with such inspired 
 research and such astute patience that the basal principles of 
 the theory of immunization seem fairly weU established; and 
 while there are differences in wording, the principles enumerated 
 by each investigator co-ordinate so thoroughly that the doctrine 
 will be treated as a whole, there not being sufi&cient space here to 
 discuss the special minute differences of their individual teachings. 
 
 Any protein that invades the body parenteraUy — that is, 
 otherwise than through the normal processes of the digestive 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION 87 
 
 tract — is called antigen, whether it is in the form of bacteria, 
 flower-pollen, horse-serum, or white of egg, etc. The ferment 
 which destroys this substance and causes its elimination is com- 
 posed of a combination of two substances called co?nplement and 
 amboceptor. Complement is always present in the blood in a prac- 
 tically fixed amount. The quantity cannot be markedly increased 
 by any known means. Specific amboceptor does not exist until 
 the body cells are stimulated to produce it. Its specificity is a 
 marked characteristic. It is active only against its correspond- 
 ing antigen. For instance, typhoid bacilli when they invade the 
 tissues of the body act as an antigen. They stimulate the creation 
 of a typhoid amboceptor that, uniting with the complement in 
 the blood, forms a ferment which breaks up the typhoid germ 
 into substances that are readily digestible by the blood and 
 tissues. Vaughan, in his magnificent work, "Proteins and Split 
 Products in Relation to Immunity and Disease," has shown 
 that the first destructive action of a ferment on the antigen is 
 to split it into a poison that is a common derivative of all proteins, 
 called the toxophore, and a harmless spUt product called the 
 haptophore, solely characteristic of the particular antigen from 
 which it is derived. For instance, the toxophores of streptococci, 
 goat-serum, or egg albumin are all toxicologically the same poison, 
 and when set free in the body give rise to the same symptoms, 
 but their respective haptophores, each non-toxic, are specific of 
 each protein from, which it is derived; and each haptophore 
 stimulates by its presence the formation of the particular 
 amboceptor as an increased defense against the invasion of its 
 corresponding antigen. 
 
 Therefore, it is clear that the administration of proteins 
 parenterally, whether serum or masses of bacteria, whether hving 
 or dead, may, under certain circumstances, be as potent in their 
 action for good or evil as strychnin or aconite. By a beautiful 
 series of experiments on animals Vaughan has shown that ex- 
 cept where the disease is caused by the few bacteria similar to 
 the diphtheria and tetanus germs, in that they secrete poisons 
 as they grow, fever and death from infectious diseases result 
 primarily from the breaking of protein bacterial masses into 
 
88 MODERN DENTISTRY 
 
 the toxophore and the haptophore groups. Therefore, if the 
 protein substance grows to a sufficient mass before the defensive 
 ferments of the body arrest its growth, so much poison may be 
 let loose upon the system that death results. If, however, the 
 defensive ferment or amboceptor is present or is formed in suffi- 
 cient quantity to stop the growth of the invading bacteria before 
 enough protein is formed to produce a lethal dose of the toxo- 
 phore, the poison is gradually and continuously destroyed and 
 the patient recovers. Vaughan has shown that the fever of 
 bacterial disease is not usually due to the growth of the germs, 
 but to their destruction, and the letting loose of the toxophore. 
 He has also shown that complete and effective digestion of a 
 protein will thoroughly destroy the toxophore, while during the 
 process the liberated haptophore will engender in the tissue 
 cells a habit of readiness in the formation of the amboceptor, 
 which thereafter will, whenever it meets it, destroy the particular 
 protein that called it into being. After the formation of the 
 amboceptor has ceased and the need for it has passed, there is 
 ordinarily a tendency for it to disappear, the future defense 
 being left to the educated tissue cells, although occasionally the 
 amboceptor is not eliminated, but remains in large quantities 
 in the blood. 
 
 Anaphylaxis. — The storing up of this amboceptor may work 
 for good or ill, according to circumstances. If a certain protein, 
 say horse-serum, is put into the body in small quantities and a 
 large quantity of amboceptor is formed and stored up, a second 
 dose of that protein may result in death by the sudden destruc- 
 tive action of the amboceptor, and the consequent pouring out 
 of the toxophore, that reaches a lethal dose before it can be elimi- 
 nated by the excretive and digestive processes of the body. 
 Some animals are much more prone to store up the amboceptor 
 in a dangerous marmer than others. The guinea-pig is most 
 prone to consistently do this. In man this propensity is, fortu- 
 nately, rare. For instance, if a guinea-pig is injected with i 
 c.c. of horse-serum, and at the end of ten to fifteen days 
 is injected intravenously with another cubic centimeter of 
 horse-serum, the guinea-pig will die of bronchial spasm. If, 
 
VACCINES IN THE TREATMENT OF MOU'lH INFECTION 89 
 
 however, the second dose consists of a different antigen, such as 
 white of egg or goat-serum, etc., the amboceptor present is not 
 effective, and death or even disturbing symptoms do not result. 
 Moreover, if the second dose of horse-serum is given in three 
 to five days, the amboceptor has not formed in sufificient quan- 
 tity to let loose a lethal dose of poison, and from then on the 
 doses can be given without the deadly symptoms that would 
 develop if the second dose had been deferred for fifteen days. 
 This state of being hypersensitive to a second dose is called 
 sensitization or anaphylaxis. In man anaphylaxis is a remote 
 though fatal possibility, and such a possibility is always present 
 when a serum is administered for the first time in large quantities. 
 How this sensitization occurs is not known, but that it does exist 
 in some individuals as a natural idiosyncrasy is an established 
 fact, and possibly fatal consequences can only be avoided when 
 serums are administered by careful adherence t o the precaution- 
 ary routine in each case. If a small trial dose of a particular 
 serum, say 0.05 c.c, is first given, and if at the end of an hour no 
 itching or gasping results, the full dose can then be safely admin- 
 istered because the trial dose will have shown that no ambo- 
 ceptor characteristic of that particular serum is present. If, 
 however, the small preliminary dose causes these symptoms, 
 showing that the ferment is present, the result will be harmless, 
 as there is not enough protein in 0.05 c.c. to develop a dangerous 
 quantity of toxophore. If the patient is thus shown to be sensi- 
 tized, and it is nevertheless essential that the serum be given, 
 two or three trial doses of serum can be given at hourly intervals, 
 so that the stored amboceptor will be gradually and safely ehm- 
 inated, and then the full therapeutic dose of serum can be admin- 
 istered without any anaphylactic symptoms developing. The 
 danger of bronchial spasms or fatal anaphylactic symptoms 
 is only to be feared in the use of serums, and with these only 
 when they are given in large first doses. 
 
 With vaccine the amount of protein represented by the dead 
 bacteria is so small that there is practically no danger of any 
 anaphylactic action other than a very occasional transient rash. 
 3,000,000,000 staphylococci or streptococci weigh only i milligram 
 
90 MODERN DENTISTRY 
 
 or less;^ 1,000,000,000 represents the maximum dose that is ordi- 
 narily given. Thus, if these micro-organisms were considered 
 pure protein, which they are not by a large percentage, a dose 
 such as the 3,000,000,000 bacteria represent would contain 
 much less protein than that found in 0.05 c.c. of horse-serum, 
 which is the prehminary test suggested by Vaughan to be given 
 to a patient to ascertain whether he can safely take antitoxin.^ 
 
 The principal caution to be observed in vaccine treatment 
 is to see to it that small doses are given at the start, and then 
 cautiously increased, in order that there may be complete diges- 
 tion, which will minimize if not entirely remove any depressing 
 action of the liberated toxophore. Thirty thousand killed bac- 
 teria grown from material taken from an apical abscess have 
 been known to cause such a severe reaction that a further re- 
 duction in dosage has been made and with final beneficial 
 results. After a dose of vaccine, if there is fever or depres- 
 sion lasting over a day, it is a sure sign that the interval be- 
 tween doses should be lengthened or the dose decreased, or 
 both. Sometimes a patient may stand a given dose for five 
 or six times at weekly intervals, and then suddenly show signs 
 of nausea or cerebral or ocular congestion. These are sjnnp- 
 toms that should never be disregarded. The vaccine should 
 be stopped for two weeks or more, until the symptoms have 
 entirely ceased, and then the minimum dose should be given 
 again, and slowly raised, great care being taken to stop short 
 at the first signs of the symptoms previously noted. It 
 should also be taken as a cardinal principle not to increase the 
 size of the dose while the patient is receiving a quantity that 
 apparently is sufficient to cause good progress. In this respect 
 patients vary in a remarkable degree. One patient will show a 
 marked reaction to 10,000 streptococci, while another can easily 
 accept 100,000,000. 
 
 The preparation of vaccines for use in vaccine therapy con- 
 sists of taking one or more species of the infecting germs, growing 
 these germs in suitable media, separating them according to 
 
 ^ Wilson and Dickson, "Journal of Hygiene," vol. xx, p. 49. 
 ^ "Protein Split Products," p. 471. 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION 9 1 
 
 species, combining them in a sterile salt solution according to 
 their recognized dosage per cubic centimeter, and destroying 
 their life but not their substance by heat or judiciously used 
 antiseptics. The vaccine having been thus prepared in the 
 laboratory is then injected into healthy tissue, which is 
 thereby stimulated to form the corresponding amboceptor. 
 This amboceptor, combining with the complement, then dis- 
 solves or causes the digestion of the infecting germs. When 
 the Kving germs of infection have overpowered a certain 
 mass of tissue cells, as in the case of a pyorrhea pocket, 
 these cells are unable to form the specific amboceptor neces- 
 sary to sensitize the germs of infection so that the blood can 
 dissolve them. If, however, these same germs are killed without 
 destroying their protein substance and are injected into healthy 
 tissue in judicious quantities, the healthy cells are stimulated 
 and trained in the habit of producing the specific amboceptor. 
 This amboceptor then joins with the complement and sensitizes 
 or dissolves the infecting germs wherever it happens to meet 
 them in the body. And this habit frequently lasts, so that the 
 cells always respond to the stimulation of the specific individual 
 infection, however small the stimulation may be. It is, however, 
 evident that if the infecting germs are in large masses or depots 
 surrounded by an inflammatory or protective wall, the ferment 
 wiU not be effective, no matter how high its percentage is raised 
 in the blood, since it cannot reach the germs growing within such 
 a defensive mass. Therefore the vaccine treatment will prove of 
 Httle value unless surgical means are used to remove or break up 
 the inflammatory waU. For that reason every means possible 
 should be used to mechanically remove these bacterial masses; 
 and when that is accomphshed the protective ferments in the 
 blood induced by the vaccine will amply be able to destroy the 
 remnants of infection and prevent such infection from travehng 
 through the blood-current to other parts of the body and forming 
 new spots or depots of infection. 
 
 Autogenous and Stock Vaccines. — ^There are tv/o kinds of 
 vaccine — autogenous and stock. The former is grown from germs 
 obtained directly from the seat of disease; the latter from germs 
 
92 MODERN DENTISTRY 
 
 that have the same microscopic and cultural characteristics, but 
 are obtained from various outside sources. The value of autog- 
 enous vaccine lies in the fact that the vaccine is derived from 
 onl}'^ those germs with which the body is already infected. Two 
 germs may show the same characteristics according to the micro- 
 scopic analysis and growth on culture-media, and yet be essen- 
 tially different in their pathologic reaction. It is clear, there- 
 fore, that the autogenous vaccine, scientifically made from the 
 invading infection, must induce the production of the appro- 
 priate amboceptor, while the stock vaccine may or may not do 
 so. The stock vaccine, however, has the advantage of being at 
 once available, while the preparation of the autogenous vaccine 
 takes from one to two weeks. Immediate availability is a great 
 advantage in acute, rapidly spreading infections where prompt 
 treatment is desirable ; but in chronic inflammations, such as those 
 around the gums, this haste is usually not needed. The stock 
 vaccine prepared from germs similar in appearance and growth 
 to the germs found in the infected area may produce the exact 
 amboceptor, may merely produce a similar one which is partly 
 effective, or it may produce an antibody that has no curative 
 action at all on the disease to be combated. The stock vaccine 
 has the great advantage that all the germs known to be gener- 
 ally associated with a disease can be incorporated in that vaccine, 
 while material taken for an autogenous vaccine may not contain 
 all of the important germs, some of which may He too deep to 
 be obtained, or may temporarily be missing in the spot of 
 infection from which the parent germs of the vaccine are 
 obtained. 
 
 While both vaccines have their advantages in the treatment of 
 mouth infection, it is perhaps the more conservative treatment 
 in ordinary cases to start with an autogenous vaccine whenever 
 efficient laboratory facilities are at hand; but where these facili- 
 ties are not available a stock vaccine, containing the principal 
 germs usually associated with the pockets of infection, will prove 
 valuable. 
 
 There are in the human mouth innumerable types of germs 
 that are present and grow according to the food eaten and the 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION 93 
 
 condition of the saliva. In fact, there is hardly any germ that 
 may not gain entrance to the mouth. Therefore, in obtaining 
 the parent germs for an autogenous vaccine, if great care is not 
 taken to obtain only those germs found deep within the pus 
 pocket, or within the actual walls of the inflamed region, an un- 
 limited number of extraneous germs may be taken, which would 
 give a vaccine not only of practically no value in restoring 
 the infected region, but would subject the system to unnecessary 
 strain. For instance, supposing some yeast or cheese germs 
 were obtained from the remnants of bread or cheese left around 
 the teeth, obviously a vaccine obtained from such accidental 
 flora could not be expected to cure pyorrhea. In the same way 
 there are doubtless many germs inhabiting the mouth that are, 
 as one might say, accidental, and the incorporation of these in 
 an autogenous vaccine may explain many of the failures of vaccine 
 treatment. As before stated, only the germs deep within the 
 infected pockets and within the infected tissues should be used, 
 and the method by which these parent germs can be obtained to 
 the exclusion of all others will now be discussed. 
 
 Obtaining the Parent Germs for a Vaccine. — When the in- 
 fected area appears at the tip of a root where the pulp has died 
 and the root canal has been filled, the root canal should be 
 drilled out with a fine sterilized piano-wire drill, until the end of 
 the root is nearly reached. The canal should then be sterilized 
 with a hot electric silver sterilizer. When this has been done and 
 the tooth has been carefully guarded with a napkin to prevent 
 infection from the mouth, another sterilized drill should be passed 
 down to the end of the canal and plunged through the tip into 
 the infected area. This drill should then be carefully removed 
 and streaked over blood-agar in such a way that the drill touches 
 nothing in its passage from the tooth to the tube containing the 
 blood-agar. The mouth of the tube should be passed through 
 a flame both before and after removing the cotton plug, and the 
 plug should be held between the second and third fingers of the 
 hand holding the drill. The tube itself should always be held 
 on its side, so that germs from the air cannot fall upon the nutri- 
 ent material. The tube should be carefully labeled with the name 
 
94 MODERN DENTISTRY 
 
 of the patient, the date the material is obtained, and the name of 
 the doctor obtaining it. A good way is to write directly on the 
 tube with a small rapidly revolving engine stone. This will 
 prevent the possibility of the label falling off and consequent 
 mistakes in the laboratory. The tube should then be sent to 
 the laboratory, and the growths planted as soon as possible. 
 
 When the area of infection appears near the tip of a root in 
 which the pulp is alive, the following method should be employed: 
 The mucous membrane over the indurated spot should be anes- 
 thetized and a thin cautery (see Fig. 25) plunged down to the 
 bone. An opening should then be made through the outer plate 
 of the alveolar process by a steriKzed bone-drill. At the end of 
 
 :^ 
 
 Fig. 34. — Instrument for obtaining material for autogenous vaccine. The 
 platinum spear is set in a ball-and-socket joint which is loosened or tightened by 
 the ratchet at the end of the handle. Dotted lines indicate various positions the 
 spear can assume. After material is obtained the instrument should be pointed 
 downward and the socket loosened until the spear drops into a straight line with 
 the instrument, then fastened into position by a turn of the screw-head, when the 
 instrument can readily enter the test-tube. (Author's instrument.) 
 
 two days the outer opening in the gum should be protected by 
 a napkin, anesthetized, and cauterized again. The point of a 
 small sterilized platinum-pointed glass syringe or platinum spear 
 should then be inserted into the bony opening, and, with the same 
 care previously mentioned, a drop of bloody fluid extracted and 
 transferred to the blood-agar tube. This material will un- 
 questionably contain the bacteria from the infected area that have 
 gathered and grown during the two intervening days, owing to 
 the lowered vitality of the wounded tissue. 
 
 In taking a specimen from a pyorrhea pocket the following 
 method should be used: The tooth should be protected from 
 mouth contamination by a sterilized cotton roll, the neck of the 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION 
 
 95 
 
 tooth should then be washed with sterile cotton dipped in sterile 
 salt solution so as to remove outside bacteria as much as possible, 
 and the mouth of the pocket and adjacent tooth neck should 
 then be slightly seared with the cautery. This can be done 
 without pain to the patient. Then a small cup-shaped spear 
 of thin platinum (Fig. 34) should be heated to a cherry red and 
 plunged to the bottom of the pocket. In this way a twofold 
 purpose is at once accompKshed — the extraneous germs near 
 the edge are destroyed by cauterization and the deep-seated 
 germs alone are collected on the thin platinum point, which has 
 
 
 Ja ^J 2^ 
 
 ^^ 
 
 Fig- 35- — Streptococcus. 
 
 cooled before reaching them. This renders it possible to carrj' 
 to the blood-agar only the germs presumably responsible for the 
 disease in question. It must not be forgotten that pus is some- 
 times sterile and the true cause of infection probably lies within 
 the walls of the abscess, and it is, therefore, from that region 
 alone that the material for the vaccine should be obtained. 
 
 In a study of over 300 cases the germs most frequently 
 and consistently found were: streptococcus, present in 95 per 
 cent, of the cases; Micrococcus catarrhalis and Bacillus in- 
 fluenzae in about 80 per cent., appearing together; pneumococcus, 
 
96 MODERN DENTISTRY 
 
 staphylococcus, and diphtheroids in a percentage sufficiently 
 consistent to indicate their probably great importance, and 
 finally a scattering of Friedlander's bacillus. Micrococcus tetra- 
 genus, and a few unidentified germs. 
 
 All the germs found except the spore formers are used in 
 the preparation of the vaccine. Staphylococci should show 
 300,000,000 to . the cubic centimeter; streptococci, diph- 
 theroids, pneumococci, Friedlander's bacillus. Micrococcus 
 tetragenus, and unclassified bacteria, 50,000,000 each to the 
 cubic centimeter. Where several strains of streptococci are 
 
 Fig. 36. — Bacillus influenzae. 
 
 found, they are usually combined so that all the strains mixed 
 together will not give over 100,000,000 to the cubic centimeter. 
 In ordinary cases of chronic pyorrhea the initial dose originally 
 given by the author was o.i of i c.c, and the dose was steadily 
 raised according to the reaction at the site of inoculation, and 
 the systemic response. If the patient showed exceptional frail- 
 ness, or the inflammation was unusually acute, or the blood- 
 count showed either a marked leukocytosis or lymphocytosis, 
 the initial dose was made much smaller. But it is the author's 
 practice now in every instance to start with much smaller doses. 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION 97 
 
 This is accomplished by having a second bottle of the vaccine 
 which contains a dilution of one- tenth or even one one-hun- 
 dredth of the original mixture, and in these cases it is astonishing 
 how often the minute dose will result in a satisfactory improve- 
 ment. These doses are generally given a week apart in the 
 arm or leg. When the hemoglobin is low or there is poiki- 
 locytosis the dosage should be watched with great care. 
 
 On account of the consistency with which certain germs were 
 found in gum infections it was considered that these were truly 
 pathogenic and, therefore, valuable in the preparation of a stock 
 
 Fig. 37. — Micrococcus catarrhalis. 
 
 vaccine. These germs are staphylococcus — aureus and albus — 
 streptococcus viridans, bacillus iniluenzse, pneumococcus, mi- 
 crococcus catarrhalis, and diphtheroids. These germs are so fre- 
 quently present that their presence cannot be considered without 
 significance; for it must not be forgotten that germs harmless 
 to normal and healthy tissue may assume virulent pathologic 
 characteristics when nourished in a mass of impoverished or 
 broken-down cells. The germs used in this stock vaccine were 
 obtained by mixing all the germs of similar types as they occurred 
 in about loo of my cases. For instance, all the different 
 7 
 
98 MODERN DENTISTRY 
 
 strains of staphylococci were mLxed together and the resultant 
 staphylococcus was the one used in the vaccine. The same pro- 
 cedure was followed with the other types mentioned. This 
 was done so that the various germs, when injected, would make 
 ferments that would have a broad specific action on the various 
 strains of bacteria to be combated. Such a vaccine is of special 
 value to those practitioners who do not have a laboratory at 
 
 
 Fig. 38. — Pneumococcus capsulatus. This germ when it infects the lungs and 
 causes pneumonia results in a frightful mortality owing to the mucilaginous capsule 
 that surrounds it. This capsule is particularly well shown on the three organisms 
 in lower portion of the plate. In one case material taken from a pus-pocket 
 around a tooth contained 80 per cent, of this micro-organism. After vaccine 
 treatment the gums healed promptly, and repeated examinations during a period 
 of three years failed to find this germ anywhere in the tissues around the teeth. 
 
 hand for the preparation of autogenous vaccines. The further 
 advantage of this stock vaccine lies in the fact that it can be 
 sensitized, if desired, with the sensitized serum of a goat, which 
 will make it possible to give it in much larger doses than would 
 be feasible with the ordinary autogenous vaccines. 
 
 Sensitized Vaccine. — If a sensitized vaccine is required, the 
 vaccine should be first made in the ordinary way, and given in 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION 99 
 
 large doses to a goat until the blood of the goat is surcharged 
 with the corresponding amboceptors. Then the goat is bled 
 and its serum containing the amboceptors is allowed to remain in 
 contact with the bacteria for twenty-four hours. The material 
 is then centrifuged and the bacteria are washed with a sterile 
 salt solution until all the free serum has been removed. The 
 germs are then counted and mixed in the proper proportions for 
 the vaccine. In the use of the sensitized stock vaccine the same 
 digestion takes place in the body as with the ordmary vaccines, 
 except that the digestion is more rapid and complete, since 
 the amboceptor obtained from the goat is already joined to the 
 germs. Thus the protein poison is supposed to be completely 
 destroyed, leaving the harmless protein products to increase 
 the percentage of the therapeutic amboceptor in the blood. 
 
 As before stated, in giving vaccines, it must not be "forgotten 
 that a dose that is borne with ease for a number of times in suc- 
 cession may suddenly cause a severe reaction. When this is the 
 case the same procedure should be followed as though the re- 
 action came from an increased dose. Why this occurs is not 
 known, but it is possible and probable that when the amboceptor 
 in the blood rises to an effective height it suddenly successfully 
 attacks masses of infection heretofore resistant, and thus the 
 body has thrown upon it not only the spHt products of germs 
 contained in the vaccine but also all the protein substance from 
 the germs destroyed in the body. An interesting symptom is 
 the occasional persistance of the lump or induration which forms 
 at the point of injection. It appears that this can be due only to 
 a lack of digestion and absorption of the bacterial bodies injected. 
 So long as the induration markedly persists we have an indication 
 that the potentialities of the vaccine injection have not been 
 exhausted. Therefore, under these conditions, further in- 
 jections may be temporarily withheld or smaller doses given, 
 while absorption in the seat of induration may be stimulated 
 by massage. 
 
 If there is a tendency to the rapid formation of creamy tartar 
 deposits on the teeth prior to the vaccine treatment, it wiU 
 be noted that as the antibodies are formed and the gums show 
 
lOO MODERN DENTISTRY 
 
 signs of healing, the tartar will be deposited much less rapidly, 
 and the tartar deposited is of a much more solid and removable 
 nature, and does not tend to burrow under the gum margins. 
 This change in the deposition of tartar I have come to consider 
 as a distinct symptom of the successful progress of the vaccine 
 inoculation. 
 
 AUen^ speaks of the value of citric acid in 30-grain doses, 
 three times a day, for the purpose of softening the lymph wall 
 around the foci of infection by reducing the coagulating power 
 of the blood. I have found the treatment of service, but give 
 it in the form of i ounce of lemon juice three times a day, which 
 is the equivalent of about 34 grains of citric acid for each dose. 
 
 When a pus pocket shows signs of sudden inflammation during 
 treatment, it is always wise to open it surgically, drilHng along 
 the root to be sure that there is no back pressure of pus and that 
 the antibodies have full opportunity to enter the seat of infection. 
 For, above all things, it should be remembered that vaccine 
 treatment can be successful only when accompanied by judicious 
 local treatment of a surgical and therapeutic character. 
 
 When there is active tuberculosis, vaccine, in my experience, 
 should be avoided, or, if given, it should be given with extreme 
 caution. When there is a history of active tuberculosis that has 
 healed, any cough or acute inflammation in the joints develop- 
 ing during the vaccine treatment should be looked upon as a 
 danger signal. When the glands suddenly become enlarged and 
 the clinical thermometer shows a rise in the evening to 100° 
 F., or a rash appears suddenly over the nose and upper cheek 
 bones, the vaccine should be stopped altogether for a considerable 
 period, and if it is recommenced, a dose of not over 10,000 
 or 20,000 germs should be given at the start, and the daily 
 temperature carefully noted as a guide. These compHcations 
 are rare, fortunately, but nevertheless should always be recog- 
 nized at their first appearance. 
 
 Vaccine dosage is a problem that is being solved by accredited 
 clinicians in a manner that theoretically might seem altogether 
 to discredit vaccine therapy as a science. Initial doses of 
 
 ^ "Vaccine Therapy and Opsonic Treatment," p. 126 (Blakiston). 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION lOI 
 
 500,000,000 to 1,000,000,000 are given on the one hand, while 
 other practitioners find that doses of one one-thousandth or even 
 one-ten-thousandth of these quantities give satisfactory thera- 
 peutic results. 
 
 One cannot help feeHng that the state of knowledge concern- 
 ing the routine administration of vaccines is about the same as 
 that held formerly in the routine administration of calomel or 
 quinin, when these were first discovered and administered as 
 drugs — 10- to 15-grain doses of calomel were given, fre- 
 quently with good therapeutic results, and then again saliva- 
 tion sometimes occurred under such dosage with permanent 
 injury. In the same way quinin was frequently administered 
 in 50- or 60-grain doses. When the patient was not sensitive 
 to quinin unquaHfied good results were obtained, but when 
 there was an idiosyncrasy, disastrous if not fatal effects were 
 encountered. 
 
 Some seven years ago when the author began to give vaccines 
 he also used large doses. He gave himself experimentally forty- 
 two weekly doses of vaccine, thirty-two of which each con- 
 tained 1,100,000,000 mixed germs. The results were excellent. 
 But during the first four or five years of his experience with this 
 treatment, he encountered very occasionally, reactions so serious 
 that at times he wondered whether the anxiety and worry made 
 the treatment worth while. However, satisfactory cures were 
 obtained in 90 per cent, of the cases without any bad symp- 
 toms, so that there was more than suflS.cient encouragement to 
 persevere. Nevertheless, the result of experience steadily im- 
 pelled the use of smaller doses, so that instead of starting 
 with a minimum dose of 12 to 25 or even 50 milHon germs, 
 if the vaccine consisted of four or five different species; 
 the chnician may now start with a dose of 30,000, and in 
 some very exceptional cases this dose has to be reduced in- 
 stead of increased. In a certain percentage of cases it will 
 prove harmful to give an initial dose of 5 to 10 million 
 germs until the tolerance of the patient is carefully ascer- 
 tained. An intense reaction, as shown by depression, fever, 
 acute or local inflammation, or marked variations in the blood- 
 
I02 MODERN DENTISTRY 
 
 pressure, is undesirable. By just avoiding these symptoms, 
 better therapeutic results will be obtained. 
 
 Incredulity will be aroused by this statement, but a little 
 consideration will show that it is not so preposterous as it may 
 at first appear. Webb has found that one or two living tubercle 
 bacilK when injected hypodermically are capable of giving ex- 
 cellent clinical results, and Myer Solis-Cohen (Archives of 
 Pediatrics, January, 1918) has shown that one ten-millionth 
 of a milligram of tuberculin residue may be an effective dose. 
 If this is so, why then should the tubercle bacillus be absolutely 
 in a class apart from all of the other organisms that infect the 
 body? During the last two years the author has been growing 
 cultures anaerobically from material taken from the tips of 
 extracted teeth. Formerly aerobic cultures alone were used, 
 but by anaerobic cultivation he and his laboratory assistant 
 appear to have discovered a new Gram-negative cocco-bacillus 
 that is associated with the absorption of root tips, which germ 
 seems to have extreme virulence and toxicity. This new germ 
 may partly but not entirely account for the reactions that oc- 
 casion the reduction in dosage. 
 
 It is claimed by many observers that certain people cannot 
 advantageously take vaccine. This statement, when applied 
 to autogenous vaccines, seems illogical, for, as a matter of fact, 
 the patient by the mere presence of the disease has already taken 
 the germs in a living state. Any patient suffering from a local- 
 ized infection can safely and usually beneficially take an au- 
 togenous vaccine prepared from the localized infection if judi- 
 cious dosage is employed. And so again, we come back to the 
 question of dosage. The determination of the size of the dose 
 depends primarily on the interpretation of what constitutes 
 a true reaction, and this interpretation is dependent upon a 
 nice discrimination. 
 
 Seven or eight years ago the general procedure was to start 
 treating a so-called normal patient with 12,000,000 to 25,000,000 
 germs. If the patient showed depression or fever that did not 
 last twelve hours the dose was doubled, and after a while it was 
 again doubled, and doubled again, until incredibly large doses were 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION I03 
 
 given, the patient each time getting a terrific therapeutic bump. 
 If the patient did not get a bump the dose was increased, and 
 if he did get a bump the dose was also increased, because it was 
 noted by many authors and clinicians that those patients who 
 had the worst reactions made the best recoveries. And so the 
 rather loose philosophy of vaccine dosage seemed to be, "Give 
 the patient small doses at first and increase them so as not to 
 have too great a reaction, but if the patient does have too great 
 reaction he will have a better recovery." Either way it's all 
 right, and — strange to say — this vague unphilosophic theory of 
 dosage seems ordinarily to have worked out very well. 
 
 The large doses administered gave good results and still 
 do give good results in a great majority of cases, but in a small 
 though important percentage of cases they still do harm, and as 
 the unfortunate results always make a greater impression than 
 the good results it was not surprising that many physicians gave 
 up the use of vaccines altogether. Many thousands of ])hy- 
 sicians were getting such good results, however, that the des- 
 pairing cries from some esteemed leaders were not sufficiently 
 conclusive to make them discard vaccines. Many of us felt 
 too sure of the value of the treatment to be stampeded by 
 crudities that must of necessity be remedied in the near 
 future. 
 
 In the author's opinion there must be more careful inves- 
 tigation into the effect of small doses of vaccine. Doses of 
 150,000,000 to 300,000,000 germs are still given by the au- 
 thor, but invariably a small dose is given first. The aver- 
 age patient with his various latent infections, is very much 
 in the position of a many chambered magazine containing 
 powder, that must be touched off without blowing out the 
 sides of the building. If each room of the magazine has small 
 quantities of powder in it and the powder is sHghtly damp 
 or slow-burning, the task is comparatively simple and one room 
 at a time can be safely fired by a judicious explosive charge. 
 On the other hand, if there are an infinite number of compart- 
 ments each full of explosive, and instead of slow-burning powder 
 we have dynamite, the difficulty is greatly increased and much 
 
I04 MODERN DENTISTRY 
 
 greater caution in the size of the explosive charge must be 
 used. 
 
 Let us now recite briefly a few cases that have reacted in 
 an astonishing way to small vaccine doses. There are many 
 other cases that could be quoted that unmistakably responded 
 clinically to small doses, but a mere piling up of cases would be 
 tedious and unconvincing. 
 
 The first case was a man aged forty, who had gouty deposits 
 in the ears, crepitus and pains in the knee-joints, associated with 
 sharp pains along the tendons of the thighs and legs whenever 
 he walked — a typical case of systemic infection from diseased 
 teeth and gums. The infected teeth were extracted and an 
 autogenous vaccine was made. The first dose of 150,000 germs 
 made him uncomfortable, the second dose, a week later, of 
 210,000 germs sent him to bed with inflammatory fever, painful 
 joints, and swollen ears. After two weeks when the symptoms 
 subsided a dose of 30,000 germs was given that made his ears 
 swell a little, but the dose was well borne. At four weekly 
 intervals he was given 30,000 germs, with marked improvement. 
 Then he was given 60,000 germs and promptly went to bed 
 again, this time for only two days. Then 30,000 germs were 
 given at weekly intervals for six times, and he made a most 
 satisfactory recovery. 
 
 There are other cases where the patient showed marked 
 improvement and also marked systemic reaction to weekly 
 doses of 6000 to 15,000 germs, but one is of especial interest — 
 that of a married woman, aged thirty-six, of the systemic in- 
 flammatory t3^e, teeth sensitive to heat and cold, resisting all 
 treatment. When she came for treatment she had just weaned 
 her baby. The first dose of 30,000 germs caused her breasts 
 to become painful and to swell. There was also a vaginal dis- 
 charge and she was depressed and ached all over. A week later 
 she was given 15,000 germs, with similar reactions but less 
 marked, and these symptoms recurred seven times at weekly 
 intervals, although the dose was reduced to 9000 germs. The 
 breast and vaginal reactions are particularly interesting, as they 
 could not have been the result of neurasthenia or hysteria. 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION 105 
 
 Meantime she showed marked improvement and the teeth were 
 successfully treated and filled in a manner theretofore quite 
 impossible. 
 
 Another case is that of a woman aged sixty-two, who could 
 not bear 30,000 germs without a severe reaction, but could stand 
 15,000 germs. Finally, 60,000 germs were tried as a test, and 
 she had great depression and lymphatic enlargement, especially 
 in the groins. For two days she was so weak that she required 
 cardiac stimulants. 
 
 In closing the discussion of dosage it might be well to state 
 the present method of the author for ascertaining the proper 
 vaccine dose. Thirty thousand germs are usually given at 
 the start and raised by weekly doses so long as the patient 
 bears the dose well, even if the dose goes up to 1,000,000,000. 
 However, when the patient is showing satisfactory improvement 
 under a dose, that dose is maintained. If 30,000 germs are not 
 accepted easily, the dose should be reduced to a number that 
 is easily accepted. It is also especially important that the 
 patient should be carefully watched for reactions. 
 
 When grip and colds are prevalent the patient who is given 
 a dose that cannot readily be borne is apt to get sore throat or 
 grip. Such an attack must be regarded not as an unimportant, 
 accidental symptom. It should always be regarded as a possible 
 reaction calling for dose reduction, and if the cold or grip should 
 recur regularly with the vaccine administration, its recurrence 
 should be considered conclusive evidence that the sore throat, 
 cold, or grip is a real reaction, calling for a corresponding modi- 
 fication in dosage. 
 
 It has been the author's experience that reactions occur in 
 widely different forms and require most careful analysis on the 
 part of the physician if the best results for the patient are to be 
 obtained. It has also been his experience that large doses given 
 at the start seem to mask a fine gradation of symptoms by 
 which a just analysis of the patient's needs may be ascertained. 
 Large doses may be accepted by the body when roused to com- 
 bat a pathologic assault, and being aroused, it protects itself, 
 but at the same time finds its energies exhausted, while the 
 
Io6 MODERN DENTISTRY 
 
 exactly ascertained dose that will just stop short of a reaction, 
 will philosophically give the best therapeutic effect. 
 
 The author's vaccines are standardized by Wright's method 
 Controlled by turbidity tests. 
 
 Vaccines and Anemia. — A patient came to me with a hemo- 
 globin of 30 per cent., red cells 3,616,000, white cells 4500, 
 with microcytes, macrocytes, and poikilocytes. The patient 
 was so weak that she could hardly walk. I extracted three 
 roots and put her mouth under proper cleansing, and in five 
 days her hemoglobin rose to 37 per cent., the macrocytes, 
 microcytes, and poikilocytes disappeared, and the red cells 
 began to accept the stain in a more normal manner. She 
 was advised to take 3 raw eggs three times a day before meals, 
 and the vaccine, composed of i diphtheroid, i pigmented 
 streptococcus, and i non-hemolytic streptococcus, was given 
 once a week. For a while improvement hung fire. After each 
 dose of vaccine the hemoglobin would drop during two days 
 through a range of 3 or 4 points, and then it would slowly 
 climb up a Kttle higher than at the start, so that gradually the 
 hemoglobin reached 50 or more; the red cells rose to over 4,000,000 
 and the leukocytes to 9000 or 10,000. The patient's eyes lost 
 their yellow cast and, from being hardly able to walk, she steadily 
 increased in strength so that she felt better than she had in years. 
 In this case, without the blood-count as a guide, the vaccine 
 might have resulted in disaster. 
 
 Vaccines and Osteo-arthritis. — Two cases of pronounced 
 osteo-arthritis evidently caused by mouth infection will now 
 be given. The first was that of a man who had been suffering 
 for three years with rapidly progressing arthritis deformans, 
 associated with hardening of the arteries. He was just able 
 to walk with the aid of two canes. He came to me as a last 
 resort for a possible slight relief. I found three necrotic teeth 
 which I extracted. There were numerous Hve infected pulps 
 that were removed and the canals antiseptically filled. The 
 pockets of infection were invariably associated with loose, pain- 
 ful teeth. The pockets of infection were treated surgically, 
 a scientific mouth hygiene was instituted (see Chapter II), the 
 
VACCINES IN THE TREATMENT OF MOUTH INFECTION 107 
 
 pockets were syringed with bifluorid of ammonium, and the 
 
 patient cautiously given autogenous vaccine once a week. At the 
 
 end of the fourth week he took off his iron boot and was able to 
 
 walk with but one cane. He soon was able to bend his knees 
 
 and cross his legs, which before had been impossible. Before 
 
 long he walked from the station to my office, a distance of half 
 
 a mile, and finally, in about six weeks, was able to walk a short 
 
 distance without the cane. In the meantime the pockets of 
 
 infection disappeared, and the teeth tightened to the point 
 
 where mastication was comfortable and effective. During the 
 
 administration of the vaccine he had no reaction whatever, 
 
 until finally after the twelfth administration the erythrocytes, 
 
 hemoglobin, and leukocytes suddenly began to drop. The 
 
 vaccine was at once stopped and he was dismissed, being put on 
 
 a low protein diet and being warned to keep up the prescribed 
 
 mouth hygiene. He continued to improve, but in the course of 
 
 a year carelessness in mouth hygiene caused a reinfection, and 
 
 at the same time brain symptoms due to hardening of the arteries 
 
 set in, so that he was finally confined to his chair through mental 
 
 inertia. The treatment was renewed, and in the course of a 
 
 year he made a satisfactory recovery as far as his joints and 
 
 inflammatory symptoms were concerned. 
 
 The other case was one to which I was called in consultation. 
 This patient, a man aged sixty-seven, was unable to move him- 
 self about without excessive pain in practically all of his muscles 
 and joints. There were three necrotic teeth and pockets of 
 infection about the other teeth. The necrotic teeth were ex- 
 tracted, and an autogenous vaccine made from the infected 
 pockets. He was treated as has been described in this chapter. 
 He came from the hospital to my office just four times, a week 
 apart. The first two times he came in the ambulance, the 
 third and fourth times in the trolley cars, and walked with Httle 
 difficulty, and then he insisted that he was cured and that he 
 was going to his home in West Virginia. 1 told him that he was 
 foolish, that he was not cured, but still he insisted and went, 
 and, much to my surprise, he appears to have been right, for 
 he kept on improving and now gets in and out of the bath-tub 
 
Io8 MODERN DENTISTRY 
 
 and is in every way normal, so his son, who is a doctor, tells me. 
 He took the vaccine with him and received weekly doses for a 
 period of four months. His leukocytes when he entered the 
 hospital were 15,600, and in two months they had dropped to 
 9400, where they remained. 
 
 The discovery by Barrett and Smith of the ameba in the 
 pyorrhea pocket was considered most important as presenting 
 the possible cause of mouth infection, and consequently ipecac 
 and its alkaloid, emetin, have been given in numerous instances as 
 a possible specific in this disease. I have used emetin, f grain, 
 administered h3Apodermically in the arm or back for ten suc- 
 cessive days during the treatment of mouth infection, but have 
 no reason to beHeve that it is of great value. I have also used 
 it in local appHcations, but have felt that in this respect it is less 
 valuable than the bifluorid ammonium comp. This would 
 indicate that the ameba is not the specific cause of mouth 
 infection. In my opinion, no single drug or vaccine can ehminate 
 mouth infection when it is once intrenched. It can only be cured 
 by the judicious dentist, who must determine just what surgical 
 and therapeutic procedures will be effective. Any specific cura- 
 tive claim for surgery, vaccine, or drugs alone will certainly 
 retard, not advance, the cure of mouth infection. 
 
 In closing this chapter I would emphasize the necessity for a 
 complete preKminary study of the patient by a competent 
 physician who will diagnose, as well as may be, the condition of 
 all the organs of the body, so that when the vaccine is given, 
 this diagnosis may be borne in mind and the dosage modified 
 accordingly. 
 
CHAPTER VI 
 
 TREATMENT OF ROOT CANALS 
 
 EXCISION OF INFECTED OR NECROTIC ROOTS 
 
 Alveolar Abscess. — One of the most important causes of 
 mouth infection is the alveolar abscess, due to deterioration 
 of the dental pulp which forms the tooth bone or dentin. The 
 term "dental pulp" will be used to designate the mass of sensitive 
 tissue within the tooth, that among the laity is generally desig- 
 nated as the tooth "nerve." 
 
 After a tooth has been erupted for a period of from eight to 
 ten years the essential constructive work of the pulp may be 
 said to have been finished. From then on it slowly shrinks 
 within the bony walls which it still continues to gradually form, 
 and on the sKghtest provocation accepts infection and calcic 
 infiltration, so that from being a benefit it is a distinct burden 
 and menace to the usefulness and health of the tooth. The 
 chief source of nourishment of a developed tooth is found in the 
 peridental membrane that envelops the root or roots, and this 
 membrane is amply able to maintain the tooth in comfort and 
 stability if there is no comphcation occasioned by infection and 
 nerve irritation. If the pulp is a healthy, nourishing one, it is 
 of unquestioned benefit to the tooth, but when it becomes in- 
 fected and irritated so as to be a depressing burden, the sooner 
 it is removed the better, leaving the healthy peridental membrane 
 to fulfil the functions of maintenance and nutrition. But if 
 through the infection of the pulp the peridental membrane also 
 becomes irritated and infected, the tooth will become loose and 
 in danger of being lost. 
 
 A comparatively smaU cavity in a tooth will allow infecting 
 organisms to reach the pulp that may or may not repel the in- 
 vasion, but when the soft decay itself reaches the pulp, so that 
 
 109 
 
no MODERN DENTISTRY 
 
 its removal causes an obvious exposure, the pulp must be re- 
 moved and the root canals filled. Any other procedure is in- 
 excusable. Many an alveolar abscess is derived from an infected 
 pulp and will resist all treatment until the pulp is removed, and 
 then the abscess will heal of itself. Many a loose tooth will 
 refuse to yield to the treatment designed to tighten it until the 
 living pulp is removed, and then it will rapidly become firm. 
 Many times a double-rooted tooth apparently sound and un- 
 decayed has developed soreness, looseness, and supersensibility 
 to heat and cold. A careful exploration will show that one of 
 the roots has become infected at the tip by a peridental abscess, 
 which has destroyed the blood circulation in the canal of the 
 root, thereby rendering the pulp half-dead and half-alive — a 
 menace not only to the welfare of the tooth and jaw, but to the 
 health of the entire body. Therefore, when the pulp of a tooth 
 is exposed through decay, or when there is excessive response 
 to heat or cold, or when peridental inflammation is combined 
 with looseness and there is no response to thermal change, 
 the pulp should be removed and the canals sterilized and properly 
 filled. Where, however, all the teeth become sensitive at once 
 or are insensitive to thermal change, we must look for a systemic 
 cause or an idiosyncrasy. Spinal irritation associated with 
 osteoarthritis, lead- or mercury-poisoning, or even an onset of 
 grip may cause a general type of irritation which will frequently 
 depart with the subsidence of the systemic lesion. It must 
 be remembered that some teeth are naturally insensitive, an 
 idiosyncrasy occasionally found, and it would obviously be ill- 
 advised to destroy the pulps in teeth that had the general charac- 
 teristic of insensibility as their sole pathologic symptom. How- 
 ever, there will ordinarily be no difiiculty in differentiating be- 
 tween the local and general disturbance, since with the local cause 
 there will be great variations in the individual teeth, while with 
 the idios5^crasy or general cause all the teeth will be affected 
 in practically the same manner. 
 
 Local Anesthesia. — In inducing local anesthesia the author 
 has found the Farbwerke-Hoechst tablets of novocain-suprarenin 
 to give the best results, the tablet marked E, containing 0.02 gm. 
 
TREATMENT OF ROOT CANALS 
 
 III 
 
 or ^ grain of novocain with 0.00005 gram of suprarenin, being 
 the one usually used. The best results are obtained by dis- 
 solving the tablet in 2 or even 4 c.c. of Ringer's solution, which 
 makes a i or 0.5 per cent, solution. A sterile normal salt solu- 
 tion containing 0.7 per cent, chlorid of sodium has been used for 
 this purpose in order that the percentage of salt injected should 
 be the same as the salt in the blood-serum, and this has given 
 good results, but the Ringer solution is less irritating to the tis- 
 
 Fig. 39. — A, glass flask in which Ringer's solution can be sterilized; 5, suitable 
 casserole in which solution of novocain and suprarenin can be dissolved and finally 
 sterilized by boiling. 
 
 sues and is productive of more rapid infiltration and anesthesia. 
 This is no doubt largely due to the calcium chlorid which is 
 present. The Ringer solution is made by dissolving i Ringer 
 tablet in 10 c.c. of distilled water. It contains sodium chlorid 
 0.5 per cent., calcium chlorid 0.04 per cent., and potassium chlorid 
 0.02 per cent. Distilled water must be used for the solution, as 
 the suprarenin is seriously affected by any alkaline traces. The 
 flask recommended by Reithmiiller, as shown in Fig. 39, A, 
 
112 MODERN DENTISTRY 
 
 for holding the solution, is excellent and practical. The solution 
 should be made up as described and sterilized for ten minutes, 
 preferably in a small electric sterilizer. When it is cooled it 
 should be put aside for use as needed. When the novocain- 
 suprarenin solution is to be made, 2 or 4 c.c. of the solution should 
 be poured out of the flask into the porcelain casserole recom- 
 mended by Fischer, shown in Fig. 39, B, and raised to the boiling- 
 point. While hot, one of the E tablets should be added to make 
 either a i or | per cent, solution, and the mixture again raised to 
 the boiling-point. It should then be drawn into a sterile syringe 
 and injected at blood temperature into the tissues, the spot of 
 injection being first touched with alcohol or tincture of iodin. 
 The solution should remain clear. If it turns reddish or is floc- 
 culent it should be thrown away as unfit for use. Such changes 
 usually occur because distilled water was not used for making 
 up the mixture. The anesthetizing solution should be freshly 
 prepared for each operation, as it quickly deteriorates. The 
 great advantage in using the tablets hes in the fact that they will 
 not deteriorate so long as they are kept dry and sealed, and also 
 in the fact that as they contain a fixed amount of novocain and 
 suprarenin there can be no chance of a mistake occurring in the 
 amount of drug administered. The amount of drug is exactly 
 known, and it is wise to over- rather than underdilute it. For 
 instance, a | per cent, solution of novocain is better for gum or 
 periosteum infiltration than a i per cent, solution, although 
 some feel that a i or even 2 per cent, solution gives quicker and 
 better results when used for infiltration around a nerve trunk. 
 The author uses the 0.5 per cent, solution wherever possible, 
 and always in frail or nephritic patients, or those having a 
 tendency to arteriosclerosis. In such cases if an extra quantity 
 of the anesthetizing solution is required, pure novocain can be 
 added with the corresponding amount of Ringer's solution. 
 It is particularly advisable not to increase the suprarenin above 
 0.00005 gi^-7 the amount contained in one of the E tablets, for 
 even if the entire amount of the solution is given it is only about 
 one-sixth of the generally accepted maximum dose. Novocain 
 has been given in doses up to i gram or 2 grams, and there- 
 
TREATMENT OF ROOT CANALS 
 
 "3 
 
 fore need not be a source of especial care, since a twentieth or 
 even a thirtieth of this amount is seldom needed in any one opera- 
 tion. This non-toxicity of novocain is a great blessing, and co- 
 cain should no longer be used for local anesthesia, for in using 
 cocain one is handHng a drug of such deadly possibihties that one 
 never knows when one will have to fight desperately for the 
 life of the patient. Ordinarily o.i or even 0.5 grain of cocain 
 will be received hypodermically with perfect complacency, 
 but occasionally a patient will show alarming symptoms of col- 
 lapse under ridiculously minute doses. The author remembers 
 an extreme case where a patient grew white, cold, and uncon- 
 
 Fig. 40. — Local anesthetic syringe. It will hold e c.c. Its fittings are all metal 
 or glass, making complete sterilization simple and easy. 
 
 scious from the administration of 0.013 grain of cocain, and 
 only the promptest measures saved his life. Cocain is a veri- 
 table tiger in the jungle, always ready to spring upon the backs 
 of those compelled to use it. Novocain shows no such tendency, 
 and with ordinary caution is a perfectly safe drug. 
 
 Any good sterile hypodermic syringe of the type shown in 
 Fig. 40 may be employed. Platinum needles are preferable 
 to steel, as the latter rust and break easily. The short needle, 
 23 mm. in length, can be used for ordinary gum infiltration, 
 while the long needle, 42 mm. in length, is all that is needed 
 for nerve-blocking, a process which will be described later. 
 
114 MODERN DENTISTRY 
 
 Gum Infiltration.— Ordinarily the pulp of any single-rooted 
 tooth can be painlessly removed at the end of five or ten minutes 
 after the injection of 0.02 gm. of novocain and 0.00005 S^- of 
 suprarenin under the periosteum about the tip of the root. The 
 point of the needle should be inserted beneath the periosteum 
 at the labial aspect adjacent to the apical foramen of the root 
 to be treated, and 2 c.c. of the solution slowly injected. The 
 needle should then be withdrawn, and the same procedure 
 should be carried out on the lingual side of the tooth. This, 
 in a modified form, applies to all of the upper teeth. In inject- 
 ing the Hngual sides of the upper bicuspids the needle should be 
 inserted in the peridental membrane at the neck of the tooth, 
 since the tissues of the palate in this region are very sensitive 
 to the stab of the needle. This same procedure also applies to 
 the lower teeth as far back as the first molar, but as nerve-block- 
 ing is so wonderfully effective in the lower jaw it should always 
 be given a trial before the infiltration method is used. Sometimes 
 it is necessary to supplement one with the other. 
 
 Nerve-blocking consists of flooding a nerve trunk with an 
 anesthetic so as to temporarily stop the passage of sensory 
 impulses. The inferior dental nerve as it enters the inferior 
 dental canal on the inside of the ramus of the jaw can be flooded 
 with a solution containing 0.02 gm. of novovain and 0.00005 g^- 
 of suprarenin, and the lower jaw and lip on that side rendered 
 numb and insensitive for an hour or two. At the expiration of 
 that time the sensibiHty of the jaw will be restored to its normal 
 condition. If the nerve is flooded as it comes out of the mental 
 foramen that region of the lower jaw between the second bicuspid 
 and the median fine will be deadened in a similar manner. 
 
 Nerve-blocking. — The method of nerve-blocking as applied 
 to the inferior dental nerve before it enters the inferior dental 
 canal is as follows: The syringe should be filled with 2 c.c. of 
 Ringer's solution in which an E tablet has been dissolved. The 
 solution should be blood temperature or a little warmer. The 
 syringe should be fitted with the 42-mm. platinum needle. The 
 gum should be painted with iodin where the injection is to be 
 made, and then the finger of the left hand should feel for the 
 
TREATMENT OF ROOT CANALS 
 
 115 
 
 lingual edge of the inferior maxillary ramus (Figs. 41, 42), just 
 back of the third molar. This edge, owing to the sudden widen- 
 ing of the jaw, lies in a line with the external cusps of the molars 
 and is designated by A. The ridge B, marking the outer surface 
 of the ramus, can be felt about f inch exteriorly. When the 
 inner edge has been carefully palpated, the point of the hypo- 
 dermic needle should be inserted just along the bone in the 
 direction of the line A-C, outside of the periosteum, about | 
 inch above the occlusal line 
 of the lower molars. When 
 entrance has been made and 
 the surface of the ramus felt, 
 the point of the needle should 
 be passed along the surface 
 of the bone for about | inch, 
 curving as shown by the 
 dotted line, and keeping the 
 direction of the puncture in 
 the occlusal plane of the lower 
 teeth. At this point, D, 0.2 
 c.c. should be slowly injected 
 to deaden the Hngual nerve. 
 At this place the direction of 
 the syringe should be changed, 
 as in the arc C-E, so that 
 finally the handle of the 
 syringe will rest across the 
 junction of the first bicuspid 
 
 and canine on the other side of the jaw. This is necessary 
 in order that the needle point may follow the curve of the 
 ramus. The needle is then advanced in the Hne of E~F to 
 a depth of 0.6 to 0.8 inch along the bone and the remaining 
 contents of the syringe slowly discharged at F. The mandibular 
 sulcus containing the inferior dental nerve is shown by G. The 
 point of the needle should always lie away from the bone rather 
 than toward it, and if there is any tendency for the needle to 
 jamb or stick it should be withdrawn slightly and advanced in 
 
 Fig. 41. — Diagrammatic illustration 
 of directions and movements of li3rpo- 
 dermic syringe during application of an- 
 esthetizing solution to the trunk of in- 
 ferior dental nerve. 
 
ii6 
 
 MODERN DENTISTRY 
 
 such a manner that an unobstructed entrance can be obtained. 
 At the end of three minutes there should be a tinghng and numb- 
 ness of the Up, at the end of ten minutes the entire side of the 
 face should have become anesthetized. The surgical work can 
 then be commenced. 
 
 An injection just posterior to the tip of the first lower bicuspid 
 will anesthetize the inferior dental nerve as it emerges, while an 
 injection just back of the superior canine tip will have a similar 
 effect on all of the teeth anterior to the point of the injection. 
 
 Fig. 42. — Lower jaw, showing the syringe and point of needle in final position 
 when the local anesthetic is discharged for the purpose of infiltrating the inferior 
 dental nerve as it enters the inferior dental canal. 
 
 In such cases the short needle is sufficient. An injection high up 
 on the maxillary tuberosity between the second molar and the 
 wisdom tooth will also anesthetize the three upper molars. For 
 this the 42-mm. platinum needle is used. Those desiring fuller 
 particulars on local anesthesia are referred to Fischer and Reith- 
 mliller's book, "Local Anesthesia in Dentistry." 
 
 Valuable as infiltration and nerve-blocking are, they do not 
 always prove successful in completely taking away the sensibility 
 of a badly inflamed pulp that is to be removed; but where a 
 
TREATMENT OF ROOT CANALS 
 
 117 
 
 tooth is to be extracted, or an alveolus is to be driUed, or a root 
 end is to be amputated, the methods just mentioned are to be 
 relied upon. If, therefore, the pulp is very much inflamed, the 
 infiltration method will have to be supplemented by pressure 
 anesthesia, a combination that gives very satisfactory results. 
 Where the tooth is insensitive or quiescent, and the pulp is 
 almost or entirely exposed, the local anesthetization by pres- 
 sure alone with novocain-suprarenin seems to give the best 
 results. In spite of every precaution there is occasionally pain 
 and soreness for an hour or two after the infiltration or nerve- 
 
 Fig. 43. — Central incisor, showing pyorrhea pocket. 
 
 blocking, while under ordinary conditions the pain occasioned 
 by pressure anesthesia is at the time insignificant and usually 
 involves no after-soreness. 
 
 Pressure Anesthesia. — The method of forcing novocam- 
 suprarenin into the pulp of a tooth will now be described. In 
 order that the complete technic may be given the case presented 
 will be that of a tooth where the enamel has neither been injured 
 by a blow nor decalcified by decay. In such cases the entrance 
 to the pulp is correspondingly simplified. 
 
 Figure 43 represents a single-rooted tooth. A represents the 
 enamel covering the tooth that normally extends to the gum: 
 
IIJ 
 
 MODERN DENTISTRY 
 
 B represents the dentin or tooth bone that has been formed by 
 the nerve or pulp; C represents the cementum or bone-Hke 
 structure that attaches the tooth to the surrounding peridental 
 membrane, D. This membrane secures it to the alveolar process, 
 F, which is the portion of the jaw-bone that supports the tooth. 
 When the gum becomes infected by microbes the inflammatory 
 exudate strips it away from the root and the intervening space 
 becomes filled with pus and tartar, which is diagrammatically 
 represented by the dots G. E represents the blood-vessels and 
 nerve-fibers extending out from the region around the tip of the 
 root. There are frequently several such openings. H represents 
 
 Fig. 44. — ^Labial aspect 
 of Fig. 43. Circle shows 
 correct spot for entrance 
 of drill into pulp canal in- 
 dicated by dotted lines. 
 
 Fig. 45. — Cross-section Fig. 46. — Method of 
 
 of tooth where pulp has squeezing novocain solu- 
 
 been just touched by a tion into the pulp by 
 
 sharp drill. pressure upon a rubber 
 
 plug. 
 
 the pulp. As before stated, the pocket of infection marked G 
 is one of the common means by which the pulp can be infected 
 without any cavity of deca}^ in the tooth itself. Infection can 
 even attack a pulp solely through germs floating in the blood. 
 
 Figure 44 represents the labiaL aspect of the tooth, the circle 
 showing the spot where the opening should be made into the 
 pulp chamber, which is shown by the dotted Hnes. 
 
 Figure 45 represents the cross-section of the same tooth show- 
 ing the opening into the pulp. This opening should be made by a 
 sharp, rapidly revolving inverted cone bur large enough not to 
 plunge into the nerve. The bur should just slice the nerve, an 
 
TREATMENT OF ROOT CANALS IIQ 
 
 operation which can be done with very Httle pain to the patient. 
 When the exposure of the pulp has been completed, one or two 
 crystals of novocain wet with a little adrenahn, or about one- 
 quarter of an E tablet powdered and moistened with water, 
 should be placed in the cavity in direct contact with the exposed 
 pulp. A pellet of soft un vulcanized rubber is then placed in the 
 orifice of the tooth, and firm pressure is made upon it with any 
 blunt instrument (Fig. 46) so that the rubber shall be driven 
 well into the cavity, thus driving the novocain into the substance 
 of the pulp. This will be a painful procedure in direct proportion 
 as the circulation in the pulp has been destroyed by infection. 
 If there is fairly good circulation in the pulp, the slightest pres- 
 sure will squeeze in sufficient of the local anesthetic to completely 
 deaden sensibility, inasmuch as any quantity that is forced in 
 will be immediately distributed by the blood circulation through- 
 out the entire pulp substance. If, however, the circulation is 
 entirely lacking through excessive congestion or calcic infiltration, 
 the local anesthetic must be forced into the pulp by pressure 
 alone, and this causes much more pain. In general practice it is, 
 therefore, wise under the conditions stated to give a firm, sharp 
 punch on the rubber and maintain the pressure. Ordinarily there 
 will be practically no pain, and if there is excessive congestion 
 and pain cannot be avoided, the sooner it is over the better. In 
 extreme cases if the pulp can only be anesthetized for a short 
 distance, and there proves to be great sensibihty underneath, 
 the point of a hypodermic needle may be inserted into the dead- 
 ened area of the pulp and the rest of the pulp injected with the 
 anesthetic. This can usually be accomplished with very Httle 
 pain, as the injection opens up the congested blood-vessels which 
 the pressure alone had tended to compress. Before insertion, the 
 point of the h3^odermic needle should be ground off to an angle 
 of 45 degrees, as the ordinary long point would necessarily run 
 well into the sensitive area, which w^ould, of course, defeat the 
 entire purpose of the procedure. 
 
 There are two objections that can be raised against this 
 method of pulp anesthesia: first, the pain, which, however, is 
 not ordinarily more than passing discomfort; second, the possi- 
 
I20 MODERN DENTISTRY 
 
 bility of forcing infection through the tip of the root. The danger 
 of spreading infection through the tip is ordinarily negligible, 
 as infected pulps in a large percentage of cases have partly 
 infected the area just outside the tip of the root by which a 
 certain toleration may already have been established, and any 
 infection forced out by the procedure just described will readily 
 be taken care of by the blood-serum in the peridental membrane. 
 At least that has been the author's experience. Of course, if a 
 thoroughly putrescent pulp is subjected to this procedure, enough 
 infection may be forced out to cause an abscess, the bacterial 
 resistance of the parts being overwhelmed. But even in such a 
 case it is astonishing how much infection the tissues at the 
 tips of infected roots can accept without forming an acute ab- 
 scess. If, however, an acute abscess does start, an aqueous 2 
 per cent, solution of carboHc acid should be forced through the 
 tip of the root after the pulp has been removed, and if this fails 
 to control the inflammation, the gum on the outside, opposite 
 the tip, should be at once injected with novocain and an opening 
 made through the alveolar plate so as to relieve the inflamma- 
 tory pressure. This is a sure means of aborting an abscess. 
 However, as before stated, when there is reason to suspect great 
 resistance to the entrance of novocain, or a spreading of infection 
 from pressure through the root foramen, the method described 
 for injecting the periosteum at the tip of the tooth is to be pre- 
 ferred. In fact, if there is resistance to anesthesia by pressure, 
 the infiltration or nerve-blocking method should be used as an 
 auxiliary assistance. 
 
 Removal of the Dental Pulp. — When the pulp has been 
 deadened we have usually about half an hour to remove it be- 
 fore it regains sensibility. A bur should thoroughly cut away 
 the bony covering of the pulp, and then a fine piano-wire engine 
 drill should be plunged to the bottom of the canal until it jams 
 (Fig. 47). This will cut off the circulation and nerve connection 
 with the tissues outside of the tooth, and will make it possible, 
 by gradually using larger and larger drills, to thoroughly excavate 
 not only the pulp itself but a large percentage of the decompos- 
 able tissue in the dentin, since the dentin lying next to the pulp 
 
TREATMENT OF ROOT CANALS 
 
 121 
 
 contains by far the greatest proportion of organic tissue. If, 
 therefore, the canal is enlarged well into the surrounding dentin, 
 about nine-tenths of all the soft organic material will have been 
 removed from the tooth bone, and consequently there will be 
 just so much less risk of later decomposition and discoloration 
 (Fig. 48). 
 
 The greatest advantage of anesthesia over the old arsenic 
 method of devitalization lies in the fact that with novocain 
 anesthesia the dentin is not killed, and can be still nourished by 
 the peridental membrane through the cells of the cementum 
 and the interglobular spaces. After pulps have been removed 
 
 Fig. 47. — Showing the use of a fine 
 canal drill in cutting off the tip of the 
 pulp at the apical foramen. 
 
 Fig. 48. — Diagram of a tj^pical 
 single-rooted tooth with pulp canal 
 reamed out for filling. 
 
 by such anesthesia in some rare cases sensibility of the dentin to 
 the touch has been noticeable for a year or two. Such nerve 
 sensations could only have come by way of the cementum and 
 interglobular spaces. It is true that not over 5 or 6 undoubted 
 cases of such a character have come to my notice during the last 
 twenty-five years, but these are sufficient to convince me that a 
 tooth without its pulp may be a living tooth nourished in all 
 parts. 
 
 Tooth Nutrition by the Peridental Membrane. — Recent 
 experiments on guinea-pigs by Dr. Gies, of Columbia University, 
 show that a blue dye, injected into the abdomen of a guinea-pig, 
 in a few days will be found to have stained the entire substance 
 
122 MODERN DENTISTRY 
 
 of the teeth blue — enamel, cementum, dentin, pulp, peridental 
 membrane, and gum. The saliva did not show the stain, so the 
 enamel must have been stained from within through the dentin. 
 This even occurred, although to a lesser degree, when the pulp 
 was removed, which would seem to indicate that even the 
 enamel can be reached by the blood-serum through the peri- 
 dental membrane, cementum, and dentin. Further experiments 
 on this subject are in progress. 
 
 The author emphasizes the possibility of a tooth deprived of 
 its pulp being nourished, and he deplores the general tendency 
 to call such a tooth dead. If a tooth becomes infected it may lose 
 all gum attachments and die, but a tooth deprived of its pulp 
 may still contain hving cementum, dentin, and enamel, all of 
 which can be nourished by the healthy peridental membrane. 
 Such a tooth is very much alive, and should not be looked upon 
 as dead, but as a living member, capable of performing its 
 valuable functions. 
 
 The anesthesia method, since it allows any remaining pulp 
 to regain sensibihty, makes it possible to discover and properly 
 treat minute canals that otherwise might have been overlooked 
 if the tissue had been permanently destroyed by arsenic. This 
 is particularly the case with multiple-rooted teeth, which point 
 will be dwelt upon later. 
 
 Root Canal Preparation. — The pulp having been removed 
 from the canal and the canal enlarged, the pulp chamber should 
 then be as carefully sterilized as though the removed pulp had 
 been putrescent. The failure to do this will cause an abscess 
 that otherwise would not occur. 
 
 The Beutelrock drills, as shown in Fig. 49, are invaluable, 
 especially where the canal is extremely small. Care should be 
 taken to use the smallest drill first, and then follow up with the 
 next size, until the canal is as large as desired. If the larger drills 
 are used first, followed by the smaller, the point of the drill may 
 become deviated from the true course of the canal, and an open- 
 ing made in the side of the root, as in Fig. 50. Experience will 
 teach the student that all root canals are not as large or self- 
 evident as the canals shown in most of the published diagrams. 
 
TREATMENT OF ROOT CANALS 
 
 123 
 
 
 W 
 
 (nz^n;. 
 
 az3^ 
 
 (IZ3:G 
 
 (EJQ 
 
 (C^ 
 
 (TJG 
 
 e::^ 
 
 n:^ 
 
 CjE 
 
 0= 
 
 CZE 
 
 
 CE 
 
 They are very often infinitesimal, and show such incalculable 
 variations, from large to minute diameters, that only the greatest 
 care can give consistently good results. 
 
124 
 
 MODERN DENTISTRY 
 
 Sets of valuable reamers and broaches are shown in Figs. 
 51 to 53. 
 
 Sterilization and Root Canal Filling. — The methods recom- 
 mended for sterihzing the canal after the pulp has been re- 
 moved are so numerous that only one or two will be described. 
 When the canal has been opened and mechanically cleansed of 
 its pulp a drop of half formahn and half tricresol, freshly mixed 
 for each treatment, is flowed in. A small plug of cotton is then 
 inserted and the orifice dried and sealed with a covering of soft 
 phosphate of zinc cement. This forma- 
 lin-tricresol antiseptic mixture was first 
 recommended by Buckley. It is ex- 
 tremely effective, especially if used with 
 a cement seal, as the heat of the body 
 causes formaldehyd gas to be liberated 
 and driven through all parts of the 
 tooth, and even through the tip into the 
 adjacent parts, causing a complete dis- 
 infection and deodorization of the tooth 
 without discoloration. The author finds 
 it better to mix formalin and tricresol 
 fresh each time, as it has been his expe- 
 rience that the formahn and tricresol 
 when mixed together in stock solution 
 tend to discolor the tooth. When 
 there is sensibiHty at the tip after the 
 pulp has been removed, it is wise to 
 allow the dressing to remain until such sensibility to pressure or 
 mastication has completely disappeared, even it if takes two or 
 three weeks. Within a week of the time that the final root-canal 
 filhng is to be inserted, the tooth should be opened and again 
 treated with the formahn mixture in the same way. If the second 
 treatment is accepted without sensibility developing during 
 the first twenty-four hours, and all odor of putrescence is absent, 
 the tooth should be filled as follows: A napkin, cotton roll, or 
 a dam should be appHed and the tooth dried with a warm air- 
 blast, great care being taken to see that the canals are free from 
 
 Fig. 50. — Diagram of 
 an accident caused by using 
 a large rigid drill to open 
 the canal. The smaller 
 drill found the pocket in 
 the side of the canal and 
 made a false opening at a 
 instead of cleansing the 
 true opening at the apical 
 foramen. 
 
TREATMENT OF ROOT CANALS 
 
 125 
 
 moisture. Then thick, syrupy chlora-percha should he gently 
 flowed to the tip of the canal and suitable gutta-percha cones 
 
 Fig. 51. — Barbed piano- 
 wire broach, originally called 
 the Donaldson nerve broach. 
 
 Fig. 52. — Kerr tapered canal reamers. 
 
 I\ 
 
 H d 
 
 Fig- S3- — Gates-Glidden drills. 
 
 inserted, and with a pumping motion gently worked as far into 
 the canal as possible, care being taken not to force the liquid 
 gutta-percha beyond the foramen. 
 
126 MODERN DENTISTRY 
 
 But when there is the sHghtest danger of forcing the liquid 
 gutta-percha through the tip of the root it is advisable to fill 
 the canal with eucalyptus oil and then insert a gutta-percha cone. 
 When this has been allowed to remain in position for a minute 
 it can be forced up into position near the canal foramen and the 
 interstices will be filled with the gutta-percha dissolved in the oil. 
 With this method there is the minimum danger of forcing the 
 gutta-percha beyond the root canal, and therefore it is frequently 
 to be preferred, as it is better to only partially fill a steriHzed 
 canal than to project the filling through the tip. The principal 
 thing to remember is that the canal must be sterile when it is 
 filled. When this procedure has been carried out the gutta- 
 percha should be packed into place with a warm instrument 
 and the exterior opening filled either with silicious cement, gutta- 
 percha, or any other filling material that seems appropriate. 
 When the pulp is dead and putrescent it is always wise to place 
 a drop of the formalin-tricresol mixture within the tooth and seal 
 it up with cement for at least twenty-four hours prior to working 
 on the root canal or canals. This must not be done if the tooth is 
 sensitive to pressure or the peridental membrane is actively 
 inflamed. To do this will increase the trouble by imposing the 
 expanding gas on the infected, irritated tissues. When there is 
 sensibility to pressure, indicating the incipient formation of an 
 abscess, a tooth should merely be opened with a drill and appli- 
 cations of iodin made to the surrounding gum. In a large major- 
 ity of such cases the inflammation will subside in a few days 
 to the point where the antiseptic mixture will be easily borne, 
 and the procedure just described can be carried out. No root 
 canal should ever be sealed up permanently so long as there is 
 the slightest odor of putrescence. The application of formalin and 
 tricresol will always be effective in removing such a condition. 
 
 Calahan Method. — When the root canal is very difficult to 
 find, 50 per cent, aqueous sulphuric acid should be apphed, and, 
 if possible, sealed within the pulp chamber. On the following 
 day the root canal will be shown by a small softened discolored 
 spot, while the surrounding dentin or tooth bone will be white 
 and clean. If, however, there is sensibility at the tip of the root 
 
TREATMENT OF ROOT CANALS 1 27 
 
 the pressure of the carbon dioxid liberated by the action of the 
 sulphuric acid on the carbonate of calcium in the tooth will be 
 too great to permit seahng the acid within the cavity. Under 
 these circumstances it is sometimes of value to work the acid 
 into the pulp chamber with a small piano-wire probe, afterward 
 washing out the free acid with a bicarbonate of soda solution. 
 This will ordinarily disclose the location of the root canal, 
 which can then be treated in the usual way. It will be noted 
 that it is recommended to work up into the root canal as far as 
 possible, because it is not always possible to fill all the fine root 
 canals to the tip. In fact, the root canals frequently have three 
 or four openings on the root, some at the tip and some at the 
 side, and those who claim that they always fill all the root canals 
 to the tip prove themselves by such a statement ignorant of 
 the difficulties to be encountered. Frequently when the pulp 
 canal has become infiltrated with Hme salts, observation will 
 not locate it. Under these conditions a fine, sharp piano-wire 
 explorer should be dug into the dentin all over the floor of the 
 pulp chamber, and this, in many instances, will locate the pulp 
 canal that otherwise would be completely masked by the white, 
 soft, calcic infiltration. Such an opening can then be entered by 
 a thin piano-wire drill. If, as before stated, the sensibility at 
 the tip will not allow the formalin-tricresol mixture to be sealed 
 within the tooth, it may be left open, protected only with a Hght 
 padding of carbolic acid and cotton. Sometimes when the bac- 
 terial resistance of the patient is so low that it seems impossible 
 to close the tooth without causing the chronic inflammation at 
 the apex of the root to become acute, it will be found good practice 
 to seal carboHc acid or tricresol and cotton in the root canal 
 with cement, and then to immediately make an opening in the 
 side of the tooth with a small drill into the pulp chamber to 
 eliminate the possibiUty of gas pressure (Fig. 54). This will 
 obviate any lack of drainage and wiU enable the tooth to slowly 
 recuperate. Such an opening should always be made when 
 acute sensibility of the tip makes it advisable to eliminate gas 
 pressure. If, as sometimes happens, the inflammation persists 
 in spite of this vent, and counter-irritation on the gum is unavail- 
 
128 
 
 MODERN DENTISTRY 
 
 ing, electrolysis with the negative pole of a dry cell battery in 
 series will be valuable in allaying the pain, as is described in 
 Chapter III. If this does not prove completely effective, an 
 opening should be made through the side of the alveolar plate, 
 exposing the tip of the root. The opening at the tip of the root 
 should be enlarged if necessary, and the root filled thoroughly 
 through the tip. The root tip with the protruding gutta-percha 
 should be smoothed with a bur. At the same time any bone 
 found in the alveolar plate lacking its full vitality should be 
 thoroughly bored away. This process 
 will be more fully described later in the 
 chapter. 
 
 Emetin. — When a root canal has been 
 filled with gutta-percha and a sensibility 
 develops, I grain of emetin hydrochlorid, 
 injected intramuscularly four or five 
 days in succession, will often be of great 
 service in allaying the symptoms. The 
 patient should also be required to take 
 I ounce of epsom salts. This latter by 
 depleting the blood-serum will greatly 
 assist in reducing any inflammatory 
 tendency, while the emetin, possibly by 
 sensitizing the germs at the tip of the 
 inflamed root, will enable the blood- 
 serum to more readily dispose of them. I mention this 
 possibility because I think it a more probable theory than 
 the supposition that the ameba could be responsible for such 
 inflammatory areas, since such areas are usually cut off from the 
 mouth, and it does not seem credible that the ameba could reach 
 them through the blood-stream. It is also good practice to give 
 calomel where there is an inflammatory tendency, as the hver 
 is much more efficient in combating infection when it has been 
 relieved of any engorgement that is likely to exist under such 
 conditions. 
 
 Canal Variations. — In dealing with single-rooted teeth one 
 sometimes finds that there are two or even three canals that 
 
 Fig. 54. — A, Cement 
 seal; B, cotton antiseptic 
 dressing; C, vent which al- 
 lows drainage or the escape 
 of gas that may not be en_ 
 dured by the inflamed tip. 
 
TREATMENT OF ROOT CANALS 
 
 129 
 
 should be opened and mechanically cleansed. It sometimes 
 happens that the root without any warning will curve sharply, 
 forming a complete right angle, as in Fig. 55. Such a condition 
 makes it all but impossible not to perforate the tooth at A in an 
 attempt to cleanse the canal, and makes it mechanically quite 
 out of the question to cleanse the canal beyond the sharp angle. 
 Where it is possible to diagnose such a condition with the a;-ray, 
 some dentists recommend seaKng up sul- 
 phuric acid in the tooth. This is sup- 
 posed to burn the pulp sufficiently to 
 permit of its being washed out with a 
 solution of carbonate of soda, and the 
 canal can then be filled with hquid 
 gutta-percha or oxyphosphate of zinc. 
 This procedure is more theoretically 
 than practically possible. There is al- 
 ways the possibihty that such a distor- 
 tion exists, and there is absolutely no 
 means but the x-ray for diagosing such 
 a condition. It almost invariably hap- 
 pens, however, that under such con- 
 ditions an apical abscess eventually 
 
 develops and, therefore, if a tooth does not heal properly the 
 x-ray should always be used, and will be an invaluable guide 
 for operative procedure. 
 
 If this is so concerning single-rooted teeth, how much more 
 so is it with multiple-rooted teeth showing abnormalities! One 
 such case was that of an upper second bicuspid that had three 
 roots when there is ordinarily but one, and three root canals, 
 only one of which canals was found and filled. Before the days 
 of x-rays how many such anomalies have escaped me and have 
 spread infection, the shade of ^sculapius only knows. Another 
 case was that of an upper central incisor that had two roots and 
 two canals. The unfilled canal naturally continued to spread 
 infection and the tooth eventually had to be extracted. When 
 we consider molars any one of which may have only one large 
 canal, bifurcated or not bifurcated, or may, by chance, have 
 9 
 
 Fig- 55- — Diagrammat- 
 ic illustration of a not infre- 
 quent condition at the tip 
 of a root. 
 
130 MODERN DENTISTRY 
 
 four, five, or six canals, the man who says that in every instance 
 he finds and fills all of these canals to the tips of the roots is so 
 optimistic that he makes himself ridiculous. This same man, 
 who claims to have such perfect technic in filling root canals, 
 almost invariably claims that he never breaks off a probe or 
 root canal drill during the process of canal excavation. Such 
 an accident, though lamentable and to be avoided, will occur to 
 the most skilful, and the man who never runs the risk of breaking 
 off a delicate drill in a canal, of necessity, has not the courage to 
 properly cleanse the canals. Our dental technic is too good and 
 skilful to require evasions or mendacity as a protection. Better 
 by far that the very occasional tip of a root should be amputated, 
 or even a tooth extracted, than to condemn all teeth to a probable 
 danger of infection through timidity in canal cleansing. The 
 conscientious, frank dentist knows his unavoidable percentage 
 of failures; he can only reduce the failures to a minimum by 
 realizing and appreciating them, not by denying and ignoring 
 them. He knows that central and lateral incisors and canines, 
 upper and lower, nine hundred and ninety-nine times out of a 
 thousand, have only one root canal, which is usually straight 
 and can be successfully filled to the tip. He knows that the 
 upper first bicuspid ordinarily has two canals, and these two 
 canals can ordinarily be successfully filled. The upper second 
 bicuspid and the lower first and second bicuspids ordinarily have 
 one canal. Any of these teeth may have additional roots and 
 canals, and any of these canals may turn suddenly, making 
 complete filKng impossible, and yet the dentist can only use 
 judicious cutting and caution. To do otherwise would mean 
 an incalculable waste of tooth structure and time. It would 
 mean a great increase in the openings made through the sides of 
 root canals into the gum; for when the root canals have been 
 properly reamed out all extra cutting merely weakens the tooth 
 and increases the danger of puncturing the cementum. In the 
 same way the dentist knows that the upper and lower first 
 molars ordinarily have three canals, but they may have only 
 one or two, or they may have four or five. He is between Scylla 
 and Charybdis; if there is only one and he hunts for more, he 
 
TREATMENT OP ROOT CANALS I. 3 1 
 
 uselessly sacrifices the tooth. If he finds three and thoroughness 
 makes him rashly hunt for more, for the one time he succeeds 
 in finding the canal he has a hundred failures, and, in reality, 
 the fine hair-like canals ordinarily do not cause irritation that 
 the peridental membrane cannot control. In exploring for root 
 canals the dentist cannot do better than follow the technic of 
 Flagg and his successors, which is about as follows : When a tooth 
 is opened into the pulp chamber the roof of the pulp chamber 
 should be completely removed and the floor burred until the 
 body of the nerve is completely removed and the canal or canals 
 are in plain view. Then at least he should use every effort 
 to find all the canals that are ordinarily present. With single- 
 rooted teeth there must be one canal at least; in reason, let him 
 look carefully for more. Sometimes he wiU not be able to find 
 even that one. In bicuspids it should be remembered that two 
 canals are not uncommon, and he should see to it that the floor 
 of the pulp chamber is thoroughly exposed, cleansed, and explored. 
 After that let him fill the canals that are found and leave the 
 rest. With the molars he should cut freely and thoroughly to 
 expose to view the floor of the pulp chamber. With first molars 
 let him expect three canals, and not be nonplussed if he finds 
 four or five; neither let him condemn himself too harshly if care- 
 ful exploration reveals only one or two, lest by too thorough 
 searching he perforates the side of the canal into the gum outside 
 and thus finds a few that do not exist. With second molars 
 three canals are the rule, although they are often difficult to 
 demonstrate. With third molars it is to be remembered that there 
 may be one canal the size of a stick of Itahan spaghetti, or there 
 may be four, five, six, or seven of a hair-Hke quahty, to dis- 
 cover which would require the "milHon magnifier eyes" so elo- 
 quently disclaimed by Mr. Samuel WeUer. With some of these 
 the skiagraph will only show that the tips have not been reached 
 and will not reveal whether bone infection is or is not going to 
 develop. If such infection should develop it will not be shown 
 by the x-ray plate until six months or a year has passed. All 
 the dentist can do is in every instance to follow the rules and do 
 
132 MODERN DENTISTRY 
 
 his best, and not bore his fellow-workers with claims of perfection 
 in technic. 
 
 In filHng large, obvious canals it is wise to use oil of eucalyp- 
 tus and a cone of gutta-percha. Oil of eucalyptus should be 
 pumped in first, then the gutta-percha cone inserted and worked 
 slowly up and down until it settles as near the bottom of the 
 canal as possible. It should be allowed to soak up the excess 
 eucal3^tus for a minute or two, and then with a hot instrument 
 pushed home and more gutta-percha added until the canal is 
 fiUed. And each time the conscientious dentist does this, he 
 prays that it has filled the canal to the cementum, and also that 
 neither the cone nor the liquid gutta-percha has been forced 
 through the tip. The cementum being actively aHve will fre- 
 quently satisfactorily close up an aseptic apical foramen if the 
 gutta-percha does not extend beyond it into the soft tissues. 
 The only way to be certain that the root canal is completely 
 filled is to boldly push the gutta-percha through the tip, and then 
 to smooth it off with a bur by going through the alveolus from 
 the outside of the gum. The method of preparing and filling 
 root canals just described almost invariably gives good cHnical 
 results, but when it fails and chronic inflammation at a root tip 
 shows that the gutta-percha filling is not acting as a satisfactory 
 protection, the tip should be excised or the root extracted. 
 With the smaller, thread-like canals thin oxyphosphate of zinc 
 makes an excellent filling, since it can readily be pumped into 
 place with a hair-like broach, and if a little excess does escape 
 through the root the excess is absorbed, although not without 
 some pain. However, when the pain goes, there is seldom any 
 bad after-result. When there is a distinct tendency for irritation 
 to persist at the tips of the roots a very small portion of iodoform 
 can be placed at the tip before the gutta-percha is inserted. 
 Great caution should be observed in using iodoform in a front 
 tooth, as when used in any quantity it causes a stain to develop 
 that it is practically impossible to remove. Paraffin and other 
 similar semiliquid materials have been used for filling root 
 canals, but they are apt to be absorbed, leaving the canals 
 unprotected. 
 
TREATMENT OF ROOT CANALS 133 
 
 Bleaching. — Before we leave the subject of root canal steril- 
 ization and filling it must not be forgotten that tooth discolor- 
 ation may enter as a factor of considerable importance. This 
 discoloration has to be \iewed both from the hygienic as well as 
 the cosmetic point of view. Tooth discoloration may come from 
 purely chemical causes, such as amalgam salts, nitrate of silver, 
 iodoform, or any of the essential oils commonly used in the treat- 
 ment of root canals, or the discoloration may be due to pulp 
 deterioration. This latter discoloration appears first as a faint 
 yellow cloudiness, and as the pulp further loses its vitahty and 
 finally dies, this cloudiness may progressively change to a dark 
 brown or a grayish black. 
 
 Discolorations due to a chemical or purely mechanical cause, 
 while distressing, are not a pathologic danger sign; but discol- 
 orations caused by pulp infection and infiltration into the tooth 
 substance are not only unsightly, but a menace to the general 
 health of the patient. And yet it is not always an easy matter to 
 decide which type of discoloration is presented to us. It may be 
 a combination wherein the tooth has started to discolor through 
 pulp deterioration, and has been assisted along its uncosmetic 
 path by pulp-canal dressings such as iodoform or oil of cloves. 
 Such chemical discolorations cannot be bleached by any known 
 materials. When such a discoloration occurs the best bleacher 
 is the bur or stone that cuts out the discolored tooth substance 
 and makes room for a suitable porcelain or cement restoration. 
 But where there is the possibility that the discoloration may 
 also arise from previous pulp decomposition and infiltration 
 throughout the tooth, the root canals should be carefully treated 
 and the tips filled as just described. Thorough attempts at 
 bleaching should then be inaugurated, whether they prove 
 successful or not, for the process of restoring the natural color 
 to a tooth discolored by pulp infection is accomplished by act- 
 ually oxidizing and destroying the putrescent substance of the 
 pulp that has permeated the tooth; and therefore, even if the 
 bleaching process is not able to remove the chemical stain, it is 
 nevertheless hygienically of the utmost value. For if the crown 
 of a tooth blackened by the infiltration of pulp infection is merely 
 
134 MODERN DENTISTRY 
 
 cut off and replaced by a suitable porcelain substitute, the 
 infection in the root may and probably will continue to grow, 
 because all the germ food on which the infection could subsist 
 is still present, ready for the nourishment of any stray germs that 
 may possibly have escaped the antiseptics, or may later obtain 
 entrance through a defectively filled apical foramen. 
 
 Therefore, tooth discolorations that arise from the death of 
 the pulp and the infiltration of the infected mass into the inter- 
 stices of the tooth should not be tolerated. This discoloration 
 is not merely unsightly, it is a source of deterioration that in 
 time will actually undermine the stability and usefulness of the 
 tooth, and the dentist who does not appreciate the danger is 
 probably not thorough in his steriHzation, and thus the slowly 
 decomposing material will be sealed within the tooth substance, 
 and the gas that is formed will slowly and surely drive the de- 
 pressing bacterial toxins through all parts of the tooth and even 
 out into the body at large. Thus the peridental membrane 
 when attacked by actual infection from within is so weakened in 
 its bacterial resistance that it readily accepts any infection that 
 may be either floating in the blood-stream or attempting to gain 
 an entrance at the gum margin. 
 
 The two bleaching agents most valuable in the treatment 
 of discolored teeth are a 30 per cent, aqueous solution of peroxid 
 of hydrogen and a saturated aqueous solution of oxaHc acid. 
 If the iron of the hemoglobin has darkened the tooth, as is indi- 
 cated by the presence of the brown stain, it is wise to use the 
 oxalic acid alternately with the peroxid, but if the tooth has a 
 gray or black discoloration and has not been stained with amal- 
 gam or previously treated, peroxid alone will usually be able to 
 permanently restore the tooth to its normal color. 
 
 The method of using these two bleaching agents is as follows : 
 The root canal or canals should be sterilized with tricresol and 
 formahn freshly mixed. Then one or two drops of 50 per cent, 
 aqueous solution of sulphuric acid should be placed within the 
 pulp cavity, where it should be allowed to remain for a few min- 
 utes. It should then be neutralized with a concentrated aqueous 
 solution of bicarbonate of soda. This will cause the formation 
 
TREATMENT OF ROOT CANALS I35 
 
 of carbon dioxid at the further ramification of the dentin tubes, 
 which will tend to sweep out any loose, decomposed material 
 that may be present. The sulphuric acid is also a powerful 
 germicide, and such an application seems to have no harmful 
 effect if it is not repeated too often, and if it is not allowed to 
 remain upon the outside surface of the enamel of the tooth. 
 When the tooth has been sterilized and the loose discoloration 
 has been removed from the pulp chamber and its environs by 
 the mechanical means of the gas formation, and the tips of the 
 canals have been thoroughly sealed with a pellet of gutta-percha, 
 the actual bleaching may be attempted. But it must be remem- 
 bered that it is just as necessary for the root under the gum to 
 be bleached as it is for the tooth crown, if permanent results 
 are to be secured; for any discoloration that is left anywhere 
 within the tooth, especially within the pulp canal, will tend to 
 become infiltrated throughout the entire organ. Therefore 
 the tip of the root should be sealed, and as much of the canal as 
 possible should be left open to the action of the bleaching agents. 
 The best way to do this is to fill the canal completely with gutta- 
 percha during one visit, and then on a later occasion, when 
 the gutta-percha is absolutely hard, to drill it out almost to the 
 apical foramen, leaving the tip completely sealed. It is particu- 
 larly necessary for the tip to be sealed completely when bleaching 
 is undertaken, for if the bleaching material is forced up through 
 the tip into the gum an acute abscess is likely to be the result. 
 Let us recapitulate : The root canal has been opened mechan- 
 ically, cleansed, and sterilized. It has been flooded with 50 per 
 cent, sulphuric acid, washed out with bicarbonate of soda, and 
 the end of the root has been sealed. When this has been done 
 the root canal should be carefully dried and a twist of cotton wet 
 with a saturated aqueous solution of oxalic acid should be in- 
 serted, and then a small electric cautery (see Fig. 25) should be 
 heated to a point just below redness and plunged into the pulp 
 cavity, vaporizing the oxalic acid solution. The cotton dressing 
 should be removed when it is dry and the process repeated 
 several times. Finally, the oxaHc acid and cotton should be 
 temporarily sealed tightly within the pulp chamber with cement 
 
136 MODERN DENTISTRY 
 
 and the patient dismissed. The amount of acid used is so small 
 that there is no danger even if the solution escapes into the 
 mouth through a defective seal of the cavity. When the patient 
 returns on the following day the same procedure should be 
 carried out with the 30 per cent, peroxid of hydrogen solution. 
 The peroxid is particularly effective as a bleacher when it is 
 converted into steam within the pulp cavity, since the oxygen 
 thus liberated is free atomic oxygen, which attacks the organic 
 discoloration not merely as molecular oxygen would, but it 
 attacks it with all the force that is usually expended by the 
 atoms in uniting within the molecule. When the tooth has 
 been steamed from within several times, cotton wet with peroxid 
 should be sealed in the canal with cement, and then the outside 
 of the tooth gone over with the hot instrument. This heat 
 liberates the nascent oxygen under pressure and causes a sudden 
 whitening of the tooth substance that is most satisfactory and 
 effective. If, under these conditions, the apical foramen of the 
 canal has not been carefully sealed, the oxygen escaping from 
 the solution may cause an abscess by rupturing the tissues 
 on the outside of the tooth. With oxalic acid the danger does 
 not exist to such an extent. When this sealing and external 
 ironing has been done several times, the solution can be sealed 
 within the tooth for a week or more with the expectation that 
 the heat of the body will slowly liberate the oxygen, causing a 
 still further antiseptic and bleaching effect. At the end of each 
 operation, prior to the final filling, the pulp canal should be 
 flooded with hot water to wash out the soluble iron salts. 
 
 Sometimes when the peridental membrane is particularly 
 sensitive the pressure of the gas through the tooth substance 
 may cause an external irritation. This has happened very 
 occasionally in my experience, and when it does occur it is wise 
 to put a slight vent in the cement seal so as to temporarily 
 relieve the pressure. 
 
 When stains occur on the outside of the enamel of a tooth 
 with a living pulp the external steaming process, just described, 
 can be effectively used on the enamel if the tooth is not over- 
 sensitive to heat. 
 
TREATMENT OF ROOT CANALS I37 
 
 The details by which the mouth and Hps are protected from 
 injury or irritation by napkin or rubber-dam have not been dwelt 
 upon, as this is a commonly understood dental procedure. 
 
 Root Amputation and x-Ray Diagnosis. — Let us now take up 
 the question of root amputation, preserving a part of a tooth 
 by excision either of the tip of the root, or in the case of molars, 
 by removing the necrosed roots, leaving the healthy root or 
 roots as a useful support for filhng or crown. 
 
 Amputation of roots should be preceded by a careful x-ray 
 study of the region involved. Emphasis is laid on the word 
 careful as applying both to the method of taking the x-ray and 
 to its interpretation in conjunction with the cHnical facts. The 
 darkened area at the tip of a root, as shown by an x-ray plate, 
 may indicate absorption or the presence of chronic inflammation 
 of the bone, or a thickened peridental membrane. The too clear 
 differentiation of a root tip in the alveolus is just as significant 
 of lost vitaHty, but as bones and roots vary in density, it is not 
 always easy to differentiate and diagnose a case of this character. 
 Therefore, when it comes to saying, by x-ray alone, whether a 
 pyorrhea pocket is getting well and has ceased spreading in- 
 fection, or is increasing so as to be a menace to the health of 
 the patient, the x-ray man is helpless, and frequently makes 
 himself ridiculous if he does not allow caution to temper his 
 enthusiasm. 
 
 The following is a case in point: A young married woman 
 had been under treatment for gum infection and loose teeth 
 during a period of six years, and had showed marked improve- 
 ment. The gums had healed, the pus had ceased to flow, and 
 the teeth had tightened. There was unquestionably progressive 
 improvement. Many of the teeth that originally were so loose 
 that they could have been pulled out by the fingers had become 
 firm, the gums around them had assumed a healthy color, and 
 the pockets of infection had disappeared. There were two or 
 three teeth that did not show the improvement of the rest, but 
 the mouth as a whole was becoming comfortable and healthy. 
 In the meanwhile the patient suffered from enteroptosis and went 
 to her physician, who sent her to a prominent x-ray man for an 
 
138 MODERN DENTISTRY 
 
 examination of her bowel convolutions. Incidentally, he took an 
 x-Ta,y of her teeth and reported to her physician that he did not 
 find a single healthy tooth in the upper jaw and only three in the 
 lower. This report was enthusiastically received by her physician, 
 who said that the :r-ray report was one of the most beautiful 
 and complete he had ever known, and complimented the x-ray 
 specialist very highly on the brilHancy of his report. As a matter 
 of fact, all of the teeth except three were in a fairly healthy con- 
 dition and certainly were not causing the general systemic 
 infection. Two of these three still had a good chance of heahng 
 as was later demonstrated. This was a case where it was im- 
 possible to interpret the x-ray of the mouth correctly without 
 knowing the clinical facts and history of the case. 
 
 Perhaps, then, it might be wise to say that we should learn 
 all that we can by the x-ray plate, but not rely too much on the 
 finality of its data, for many a surgeon knows that two ends of 
 a bone will make a thoroughly practical union even though the 
 x-ray would conclusively demonstrate that the dressing should 
 be removed and the patient subjected to the agony of an attempt 
 to get a juxtaposition that would be only theoretically an im- 
 provement. The author does not wish to be interpreted as 
 discrediting the x-ray; he discredits the overzealous interpre- 
 tations of some x-ray men who claim that all other methods of 
 diagnosis are to be subservient to their valuable but, in reality, 
 limited scope of vision. 
 
 The method of procedure in the amputation of the necrotic 
 tip of a root follows. Figs. 56, 57 representing any typical single- 
 rooted tooth: 
 
 A 2-c.c. hypodermic syringe is filled with a 0.5 per cent, 
 solution of novocain and suprarenin. lodin should be appHed 
 over the places to be punctured. The lip is retracted and the 
 tip of the needle is inserted beneath the periosteum near the tip 
 of the root on the labial side. The 2 c.c. are then injected and 
 the same procedure is carried out in the lingual surface. A i per 
 cent, solution may be used and half the amount injected on each 
 side if desired. If this is done properly, at the end of five min- 
 utes the surrounding parts should be white and insensitive. 
 
TREATMENT OF ROOT CAXALS 
 
 139 
 
 Then an opening is made through the gum with a sharp knife, 
 and the periosteum loosened and pushed up with a chisel. The 
 wound is kept open by a retractor thoroughly exposing the al- 
 veolar process. In a certaia number of cases the tip of the 
 root and necrotic cavity will be exposed to view, when the tip 
 may be amputated and the dead bone removed with bone 
 drills and spoon-shaped excavators. It is especially necessary 
 that all of the dead bone and abscess sac should be removed. 
 The suprarenin makes this a practically bloodless operation. 
 
 Fig. 56. — A, Cross-section of 
 tootli; B, the lip; C, abscess in the 
 bone at the tip of the root. 
 
 Fig. 57. — Operation of root ampu- 
 tation completed: A, Tooth; B, lip; 
 C, excised abscess area; D, gutta- 
 percha root canal filling; E, unfilled 
 portion of root canal. 
 
 If the root canal has previously been sterilized and filled to 
 the tip with gutta-percha, the blood-clot can now be allowed to 
 form and the incision in the periosteum and gum can be stitched 
 together, thus completeing the operation. But if the canal has 
 only been sterilized, the point of a gutta-percha cone should be 
 pushed through the end of the root and trimmed smoothly with a 
 hot instrument. But in many instances the pushing back of the 
 periosteum and gum does not expose the root and abscess, and 
 in these cases great nicety in laying bare the root is required. 
 For instance, in Fig. 58, let the lateral incisor ^ be a tooth with 
 achronic abscess at the end of the root, as shown by dotted 
 
I40 
 
 MODERN DENTISTRY 
 
 Fig. 58. — Procedure where the alveolar plate above the abscess shown by the 
 dotted circle is unbroken. The cross lines indicate the alveolar plate. Gum and 
 periosteum are not shown. 
 
 Fig. 59. — The two cuts shown near the tip of the root of tooth A demonstrate the 
 first steps in the removal of the bony plate over the abscessed root tip. 
 
TREATMENT OF ROOT CANALS 
 
 141 
 
 Fig. 60. — The connecting line made by a chisel, at the base of the two up- 
 right cuts, shows how the alveolar plate should be divdded previous to its being 
 lifted up with the chisel. 
 
 Fig. 61. — Necrotic tip of the abscessed tooth exposed after the covering plate has 
 
 been removed. 
 
142 MODERN DENTISTRY 
 
 lines under the cross lines that indicate the overlying alveolar 
 plate. The gum and periosteum being retracted, are not shown. 
 
 Figure 59 shows two cuts through the bony plate made on each 
 side of the affected root. Then a sharp chisel with hand pressure 
 alone is pressed on the bone over the root so as to connect the 
 ends of the two cuts, as shown by the additional Hne in Fig. 60, 
 and the entire bony plate is lifted up with the chisel exposing 
 the root tip in the abscess opening of the bone as in Fig. 61. 
 When the root is exposed, if the abscess is still higher there is 
 no difficulty in working up toward it, cutting off the tip, and cu- 
 reting and imishing as just described. When complete cureting 
 does not seem possible, as is sometimes the case, the wound should 
 be packed with iodoform gauze and kept open by repeated 
 dressings until healthy granulations completely cover the bottom 
 of the wound and show conclusively that healing is progressing 
 satisfactorily. To always treat such a wound aseptically seems 
 absurd, for to make such a wound surely aseptic would mean 
 such an extension of the surgical area that much valuable tis- 
 sue would be lost and many teeth sacrificed. Therefore, since 
 at times it is hardly possible to closely differentiate between 
 dead bone and living bone with a bur, in doubtful cases it seems 
 best to keep the wound open until it is apparent that all the bone 
 is healing properly, so that all parts that do not heal can be 
 cureted until they do heal. The mouth of the wound should 
 be kept open until granulations cause the cavity to be shallower 
 than it is wide. Then heaUng will ordinarily progress to a 
 satisfactory termination. This procedure of root amputation 
 applies to all of the single-rooted teeth and the upper first bicus- 
 pid, but when we come to the molar teeth a different procedure 
 is usually necessary. 
 
 Root Excision. — ^When the buccal root or roots of the first 
 or second upper molars have become necrotic at the tip, the same 
 procedure can be used as has just been recommended for the 
 single-rooted teeth, but when the palatal root of the upper first 
 or second molars has become necrotic at the tip, complete ex- 
 cision of the root from the rest of the tooth is usually to be pre- 
 ferred. It has been the author's clinical experience that necrosis 
 
TREATMENT OF ROOT CANALS 
 
 143 
 
 or absorption at the tip of the palatal root is usually associated 
 with a pyorrhea pocket at the bifurcation of the roots. 
 
 For instance, let us suppose Fig. 63 represents a superior 
 first molar. A represents a pocket of infection in the bifurcation 
 of the roots beneath the gum which extends its influence to B, 
 which represents a necrotic tip of the palatal root; F represents 
 the crown of the tooth; C represents the palatal root; D and E, 
 the buccal roots. Such a condition usually exists when the pulp 
 has either completely died, or when it has become so infected 
 that the living pulp is causing an abscess at one of the root tips, 
 
 If 
 
 Fig. 62. — Bone drills. 
 
 usually the palatal. Volumes have been wTitten about the in- 
 struments that can curet and cure such a spot as A represents, 
 surrounded as it is by three roots, but any conscientious ex- 
 perienced dentist knows that this is a more theoretic than a 
 practical possibility. Curetting and stimulating antiseptics 
 may quiet "and mask such an abscess, but in ninety times out 
 of a hundred no treatment will cure it so that there will be 
 reattachment of the membranes to the root; and as such an 
 abscess may result in grave systemic complications, any such 
 temporizing procedure should be out of the question. The first 
 
144 
 
 MODERN DENTISTRY 
 
 step, under such conditions, is to anesthetize and remove the pulp, 
 as has just been described. When this has been done, a fissure 
 bur should be inserted between the buccal and palatal roots at 
 the point A, and a cut should be made through into the pulp 
 chamber and up to the grinding surface, as is designated by the 
 dotted line. This may either be repeated on the other side, or 
 the cut may be continued directly through the pulp chamber 
 until the crown has been completely cut in two, leaving one half 
 attached to the buccal roots and the other half to the palatal 
 root. Then the novocain mixture should be injected freely 
 about the palatal root until the gum is white and insensitive, 
 when a single pry with a spoon elevator between the adjacent 
 molar and the palatal root will extract it, leaving the buccal 
 
 Fig. 63. Fig. 64. Fig. 65. Fig. 66. Fig. 67. Fig. 68. 
 
 Figs. 63-68 — Progressive steps by which a necrotic palatal root may be ex- 
 cised from the sound portion of the tooth, and the steps by which the remaining 
 healthy portion of the tooth may be restored to comfort and usefulness. 
 
 roots with the attached half of the crown as in Fig. 64. G rep- 
 resents exposed pulp chamber not yet prepared for filHng. Of 
 course forceps can be used to extract the root if desired, but the 
 elevator usually gives the best results. The pulp chamber and 
 canals in the buccal roots should now be sterilized with formalin 
 and tricresol and cut out and filled. If the attached portion of 
 the crown is sound and undecayed it can be dovetailed as in 
 Figs. 65 and 66 and filled with any filling material or with an 
 inlay (Fig. 67), so that when it is completed it will resemble 
 Fig. 68. It will then resemble a large, plump, useful bicuspid 
 with two roots, turned on its side. Such a tooth will give excel- 
 lent service in the mastication of food, and as regards looks, 
 from the outside it appears just as before, since the buccal cusps 
 have not been altered. Where the crown is decayed or missing 
 
TREATMENT OF ROOT CANALS 
 
 145 
 
 the remaining roots should be restored with amalgam, as de- 
 scribed in Chapter VII, and fitted with a suitable crown, either 
 of gold or platinum, with a porcelain facing. 
 
 When a buccal root of a superior first or second molar is 
 necrotic and has to be removed, somewhat the same procedure 
 should be followed. In Fig. 69, A represents a necrotic buccal 
 root, B the palatal, and C the normal buccal root, D the crown 
 of the defective tooth, and E the crown of the adjacent tooth 
 to which a sufficient contour should be made or preserved. 
 The dotted fine shows how the cut should be made so as to 
 maintain the supporting contour against the adjacent tooth E. 
 This can be made with a fissure bur in a manner similar to the 
 
 Fig. 69. Fig. 70. 
 
 Figs. 69, 70 show the method of removing a defective buccal root from an upper 
 
 molar so as to preserve the approximal contact with the adjacent teeth. 
 
 method just described, and should be done after the pulp chamber 
 and the root canals in the two sound roots have been fiUed. 
 When the root has been cut absolutely free from the tooth, 
 novocain can be used and the root can be extracted with an 
 elevator. If the crown is not perfect, and a good support against 
 the adjacent tooth is not present, the crown should be made 
 perfect with some suitable filHng. Of course, the natural crown, 
 if preserved, should be poUshed smooth with stones where the 
 root has been excised. 
 
 Figure 70 represents the crown D with the defective buccal 
 root removed. When this operation is properly completed it 
 should be possible to easily cleanse the contours of the inter- 
 dental space with floss-silk. 
 
146 
 
 MODERN DENTISTRY 
 
 When we come to the lower first and second molars the 
 procedure is the same but more simple, as here we have usually 
 but two roots. As described in the previous case, when a ne- 
 crotic root is associated with a partly living pulp, the pulp in all 
 the canals of the infected tc^oth should be removed prior to the 
 excision of the root. When this has been accomplished we can 
 proceed to the excision and removal of the necrotic root in ques- 
 tion. Figure 71 represents a first lower molar with an unde- 
 cayed crown. The anterior root A is necrosed and the pulp dead. 
 The posterior root is sound, with a living pulp. B is the crown, 
 C the pulp outline, D the spot of infection in the bifurcation 
 of the roots. 
 
 Fig. 71. Fig. 72. 
 
 Figs. 71, 72 show how the defective anterior root of a two-rooted lower molar can 
 be removed and the contact with the adjacent tooth preserved. 
 
 The abscess at the fork of the roots makes a complete canal 
 of infection underneath the tooth. Let us suppose that the pulp 
 canal has been opened and the living pulp removed. If the crown 
 is undecayed, a complete operation can be performed by insert- 
 ing the fissure bur at the bifurcation of the roots, and excising 
 the root along the dotted line E, so that the contour and approxi- 
 mation against the adjacent tooth can be retained. When this 
 has been done, the root can be pried out sidewise by means of an 
 elevator, leaving the tooth as in Fig. 72. The remaining pulp 
 canal in the posterior root can then be sterilized in the usual 
 way and the root and crown filled, care being taken to smooth 
 the filling within the pulp chamber where the root was excised. 
 Where the crown of the molar is badly decayed, the remaining 
 root should be fitted with a properly contoured crown, so that it 
 
TREATMENT OP ROOT CANALS 
 
 147 
 
 will rest securely against the adjacent tooth. This support is most 
 essential and will prevent undue tipping until the bony socket 
 of the extracted root has completely filled in and healed (Fig. 73). 
 If the root is decayed below the gum it must be fiUed up with 
 amalgam and properly contoured before it is covered by a suitable 
 crown, as described in Chapter VII. If, as sometimes happens, 
 the adjacent tooth is decayed or already has a filling, the extra 
 contour necessitated by the loss of the root can be divided be- 
 tween the two teeth, the filling being made larger, and the crown 
 being correspondingly decreased in size, as in Fig. 74. Some- 
 times we have a lower molar where the tips of the roots are 
 healthy, but the gum and alveolar process have receded to such 
 
 Fig. 73- — Diagrammatic method of 
 restoring a single molar root with a 
 crown so that the interdental space can 
 be preserved. 
 
 Fig. 74. — Same case, with the inter- 
 dental space divided between the crown 
 and the filling in the adjacent tooth. 
 
 an extent that the infection has worked completely through the 
 bifurcation of the roots, forming a channel under the tooth 
 that the ordinary daily cleansing cannot possibly reach or 
 restore to healthy condition, as in Fig. 75. 
 
 A represents the crown of a lower molar, C represents the 
 gum line, showing the recession, and B represents the spot of 
 infection and tartar in the bifurcation of the roots. The hope- 
 less future of such a molar is apparent. The gum that has re- 
 ceded cannot be restored to cover up the bifurcation, and the 
 opening will be a constant invitation for the lodgment of bacteria 
 and tartar, which will not only result in the eventual loss of the 
 tooth, but also in grave systemic infection. Such a condition 
 cannot possibly be tolerated even if the remedy demands the 
 
148 
 
 MODERN DENTISTRY 
 
 loss of the tooth. But such a sacrifice is by no means always 
 necessary. The principal need is a chance to thoroughly cleanse 
 the channel under the tooth and a chance to keep it clean, and 
 that can be accomplished as in Fig. 76. When the pulp has been 
 
 1/ 1/ 
 
 Fig. 75. — Molar with the bifurca- 
 tion of the roots exposed and infected, 
 where cleansing is impossible. 
 
 Fig. 76. — Tooth divided and con- 
 verted into two bicuspids which can 
 readily be cleansed with brush and 
 dental floss. 
 
 devitalized and the root canals filled, the bifurcation should be 
 boldly extended up through the middle of the crown of the molar 
 
 Fig. 77. — ^Two parts of tooth strapped together by a cemented staple for the 
 purpose of securing greater stability. Here the interdental space must be 
 cleansed with dental floss inserted beneath the staple by a wire needle. 
 
 until the roots are completely separated; and the separated 
 parts of the crown should be filled as though each was a bicuspid, 
 leaving a cleansing space through which the floss-silk can be 
 passed just as in any of the approximal spaces of the other teeth. 
 
TREATMENT OF ROOT CANALS I49 
 
 If there is excessive mobility a staple of platinum can be inserted 
 in the adjacent iillings so as to make them join (Fig. 77). If 
 this is done, the floss-silk will have to be passed underneath 
 the staple by means of a needle with a blunt point. The floss-silk 
 can be sHpped through the eye, the flexible needle passed between 
 the teeth that are stapled together and drawn through, carrying 
 the silk with it. The silk can then be swept over all the surfaces 
 and the bacterial deposits entirely removed. 
 
 Sometimes when the roots have been cut apart and the pulp 
 chamber is still open, it is well to put in a gutta-percha filling 
 for a month or so, in order that the mastication on the gutta- 
 percha shall spread the two portions of the divided tooth into 
 absolute contact with the adjacent teeth; thus the fillings put 
 in the two halves of the pulp chamber will have a more perfect 
 support from the dental arch. When the crown is badly decayed 
 the separate roots must be capped, as is ordinarily done with 
 single-rooted teeth. 
 
CHAPTER VII 
 
 FILLINGS 
 
 Hammered Gold. Inlays — Porcelain and Gold. Advantages 
 and Disadvantages of Cement. Silicious Cement, Amalgam, 
 and Gutta-Percha 
 
 Operative Efficiency. — Frederick W. Taylor in his scientific 
 shop management showed conclusively that there should be no 
 such thing as unskilled labor. He started on the basis that there 
 is a best way to do everything. He searched until this best 
 way was discovered, and then he saw to it that each workman 
 under his care was instructed and even compelled to use this 
 way. Thus the workmen, instead of using various methods 
 according to their individual whims, all became skilled workmen, 
 to the great benefit of their employers and themselves. By his 
 plan as simple a proceeding as loading pig-iron on a car was 
 reduced from a haphazard process to a science. The man that 
 could load only 12.5 tons of pig-iron a day when left to his 
 own devices, under scientific management readily loaded 47 
 tons in the same time. Mr. Taylor found that 21 pounds was 
 the proper weight for each shovelful for the average man if he 
 would do his best work and not become tired during the day; he 
 also showed the men the most efficient method of shoveling. Then, 
 by having shovels of various sizes to suit the kind of material 
 shoveled, he made a man carry in his shovel 2 1 pounds, whether 
 he was shoveling iron ore, coal, or sawdust. 
 
 The great value of such a plan is obvious. Dentists are suffer- 
 ing from the lack of just such training. Each teacher in the dental 
 schools is apt to advocate the methods used by his former 
 teachers, which methods are varied according to the instructor's 
 personal skiU or mechanical bias. There is no standard best 
 method which all students are taught. Some men employ 
 
 ISO 
 
FILLINGS 151 
 
 methods that will obviously give better results in one-half the 
 time. These methods should not be brushed aside as requiring 
 skill unattainable by others. They should be studied and col- 
 lected into a system that would stand as a model for all teachers 
 to use until scientific research has demonstrated a further advance. 
 In fact, the dentists of the future should be taught dentistry 
 in reference to a recognized standard, both as regards rapidity 
 and efficiency. Since we are working on living organisms, it 
 is especially necessary that no judicious means of shortening 
 the time of an operation should be overlooked. 
 
 In a surgical operation rapidity of action is a recognized 
 element of great importance. The longer the patient is kept 
 under ether, the greater is the danger from exhaustion and sur- 
 gical shock. At such a time a life may hang on the question 
 of ten minutes. Before the days of anesthetics speed was con- 
 sidered of even more importance than now. And yet some den- 
 tists perform operations on conscious patients sometimes con- 
 suming two or three hours of agonizing procedure to accomplish 
 a result that other dentists will attain in one-half the time by 
 work that is comparatively painless. Dentists will always 
 differ in their relative skill and speed, but such differences as 
 now exist can only come from defective technic. Some dentists 
 prepare cavities for filling in five minutes that other operators 
 require an hour to shape. A man will sometimes take ten or 
 fifteen minutes to adjust a rubber-dam under a sensitive gum, 
 causing great laceration of the peridental membranes, in order 
 to put in a gutta-percha or amalgam filling that ought not to 
 have taken over two or three minutes to insert with the aid of 
 the cotton roll or napkin. 
 
 The Old Hammered Filling. — For instance, what could be 
 more ridiculous than the present employment of the hammered 
 gold filling for repairing a decayed spot in a tooth? It is a long, 
 tedious, painful process to both the patient and the dentist. 
 The most skilful operator has a decided percentage of non- 
 bacteria-proof edges, and the average dentist seldom makes any 
 bacteria-proof edges at all, so that the tooth filled with ham- 
 mered gold ordinarily begins to decay as soon as the filling is 
 
152 MODERN DENTISTRY 
 
 inserted. Especially is this so if the filling is between the teeth, 
 where the mastication of food will not sweep it clean and the 
 bacterial plaques are allowed to grow upon it unmolested. 
 Apropos of the way a joint that is not bacteria-tight can be a 
 source of decay, I might mention an experience of my own 
 early days of practice. It was during my first year after grad- 
 uation that a child came to me with characteristic softening 
 of the sulci in the four upper bicuspids. The teeth were sensi- 
 tive to the blows of the hammer, and yet I cut out the four sulci 
 and inserted four shallow gold fillings. Accurate condensation of 
 the gold was impossible owing to the fact that the tips of the 
 roots had not been formed sufficiently to withstand the stroke 
 of a strong enough blow to do the work. In two years the child 
 returned, and where two of the fillings had dropped out there 
 was no decay, and where the two remaining ones were still 
 cHnging to their undercuts, well-defined decay was making 
 its insidious inroads toward the pulp. The two fillings that had 
 dropped out had fortunately done so before the decay had had a 
 chance to become intrenched in the imperfect margins, leaving 
 cavities that were shallow enough to be self-cleansing by the 
 action of mastication. Ever since that experience I have merely 
 polished out these soft sulci wherever it was possible to leave 
 them with hard, perfect cups of enamel that were self -cleansing. 
 This is always possible if the tooth is examined for such soft 
 spots as soon as it comes through the gum. It cannot be stated 
 too often that the thinnest coating of enamel is a far better 
 protection than the best filling that has yet been invented. 
 
 We constantly hear of the beautiful gold fillings with perfect 
 edges that lasted over fifty years. In speaking of such a filling 
 it is invariably intimated that with careful technic perfect fillings 
 are always possible. In my experience, however, even the den- 
 tists most skilful in making hammered gold filKngs have had a 
 high percentage of failures, and most of them frankly admit it. 
 
 I continued to put in hammered gold fillings for some fifteen 
 years, and finally even made gold fiUings that had a specific 
 gravity greater than cast gold. I have put in gold fillings that 
 have now lasted twenty-five years, and admit that probably 
 
FILLINGS 153 
 
 this is due more to the fact that the gums have receded, leaving 
 the margins self-cleansing, than to any intrinsic value in the 
 method. But such a fact does not prove in the least degree that 
 the hammered gold filling or the gold filling put in against bare 
 dentin is not now antiquated. When it is necessary to use gold 
 to resist the force of mastication it should always be put in with 
 cement as a bond between it and the tooth structure. By this 
 means a bacteria-tight joint can be insured, and every filling 
 that is inserted will faithfully perform its part of the tooth 
 preservation, whether it is inserted by expert or beginner. This 
 is especially so since the advent of the new silicious cements 
 that are insoluble in the mouth, and have a strength of substance 
 that makes them suitable for attaching fillings to the tooth 
 structure. The cement also protects the tooth from the shock 
 due to the great thermal conductibility of the gold. 
 
 Even when the only cements available were soluble in the 
 mouth, the inlay fairly won its way against the hammered gold 
 filling, both because it preserved more teeth and because it 
 avoided the long, battering strain. But now, with an almost in- 
 soluble cement available, the inlay should always be preferred 
 wherever a hammered gold filling might, in the past, have been 
 deemed advisable. In view of the fact that the silicious cements 
 are being so perfected as to insolubility, color, translucency and 
 strength of material, it is a question whether in time they may 
 not largely, if not entirely, supplant all of the other fillings, the 
 inlay itself not being excepted. In fact, this almost insoluble 
 cement, capable of absolutely matching a tooth, may sweep away 
 the necessity for a large part of the intense, mechanical refine- 
 ment that has so loaded down the dentist in the past, and give 
 him the time essential for mastering the medical aspects of his 
 work. With the hammering of gold fillings eliminated, and gold 
 inlays made in five to fifteen minutes rather than in an hour or 
 two, with crowns and bridges set in a cement that will conceal the 
 joint of the porcelain, and fillings made boldly above the gum 
 because the color of the teeth can be matched, two-thirds of 
 the mechanical drudgery of the dental student can be thrown 
 into the scrap basket of dead processes, and he will be able to 
 
154 MODERN DENTISTRY 
 
 devote the time thus saved to the study of pathology, bacteri- 
 ology, immunology, and surgery. With the new dentistry thus 
 instituted, it is possible that false teeth, crowns, bridges, fillings, 
 and pyorrhea instrumentation will be reduced in volume to i per 
 cent, of their present appalling proportions, and the future 
 medically trained dentists will be able to cope with the disease 
 of mouth infection, now almost universal, through efficient 
 instruction of the piiblic in the technic of scientific mouth hygiene. 
 Before the days of plastics, the making of a filling was a very 
 serious and exhaustive problem, yet many dentists, in spite of 
 the general improvement in materials, are still using the materials 
 and methods of the dark ages. Simple cavities in the grinding 
 
 surfaces of molars and bicuspids, cavities 
 in the sides of the teeth where there is 
 no force of mastication to be resisted, as 
 well as the compound cavities, are still 
 hammered full of gold, with useless 
 agony and fatigue to both dentist and 
 patient. But, fortunately, the great 
 majority of these cavities can now be 
 quickly and permanently filled with 
 Fig. 78.-Arrow represents siHcious cement. The filKngs that Can 
 point of cleavage. be safely made with silicious cement 
 
 are those that do not receive the force 
 of mastication, and those that do receive it, but are supported 
 on all sides by enamel walls; for silicious cement is insoluble, 
 strongly resists abrasion and withstands a high crushing strain. 
 When, however, a filHng is not supported on all sides, as in an 
 approximal contour cavity, such as we find in molars and bi- 
 cuspids, and receives the full force of strong mastication, the 
 cement is apt to crack off, its cleavage resistance being particu- 
 larly low. In such cases an inlay set in silicious cement should 
 be used (Fig. 78). 
 
 Porcelain Inlays. — Such an inlay may be of either porcelain 
 or gold. Where excessive force is to be withstood and the filling 
 is out of sight, the gold should be used with modern silicious 
 cement as a binder. But where the inlay is plainly visible, 
 
FILLINGS 155 
 
 porcelain may be used, as it can be matched to the tooth so as to 
 be really invisible, and it has sufficient strength to withstand 
 the force of mastication to an astonishing degree. Delicate, 
 frail porcelain tips cemented on the fractured corners of incisors 
 have already given good service for fifteen years and show every 
 sign of lasting indefinitely. It is true that any chance blow or 
 bite on a piece of bone or stone may dislodge them at any time, 
 but that may also be said of a corner of a natural tooth. The 
 wonder is not that a few insecure or frail inlays break away, 
 the great v/onder lies in the fact that so many of them last 
 indefinitely. 
 
 In displacing hammered gold for porcelain we are confronted 
 with the question: WiU porcelain withstand the force of masti- 
 cation, not better than gold, but sufficiently well to be worth 
 while? There is no question of comparing it with gold, for in 
 porcelain we have brittleness as an ob\dous danger, and therefore 
 in using porcelain as an inlay we must carefully consider its 
 relative strength and brittleness. 
 
 Porcelain Strength. — The principal forces that tend to dis- 
 lodge a porcelain tip are pressure, shear, and percussion. The 
 more the force is exerted longitudinally, that is, along the axis 
 of the tooth, and the nearer it is exerted to the cement base, the 
 less tendency there is for fracture. The more the force is exerted 
 transversely and the farther it is exerted from the base, the greater 
 the tendency for fracture. Of course, when force is applied 
 absolutely in the axis of the fiUing, the distance from the base, 
 theoretically, makes no difference, as there is no tensile strain 
 put on either side. 
 
 Dr. Jenkins' tests^ proved that pieces of porcelain i cm. 
 square by 2.3 mm. deep can stand a steady pressure of from 
 J ton for the Whiteley to i ton for the Jenkins porcelain, the others 
 falling somewhere within the intervening f ton. Dr. Jenkins 
 teUs us of the German laboratory in which these results were 
 obtained and how long it took to make them, but does not tell 
 us how they were made. I feel, however, that this great pressure 
 resistance could only have been obtained under the most perfect 
 ^Cosmos, May, 1902. 
 
156 
 
 MODERN DENTISTRY 
 
 conditions, where there was pure compression without percussion 
 or shear. However, if we could approximate these conditions in 
 the mouth, most of us would be satisfied with the Whiteley J-ton 
 resistance, as it is not likely that the human jaw would care to 
 tax itself more than that. 
 
 So much for steady compression. On this point, obviously 
 all porcelains are able to take care of themselves. We must. 
 
 Fig. 79. — Instrument for measuring shearing strength of porcelain. 
 
 then, look to shear and percussion for the weak points. First, 
 let us consider the effects of shear. For this purpose we have a 
 bar of porcelain, 0.075 ^y 0.125 inch, cemented into a block of 
 ivory and projecting perpendicularly from its surface. These 
 dimensions were chosen because they were felt to be safely above 
 the average size of any porcelain tip or corner, and yet to fairly 
 
FILLINGS 157 
 
 well approximate the conditions in the mouth. The porcelains, 
 unless otherwise stated, were fused on platinum and afterward 
 cut to the proper dimensions on a carborundum wheel. They 
 were identical, according to the Brown & Sharpe gage, within 
 o.ooi inch. Three separate instruments for measuring the shear 
 had to be made before friction, jam and variations in the pull 
 were successfully eliminated. Finally this simple apparatus 
 was devised (Fig. 79) : A represents a block of ivory with a smooth, 
 flat surface; B represents the porcelain bar, 0.075 by 0.125 
 inch cemented into the ivory block, A, at right angles to the 
 smooth surface; C represents a second block of ivory with a 
 smooth, flat face terminating in a knife edge. Block A was 
 screwed into a vise, so that its smooth face was absolutely 
 perpendicular. The smooth surfaces of A and C were placed 
 in apposition, with the knife-edge of C resting on the base of 
 the projecting porcelain, B. A bucket for weights was attached 
 in such a way as to bring the vertical line of force in the coinci- 
 dent planes of A and C exactly at the base of the porcelain bar. 
 Fine shot was slowly and steadily poured into the bucket until 
 the porcelain snapped. The shot, bucket, and block C were 
 weighed and the result noted. Block A was then removed from 
 the vise; the remaining bit of porcelain was crushed by a small 
 punch, reamed out with a drill, and another bar of porcelain 
 cemented into position. The procedure was then repeated. 
 
 The inlay porcelains tested in this way were Jenkins', 
 Brewster's, Whiteley's, and S. S. White's. 
 
 The Jenkins inlay material obtained in 1900 stood 23, 36, 
 27, 16, 33, 23, 23 pounds; average, 26 pounds. 
 
 The Jenkins improved inlay material stood 16, 14, 16, 15, 
 13 pounds; average, 15 pounds. 
 
 The Whiteley stood 28, 21, 19, 19, 18, 19 pounds; average, 
 21 pounds. 
 
 The Brewster stood 15, 20, 18, 23, 19 pounds; average, 19 
 pounds. 
 
 The S. S. White stood 29, 24, 25, 24, 25 pounds; average, 
 26 pounds. 
 
 Experiments were made on bars cut from blocks of molded 
 
158 MODERN DENTISTRY 
 
 porcelain made respectively of Whiteley and S. S. White inlay 
 materials, resulting in the following figures: S. S. White, 19 
 and 20 pounds; W^hiteley, 14 and 18 pounds. In these tests 
 the compressed porcelain shows less strength than the uncom- 
 pressed. It will be noted that the Jenkins improved material 
 had much less shearing strength than the older material, which 
 is probably due to the fact that Jenkins' improved material 
 made a better filling material although at a slight sacrifice of 
 shearing strength. 
 
 It was then determined to make pressure away from the base 
 of the bar so as to note the modifying effect of leverage. The 
 ivory block C was cut so that the knife-edge rested on the porce- 
 lain bar 0.075 iiich out from its base, and the attachment holding 
 the weight was adjusted to the new plane. Experiments showed 
 that porcelain standing 26 pounds, when applied at the base, 
 now broke at 6 pounds, demonstrating what a tremendous 
 difference is made by a very small leverage. Further tests were 
 made with the porcelain bar fastened into the base with a thin 
 packing of rubber-dam, and it was found that such a springy 
 base, not iinlike the peridental membrane around a tooth, made 
 no difference in the amount of direct pressure required to break 
 the bar. 
 
 To try the effect of a percussion blow the same apparatus 
 was adjusted horizontally, and instead of weights, rubber bands 
 were used to give the blow (Fig. 80) . The procedure was as fol- 
 lows: The ivory block holding the bar of porcelain was sunk 
 into an oak board to make a secure foundation. The plane 
 surface in which the porcelain bars were to be cemented was 
 parallel and true with the surface of the board. Nails at small 
 intervals were driven into the board for attachments for rubber 
 bands, which when attached to the 2-ounce ivory wedge would 
 snap it through a distance of | or | inch before it hit the porcelain 
 bar. The force of the rubber bands was so arranged as to draw the 
 ivory wedge perfectly true along the surface of the ivory before 
 it struck the base of the perpendicular porcelain bar. After the 
 porcelain broke, the pull of the rubber was measured by a spring 
 balance. The distance that the plunger was held from the porce- 
 
FILLINGS 
 
 159 
 
 lain was controlled by a small loop of twine fastened from the 
 head of the plunger to a nail driven into the wood at a suitable 
 place. It was found that perpendicular bars of porcelain hit by 
 the 2 -ounce plunger through a distance of | inch broke at a 
 ridiculously low figure. 
 
 With blows through j inch, a bar of Jenkins' old material, 
 cemented into the ivory surface, broke at 6, 8, 7, 5, 5, 5 ounces; 
 average, 6 ounces. 
 
 Jenkins' new material broke at 8, 9, 8, 9, 8 ounces; average, 
 
 8.4 ounces. 
 
 Whiteley's broke at 7, 8, 9, 10, 7, 6 ounces; average, 8 ounces. 
 Bars from Brewster body broke at 6, 5, 6, 5 ounces; average, 
 
 5.5 ounces. 
 
 Fig. 80. — Instrument for measuring the strength of porcelain under percussion. 
 
 Bars from an old S. S, White porcelain tooth broke at 5, 5, 
 6, 5 ounces; average, 5 ounces. 
 
 The S. S. White bars made from compressed porcelain broke 
 at 5, 6, 5, 6 ounces; average, 5.5 ounces. 
 
 The author does not care to make any general deductions 
 from these figures, but it is interesting to note that in general 
 the porcelain that stood the least shearing force had the greatest 
 percussion strength. Also that the compressed porcelain seemed 
 to have less percussion strength and less resistance to shear than 
 porcelain made without compression. AU of these bars of porce- 
 lain, when surrounded by rubber-dam instead of cement in the 
 ivory base, broke at 14 to 16 ounces, indicating that with per- 
 
l6o MODERN DENTISTRY 
 
 cussion blows the spring of the peridental membrane undoubtedly 
 greatly increases the force required to break porcelain. 
 
 Now as to the effect of percussion on the surface of a simple 
 porcelain inlay. The machine for testing was as follows : A j-inch 
 square filling of Jenkins' inlay material, o.i inch deep, was 
 cemented into a block of ivory. The sides were parallel and 
 perpendicular to the surface of the ivory. The block of ivory 
 was screwed into a board so that the side containing the filling 
 was perpendicular to the board. Then a brass plunger, headed 
 with a lower bicuspid tooth, was projected by means of rubber 
 bands against the filling through a distance of I and | inch 
 respectively. The strength of the pull of the rubber bands 
 was measured by scales fastened to the back of the plunger. 
 The results obtained were as follows: The edge was sKghtly 
 powdered at the first 5-ounce blow; at the third 5-ounce blow 
 a crack ran across the corner. This block of porcelain, the corner 
 of which was fractured by a 5-ounce blow, was thicker than the 
 block of porcelain of the same material claimed by Dr. Jenkins 
 to have stood a steady pressure of 2020 pounds. This corner 
 began to be powdered at the fourth lo-ounce blow. These 
 blows were all through a distance of I inch. The same blows 
 were given through | inch, and it was found that it took 7 ounces 
 to chip the edge. Another corner was tried, and it took i-pound 
 blows to break the corner, delivered through I inch. 
 
 The experiment was then tried of cutting a corner free from 
 the cement and ivory, leaving it supported beneath, about as a 
 corner of a tooth would be. The first 5-ounce blow chipped it 
 off a little and a 22-ounce blow was required to break it off 
 entirely. This test seemed to prove conclusively that porcelain 
 cannot withstand the full percussive force of the teeth. It 
 apparently can stand this force and more under steady pressure, 
 especially as this force is usually appHed through the inter- 
 vening medium of food, but we must accept the fact that no 
 porcelain has yet been made that can withstand the ordinary 
 percussive force that during mastication may at any time be 
 developed. Fillings, therefore, must be rounded so as to 
 receive glancing blows, the edges must be kept as free as pos- 
 
FILLINGS l6l 
 
 sible from strain, and if they chip, the powdered edge should 
 be cut out with a fine inverted cone bur and filled with silicious 
 cement. 
 
 The author has not gone into the subject of the specific gravity 
 of porcelains, for he has not been able to find that it has any par- 
 ticular bearing on the case. In fact, glass, which is porcelain 
 fused to even consistency, according to Hovenstadt's Jena glass 
 tests, seems to resist crushing force almost inversely propor- 
 tional to its specific gravity. It is interesting to note that all 
 the thirty-five glasses tested for crushing force stood from seven 
 to fourteen times as much as any of the porcelains tested by 
 Dr. Jenkins. It is also of interest to note that the bars of com- 
 pressed porcelain of S. S. White and Whitely inlay materials 
 did not stand as great a test as bars of the same material molded 
 in the ordinary way without pressure, seeming to show again 
 that great density is not necessarily a factor that makes for 
 strength in withstanding the force of mastication. 
 
 These facts seem to point to the following conclusions: AU 
 of the standard porcelains in the market are, for practical pur- 
 poses, equally strong, but none of them are strong enough to 
 receive the full force of mastication. So the question resolves 
 itself into which porcelain has the best colors and which is most 
 easily manipulated. 
 
 The Porcelain Inlay Matrix. — In 1887 Dr. C. H. Land made 
 mechanically perfect edges possible for intricate porcelain inlays 
 by devising the metal matrix. He made use of both gold and 
 platinum matrices, but found the latter preferable, as platinum 
 could be adapted with a facihty equal to gold, and allowed the 
 use of a high-fusing porcelain body that insured insolubihty 
 as well as giving the most life-like reproduction of the color of 
 the tooth to be repaired. From this discovery dates all effective 
 porcelain filling. Before this, pieces of porcelain had been ground 
 to fit labial cavities with fairly good results, and pieces of natural 
 enamel from extracted teeth had been inserted in a similar 
 manner, but the accurate adaptation of porcelain to approximal 
 or compound cavities was practically impossible until the metal 
 matrix was evolved. Some men still use a porcelain that can 
 
l62 
 
 MODERN DENTISTRY 
 
 be fused upon gold, but the higher-fusing porcelain requiring a 
 platinum matrix gives more consistent and better results. 
 
 Construction of a Porcelain Inlay. — The cavities should be 
 free from undercuts. If these are unavoidable through extensive 
 decay, the cavity should first be filled with phosphate of zinc, 
 then shaped into a perfect cup with a flat bottom. The edges 
 should be sharp and smooth, and where they are approximal 
 there must be suflicient separation to allow the metallic material 
 in which the porcelain is to be fused to be withdrawn without 
 distortion. The final polishing of the edges of the cavity can be 
 done with a small carborundum stone, which can be carved to 
 any shape and size with a diamond point. A finishing bur is also 
 excellent for this purpose, as is also a sand-paper engine disk. 
 
 Fig. 8i. — Cavities formerly filled with gold or porcelain- — now advantageously- 
 filled with silicious cement. 
 
 The silicious cements have so far replaced the insertion of 
 porcelain in simple labial or buccal cavities, as in Fig. 8i, that 
 there is not one inserted now where there used to be a hundred ; 
 and yet there are cases where the porcelain can be used with 
 advantage, for example, in the mouths of tobacco smokers, where 
 the cement would ordinarily discolor. Therefore the technic of 
 making such a porcelain filling can be advantageously included 
 in the general study of porcelain inlays. 
 
 Where the inlay is to stand the force of mastication the edges 
 of the cavity should be at right angles to the grinding surface 
 (Figs. 82 and 83). Such a precaution will obviously add to 
 the permanency of the filling, as it provides the greatest possible 
 resistance of both tooth and filling to the strain of mastication. 
 
FILLINGS 163 
 
 The preparation of the cavity being completed, the matrix is made 
 with rolled platinum, o.ooi inch in thickness. Foil thinner than 
 0.00 1 inch seems to lack sufficient body to stretch properly with- 
 out tearing. This platinum if annealed in a Bunsen burner or 
 with a blow-pipe will be harsh and unfit for use, but when 
 annealed in an electric furnace it becomes soft and tough. It is 
 most essential that the platinum be absolutely soft. The plati- 
 num is placed over the cavity and pressed with spunk or bibulous 
 paper as far as possible without tearing. This gives us the great- 
 est amount of metal with which to form a mold. The edges 
 now have become distinctly outlined, and from this time the 
 platinum must be held absolutely immovable or good results 
 cannot be obtained. When the edges have become outlined 
 
 Fig. 82. — Correct incisal angle for a Fig. 83. — Incorrect incisal angle for a 
 porcelain filling. porcelain filling. 
 
 they should be gone over carefully with ball burnishers (Fig. 
 84, d and b) and made sharp and free from wrinkles, the metal 
 being spun down into the cavity as far as can be done without 
 danger of tearing. Should wrinkles in the metal occur they must 
 be smoothed out before they reach the edge with the spatula 
 shown in Fig. 84, d. Then the metal should be boldly swaged 
 to the bottom of the cavity with bibulous paper held with the 
 pliers (Fig. 84, c). This can usually be accomplished without 
 tearing the foil, but if tears do occur they are quite harmless, 
 as they cannot extend to the edge where the foil has already 
 been adapted. Where the labial cavity extends under the gum 
 a larger piece of foil, held immovable well up on the gum and 
 swaged down on the cavity with bibulous paper, will form an 
 
164 
 
 MODERN DENTISTRY 
 
 arch that presses and holds the gum back, so that in cases that 
 at first seem absolutely hopeless of success the upper margin 
 of the cavity will be clearly defined. 
 
 The soft, unburnished platinum takes a beautiful in pres- 
 sion, but when the metal has been burnished or swaged it be- 
 
 a b c d 
 
 Fig. 84. — Instruments useful for forming a matrix. 
 
 comes elastic. If, therefore, the matrix be moved during its 
 formation an accurate impression is practically impossible, 
 for the elastic platinum when distorted, cannot be forced back 
 accurately into position until it has been re-annealed. The 
 matrix when finished should be carefully heated to redness in 
 order to render it sterile. In labial cavities the piece of platinum 
 
FILLINGS 165 
 
 should be cut sufficiently large to extend beyond the two ad- 
 jacent teeth, and the metal should be moulded to the three teeth 
 
 Fig. 85. — Position of instrument and fingers in burnishing a matrix into place on 
 upper incisors or canines. 
 
 by pressure with cotton and bibulous paper. The metal is then 
 held firmly upon the two adjacent teeth by the first and second 
 fingers, as in Fig. 85, when the general directions for adjusting 
 
 Fig. 86. — Position of fingers in forming a matrix to cavity in incisal corner of an 
 
 incisor. 
 
 the matrix to the cavity may be readily carried out. The large 
 piece of platinum has two great advantages — it conduces to 
 
i66 
 
 MODERN DENTISTRY 
 
 Fig. 87. — Position of hands in forming a matrix for a compound cavity on the 
 anterior approximal surface of a left upper molar. 
 
 Fig. 88. — Position of fingers in forming a matrix for the compound approximal 
 cavity in the posterior surface of an upper bicuspid or molar. 
 
 immobility of the metal during the formation of the matrix, 
 and it gives the entire labial form of the tooth, so that an accurate 
 idea may be obtained of the desired contour of the filling. 
 
FILLINGS 167 
 
 In corners of centrals, as in Fig. 86, the platinum should be 
 folded well over the labial and lingual surfaces of the teeth, then 
 it should also be bent over the cutting edge, forming a cap beneath 
 which shows the entire contour of the tooth, and by means of 
 which entire immobility may be obtained while the cavity margins 
 are being defined and the matrix formed. The same principle 
 applies in forming a half cap from a large piece of platinum for 
 
 Fig. 89. — Method of splitting platinum matrix near the impression of the 
 cavity in order to facilitate easy removal of the foil through a narrow space without 
 distortion. 
 
 the approximal cavities of bicuspids and molars. The platinum 
 should extend, as in Figs. 87 and 88, from grinding edges to 
 cervical margin, and along the adjacent sides of the tooth. This 
 can be firmly held with the index-finger and thumb of the left 
 hand, while the right hand with tweezers and bibulous paper 
 presses the metal partly into the cavity. The margins and floor 
 of the matrix may then be defined with a burnisher. It is most 
 
1 68 MODERN DENTISTRY 
 
 important that the greater part of the grinding surface of the 
 tooth shall be outKned in making the mold, as by this means 
 a truss effect is produced that will prevent the distortion of the 
 sides of the matrix, both when it is taken off the tooth and when 
 the porcelain is being fused. In mesial cavities the metal must 
 be pushed away from the operator and the matrix held by means 
 
 Fig. go. — An excellent device for holding metal immovable while being burnished 
 
 into position. 
 
 of the thumb and forefinger, as in Fig. 87. In distal cavities 
 the metal is pulled toward the operator, who works around and 
 beyond the fingers holding the platinum as in Fig. 88. When, as 
 sometimes occurs, the adapted platinum is dove-tailed around 
 the teeth so as to render its removal difficult or impossible without 
 distortion, the outer edge of the platinum may be split with a 
 sharp knife from the gum line to a point just beyond the cavity 
 
FILLINGS 169 
 
 margins, as is shown in Fig. 89. Figure 90 shows a method of 
 obtaining immobihty of the matrix by a clamp that is sometimes 
 useful. Figures 91 and 92 show the position of the fingers when 
 
 Fig. 91.— Position of fingers in holding the foil while matrix is being formed on 
 lower right side of jaw. 
 
 manipulating the matrix on the lower teeth. This, as before 
 stated, should be done while the matrix is held motionless in the 
 cavity. It is sometimes advisable, in order that perfect immo- 
 
 Fig. 92.— Position of fingers in holding foil while matrix is being spun into cavity 
 on lower left side of jaw. 
 
 bihty may be obtained during the final burnishing of the margins, 
 to re-anneal the matrix just before its completion, and then 
 after its replacement to pack it full of cotton or bibulous paper, 
 
170 MODERN DENTISTRY 
 
 leaving the edges exposed to the unrestricted action of the bur- 
 nisher. When this has been done and the packing removed there 
 will be no difficulty in teasing out an undistorted matrix from 
 the cavity. 
 
 Color Selection. — The color of the filHng must next be con- 
 sidered. This is one of the most important steps in the entire 
 operation, and while the accuracy of selection must ultimately 
 rest with the color sense of the operator, there are nevertheless 
 a few fundamental rules that will be of material assistance. 
 There are two great factors that must be solved if a porcelain 
 filling is to accurately match the tooth into which it is inserted: 
 first, the proper color must be decided upon by means of a sample 
 piece of porcelain on a shade ring; second, that porcelain must 
 be accurately reproduced by a judicious mixing of the basal 
 porcelain shades and by accurate baking. The question of de- 
 ciding on a color is not a mere question of matching the tooth, 
 but of deciding on the porcelain that will match the tooth per- 
 fectly after the porcelain is cemented into position. An inlay 
 may match a tooth perfectly before it is cemented into place, 
 and afterward be hopelessly off color, and the reverse is also true. 
 Many times the porcelain filHng that does not match at all out 
 of the mouth, when it is cemented into position will melt out 
 of sight and become invisible. In plain words, the shadow 
 cast by the cement that holds the inlay in position, or the shadow 
 cast by the tooth walls modifies the color of the inlay in an 
 astonishing degree. Therefore, in addition to the classification 
 — ^labial, buccal, approximal, contour, etc. — ^porcelain fillings 
 are to be considered in regard to their positions in the mouth, viz., 
 fillings that keep their color when cemented into place and those 
 that will be darkened by consequent shadow. The color of a 
 porcelain fiUing is dependent upon the perfection with which 
 the light is reflected to the eye of the observer. In a bright, 
 direct light yellow porcelain is yellow because all the other rays 
 that make up the light are absorbed and only the yellow are 
 reflected. If the light be gradually decreased, fewer yeUow rays 
 will be reflected and the color will become darker. When there 
 is no light the porcelain will appear black. Take, for instance, a 
 
FILLINGS 
 
 171 
 
 simple labial cavity, as illustrated in Fig. 93. If this extends 
 into the dentin sufficiently deep to prevent the color of the cement 
 from shining through it, and the porcelain is not overbaked, the 
 true color of the porcelain will be given. This is especially so 
 when the modern silicious cements are used for a binding. With 
 the old opaque phosphate cement it was always an approximate 
 match, "good if one didn't look at it too hard." In Fig. 94 the 
 fillings go straight through the labial and palatal walls of the 
 enamel, and yet, if both fillings are made of porcelain that matches 
 the tooth substance, the corner inlay when cemented into position 
 will look well, while the half-moon shaped filling will look dark. 
 If, however, the moon-shaped filling does not go through the 
 
 Fig. 93. — Porcelain inlay where color 
 of tooth is easily matched. 
 
 Fig. 94. — C, Easy to match; D, difficult 
 to match. 
 
 lingual waU and the cement extends entirely behind it, its color 
 will be nearly if not quite as good as that of the corner. The 
 difference of the shade of these two fillings may be explained as 
 follows: the corner C is illuminated by the side light from the cut- 
 ting edge, while the half -moon shaped filling D is shut in on four 
 sides, on three by cement and on the fourth by the adjacent 
 tooth. With D the light passes through the porcelain with a great 
 loss of reflection and with a loss of Kght, while with C the side 
 light brings out the color. It must be further noted, with refer- 
 ence to the corner C, that if it is looked at directly from in front 
 or from the direction of the arrow B toward the cement, the color 
 will be good. If, however, it is looked at away from the cement, 
 
172 MODERN DENTISTRY 
 
 as indicated by the arrow A, the color will be lighter or darker 
 according to the intensity of the Ught. This, however, is much 
 less apparent since the translucent siHcious cements have become 
 available. It should therefore be easy to obtain a good color in a 
 corner inlay. Buccal fillings in bicuspids and molars are as easily 
 matched as simple labial cavities, for they come under the same 
 condition of Hght reflection. Cervical fillings that extend to or 
 imder the gum are affected by the shadow of the gum, and all 
 approximal inlays from the posterior surface of the canines back 
 through the molars show the same falKng off in color, and unless 
 proper allowance is made for this, disheartening results will be 
 the outcome of otherwise careful work. There will be a darken- 
 ing of the inlay in direct proportion as the cement shuts off the 
 light and throws a shadow into the body of the porcelain, which 
 shadow can be overcome to a certain extent by the judicious 
 addition of yellow. 
 
 It will be found where a siHcious cement filling is used instead 
 of porcelain that the same law holds, and that a judicious modi- 
 fication in color must be made if a good match is to be obtained. 
 Those fillings not materially affected by shadow are simple labial 
 cavities, corners and tips of central and lateral incisors, and the 
 cusps of canines and bicuspids. Those most affected are posterior 
 cavities in canines, bicuspids, and molars. 
 
 There are a few principles that wiU be a guide in combating 
 this change of color. The shadow casts a blue into the filling, or, 
 at least, if that is not correct from the law of physics, blue added 
 to a filling will increase the shadow effect and yellow will counter- 
 act it. I shall give as an illustration an experience of my early 
 days in porcelain. I wished to insert an inlay in the posterior 
 surface of a canine, as in Fig. 95, that had a Hght yellowish-blue 
 color. I tried matching the tooth accurately and when the inlay 
 was cemented into place it looked like a piece of gray mud. It 
 was taken out, and after several trials I decided to make the 
 next inlay, if anything, too yeUow. So a fiUing of light chrome 
 yeUow was made and when cemented into place, it turned exactly 
 the color of the tooth, Hght yeUowish blue. So, in cavities 
 between teeth where the depth and cavity waUs wiU cause but 
 
96a 
 
 96b 
 
 97a 97b 
 
 Figs. 96a, 96b. — Porcelain inlays shown by the dotted line and the yellow 
 spot. These inlays have their respective colors when the light is thrown directly 
 upon them from a perpendicular axis, but when the light is thrown from the side, 
 as in Figs. 97a and 97b, the formerly perfectly matched filling of 96a appears 
 dark and the formerly yellow filling of 96b modified by the shadow of the cement 
 and cavity walls becomes a perfect match with the tooth color. 
 
FILLINGS 173 
 
 little shadow, the use of light yellow is a valuable aid in counter- 
 acting the color change; but when the inlay represents a bad 
 case of shadow to be overcome, deep yellow should be used and 
 marvelous matches will sometimes be achieved — matches that 
 seem like the work of necromancy (Fig. 96). For instance, we 
 here have two sound bicuspids with simple buccal cavities which 
 have been filled with porcelain inlays. The color of the teeth 
 in each instance is Hght yellowish gray, as is shown by the illus- 
 tration. The illuminating hght in this instance is supposed to 
 come from the front, where each filling will get direct Hght and 
 reflection. It will be noted that while the filling in ^ is a perfect 
 match, the filKng in -S is a decided yel- 
 low. This light reflection gives the fill- 
 ings their genuine color values. If, 
 however, the light comes in the direction 
 of the arrow and the cavity walls and 
 cement thus cast a shadow (Fig. 97), 
 it will be found that the supposedly 
 well-matched filHng in A becomes a 
 dark spot, while the filHng in B matches, Fig. 95. -Posterior por- 
 
 the yellow fading into Hght yellowish ^f 7ell^w ^Jll'countemTt 
 gray. With the tooth B the yeUow shadow. 
 will have to be added in sufficient 
 
 quantity. If there is not enough shadow the filling will still 
 be yellow; if there is too much shadow even the yellow fiUing 
 will be dark. 
 
 The same principle appHes in the mixing of cements, espec- 
 ially the siHcious cements. In matching the teeth the author 
 uses only three colors — dark yellow, hght yellow, and dark bluish 
 gray. There are, of course, a great variety of colors that could 
 be obtained, but they seldom just match and are usually a com- 
 promise: but with the three basal colors boldly used any effect 
 can be obtained, and the author strongly advises aU young 
 dentists to learn to mix their colors from the basal colors rather 
 than to depend upon the selections of the manufacturers. The 
 same principle appKes even more strongly in the mixing of the 
 various colors in porcelain work, for, as in the cements, the 
 
174 MODERN DENTISTRY 
 
 various manufacturers of porcelains make a large variety of mix- 
 tures, hoping to relieve the dentist of the artistic responsibility of 
 mixing his own colors. It is as though a professional house 
 painter depended upon the colors that were to be had in sample 
 cans, and never trained himself to actually mix the fundamental 
 colors himself. Such a painter, among his fellows, would be 
 considered a joke. 
 
 There is but one set of porcelains, to my knowledge, that 
 practically overcomes this ridiculous limitation. It is the porce- 
 lain made by Whiteley, with the shade rings (Fig. 98). This 
 set consists of seven fundamental colors, which, when variously 
 mixed, can make any shade in the shade ring. Not only are the 
 basal colors supplied, but also a table stating the approximate 
 proportions in which these colors should be mixed to form any 
 shade. The set also provides a box of powdered white silex, that, 
 when mixed with the porcelain in the proportion of i to 5, will 
 reduce the shrinkage so that a filling can be made in two bakings 
 rather than in six or seven, as is customary with other makes of 
 porcelain. The silex mixture can be used in the preHminary 
 bakings, but the final baking should be made with porcelain that 
 does not contain the silex, as the silex has a slightly lightening 
 effect, which, however, is not sufficiently marked to show through 
 and affect the color of the outside coating of porcelain. When 
 the various shades of porcelain have been selected they should 
 be mixed together on a clean glass slab and made into a paste 
 with water. The standard dryness is obtained by pressing a 
 muslin napkin or a piece of blotting-paper upon the mixture 
 until it has the consistence of dough. If the silex is to be used, 
 as is wise in the larger fiUings, this dough should be divided into 
 two portions and the silex thoroughly mixed with one portion, 
 in the ratio of i to 4 or 5 parts. 
 
 Making and Baking the Filling. — ^We are now ready to fill 
 the matrix with the porcelain dough. This should be done as 
 follows: The matrix should be seized with a pair of pHers at 
 such a portion of the platinum as will not distort or infringe on 
 the model of the cavity, and then a portion of the porcelain 
 dough should be placed within the matrix on the point of a brush 
 
Fig. 98. —A, Seven fundamenlal colors which, judiciously selected and mixed, can 
 reproduce any color on the circular shade ring below, B. 
 
FILLINGS 
 
 17: 
 
 or spatula (Fig. 99) and settled into position with a rub of the 
 rough handle on the pliers that hold the platinum. This rubbing 
 of the rough handle on the pliers jostles the porcelain particles 
 closer together and makes them float in the water of the dough, 
 so that with skilful manipulation the porcelain can be placed in 
 any shape or position desired. More 
 porcelain paste can be added at will 
 until it comes up to the edges, which 
 should be kept scrupulously clean. The 
 making of the contour is most important 
 and is one of the great tests of the skill 
 and artistic sense of the porcelain worker. 
 After the filled matrix has been care- 
 fully dried, by keeping it face downward 
 on a piece of soft muslin, it is placed 
 at the door of an electric furnace, care- 
 fully dried until all steam stops rising 
 from it, and then it is placed in the 
 oven and baked until a gloss appears. 
 It is advisable to support the filled 
 matrix on a piece of platinum to pre- 
 vent its possible adherence to the floor 
 of the furnace. 
 
 The baking will cause the porcelain 
 to shrink about one-fifth of its bulk. 
 The partly filled matrix must then be 
 removed, allowed to cool, filled once 
 more up to the edges with porcelain, 
 and baked again. A third or fourth 
 baking may be used as needed. After 
 the baking is completed, the filling may 
 be taken from the furnace almost im- 
 mediately, as practically only very large pieces need to be 
 cooled slowly, although, theoretically, a gradual cooHng will 
 make the porcelain tougher. The platinum should now be 
 stripped off, care being taken to pull it away from the edge. 
 Should it be pulled toward the edge, chipping is likely to occur. 
 
 Fig. 99. — Brush and 
 instrument for handling 
 and molding porcelain 
 paste. 
 
176 MODERN DENTISTRY 
 
 If small portions of platinum stick to the porcelain they can 
 be pulled off with a sharp-pointed, tempered instrument or a 
 small, sharp engine bur. 
 
 In large or difficult cavities a double burnishing is sometimes 
 advisable. The procedure is as follows: The first addition of 
 the porcelain to the matrix is not allowed to come to the edge. 
 This is baked and cooled. The matrix is put again accurately 
 into the cavity, held immovable, and the edges reburnished. 
 
 Inserting the Inlay. — Before cementing the inlay into place, 
 grooves should be made in the porcelain by using a thin copper 
 or steel disk charged with diamond-dust or carborundum powder 
 (Fig. 100). The diamond-dust is incorporated in the metal by a 
 mechanical process, but the carborundum is used as a paste, 
 made with glycerin or cane syrup, in which the disk is immersed 
 
 Fig. 100. — Disk charged with diamond-dust. 
 
 before the cutting of the porcelain is attempted. The diamond 
 disk is more easily manipulated, but it is also very expensive and 
 wears out quickly, while the loose carborundum and revolving 
 metal disk is sharp and permanently effective for all but the 
 smallest fillings. It is well not to mar the edges of the fUHngs 
 with the grooves, but this is not now as great an injury as formerly, 
 when only phosphate of zinc cement was available. If there is a 
 sHght imperfection in the margins, well-selected silicious cement 
 will fill it so as to make it quite invisible. The disk and porcelain 
 must be kept thoroughly wet while the grooves are being cut, 
 and the grooves should be as deep as the size of the filhng will 
 permit, so as to allow the cement to enter and act as a dowel for 
 the attachment of the inlay to the tooth. The mere adhesion of 
 the cement is an uncertain quantity and should not be depended 
 upon to retain the filling in position. For instance, in Fig. loi, 
 
FILLINGS 
 
 177 
 
 A represents the filling in position ; B the tooth in which we find 
 the cavity. Such a filling cemented into place with rough sides 
 would be only moderately secure, but if the inlay and tooth 
 cavity were grooved so that the grooves would be opposite 
 each other, as in Fig. 102, the cement would act as a pin, holding 
 the inlay in position in the tooth, and it would only be dislodged 
 by the actual breaking of the cement. Thus, it is evident that 
 greater stability is obtained by large grooves than by the adhesion 
 
 Fig. loi. — Incorrect and insecure method of securing an inlay in position, 
 inlay here depends upon the adhesion of cement alone. 
 
 The 
 
 obtained by merely roughening the inlay and cavity walls. In 
 fact, the nearer we can approximate the shape of a collar-button 
 in shaping the inlay for retention, the greater will be the stability 
 obtained. While the grooves are being cut the inlay should be 
 held so that the edge adjacent to the intended groove may be 
 buried in the skin of the finger. The groove can then be fearlessly 
 made by the swiftly revolving metal disk, that cuts only the hard 
 porcelain and pushes back the yielding tissue of the finger without 
 
 Fig. 102. — Dowel principle of holding an inlay in position with cement. 
 
 inflicting injury. With large inlays, where there is plenty of room 
 for the grooves, carborundum disks are most useful. If the 
 porcelain is blackened by the disk the discoloration may be 
 readily removed by a strong jet of water thrown upon it. 
 
 The method of inserting the inlay is as follows: The fiJHng 
 and cavity should be washed in alcohol and dried, and the cavity 
 protected by a napkin or rubber-dam. Silicious cement of the 
 proper color should be mixed to the consistency of soft dough 
 
178 MODERN DENTISTRY 
 
 and placed in the cavity, and the inlay picked up with the sticky 
 spatula, placed in position, and settled home by a tapping motion 
 that will rapidly bring the inlay into position. When it is in po- 
 sition the setting of the cement can be hastened by flowing hot 
 paraffin upon it. This setting wiU be accomplished in a minute 
 or two so that the patient can be dismissed. Wherever it is 
 possible it is well to leave an excess of cement to be polished off 
 at a later visit, as, theoretically, the more thoroughly the cement 
 is protected from the action of the saliva during setting, the more 
 perfect the results. On the following day the edges may be ground 
 with an Arkansas stone or poHshed with sand-paper. It is better 
 for finishing that the edges of the filling should be a little below 
 the edges of the cavity rather than too high. If, however, the 
 porcelain is too high, it can be ground down and still give good 
 results, but the original gloss, in most cases, is to be preferred. 
 
 Cautions. — Having described the general operation of making 
 and putting in a porcelain filKng, a few cautions may not be out 
 of place. Overf using is one of the great causes of poor colors, 
 that is to say, the porcelain should never lose its amorphous 
 consistency. In very deep cavities a bar of porcelain extending 
 through the bottom of the matrix makes a valuable anchorage 
 to which the rest of the porcelain can be advantageously added. 
 In large contours excessive contraction should be overcome by 
 adding i part in 4 of ground silex to the part of the porcelain 
 that is to be used for the first baking, as the unfused particles 
 of silex extend across the matrix in every direction, making what 
 is practically an internal investment. When handling small 
 fillings the pHers and cavity may be advantageously kept wet 
 up to the time of insertion, to prevent the filHng from being 
 dropped and lost. To place a tiny filling on the operating case 
 in the same relative position that it will take in the tooth pre- 
 vents mistakes as to which side should go in first. 
 
 There are three classes of furnaces that can be used for fusing 
 porcelains — gas, gasoline, and electric. The gas and gasoline 
 furnaces are noisy, odorous, and dirty, and are seldom used where 
 electricity is available. On the other hand, the electric furnace 
 is clean, silent, and beautiful. The best electric furnace for 
 
FILLINGS 
 
 179 
 
 porcelain, in the author's opinion, is the Hammond crown furnace 
 (Fig. 103). It is so constructed that if a muffle burns out it can 
 be at once replaced by a new one, and the work continued with 
 a loss of not more than fifteen minutes. The various gages 
 for telling when the porcelain is fused are a needless expense. 
 The porcelain worker should learn to fuse porcelain by experience 
 and his eye, not by mechanical appliances, since no mechanical 
 appliance will be able to accurately diflferentiate the relative 
 time required to fuse a small filling, a crown or a bridge. Such 
 
 Fig. 103. — Hammond electric furnace. 
 
 appliances tend to dwarf the natural ability of the porcelain 
 worker and through their complexity cause a great waste of 
 valuable time. 
 
 The gold inlay has practically perfect edge strength, and 
 therefore, on account of this advantage is sometimes to be pre- 
 ferred to the porcelain inlay. This is especially the case when 
 the filling involves a large contour and is to be subjected to a 
 great stress of mastication. It also has the great advantage 
 over porcelain of being capable of serving as an abutment for a 
 
l8o MODERN DENTISTRY 
 
 cantilever bridge, but this will be gone into more particularly 
 in the chapter on bridge work. 
 
 The gold inlay is easily made and its construction ought not 
 to take over ten or fifteen minutes. This is mentioned because 
 the casting methods and various intricate processes recommended 
 tend to make it a long, tedious, uncertain procedure. These 
 may take hours if not days, to do, with uncertain results, that 
 which a simple method can accompKsh in a few minutes. For 
 instance, a simple gold inlay in the buccal surface of a molar 
 ought not to take over five minutes, at most, to complete after 
 the cavity is prepared along the lines previously stated, that is, 
 cup shaped, with sloping sides and a flat bottom, as in Fig. 104. 
 
 Fig. 104. — Simple cavity prepared for gold inlay: A represents external view; 
 B represents cross-section. 
 
 Soft gold plate, bout 0.003 inch in thickness, should be 
 held immovable over the cavity with the fingers and burnished 
 and swaged into position, forming the matrix. Extra immobility 
 can be obtained by molding the gold to the grinding surface of 
 the molar. Then moss fiber or sponge gold should be firmly 
 packed into the gold matrix up to the edges of the cavity, with 
 large pluggers. If the matrix gets wet during the process no 
 harm results. The edges, however, should be kept free from 
 the moss fiber or sponge gold. The filled matrix should then be 
 removed and 22-karat solder flowed into it by adding a few 
 grains of borax and squares of solder and holding it over a Bunsen 
 burner with a pair of pHers. No investment is necessary. The 
 filling should then be cut out of the gold plate, leaving a small 
 margin at the edges. This margin is later polished off when the 
 
FILLINGS 
 
 l8l 
 
 filling is cemented into place. The filling and cavity can then 
 be undercut, as previously described, and the filling cemented 
 into place. As before stated, a simple cavity hke the one just 
 described would not now be filled with gold, but with silicious 
 cement. The process has been described to show the simplicity 
 
 Fig. 105. — A, Lower bicuspid; B, lower molar; C, gold inlay to be constructed. 
 
 of the moss fiber gold matrix method in comparison with the 
 more complicated, intricate casting methods. The place most 
 suitable for a gold inlay is in the compound approximal cavity 
 of a bicuspid or a molar, and as the method of making such a filling 
 is so important, it will be given in detail. 
 
 Fig. 1 06.- — Occlusal view of Fig. 105. 
 
 Let us take, for example, an inlay for a large cavity in the 
 anterior surface of a first lower molar, such as is shown in Figs. 
 105 and 106. In Fig. 105, A represents the bicuspid against which 
 the contour of the filling is to be made. B represents the molar 
 
l82 
 
 MODERN DENTISTRY 
 
 with the cavity to be filled, and C the shape of the completed 
 inlay in position. Figure io6 represents the occlusal aspect of 
 the same cavity. In Fig. 107 the solid lines of D and E show side 
 and three-quarter views of completed inlay. This is the type of 
 inlay to be used where the pulp is alive, but where the pulp has 
 been removed and the chamber can be utilized for purposes 
 
 Fig. 107. — Solid lines show shape of inlay for Figs. 105, 106. Dotted lines 
 show projection that may be added when the loss of pulp gives sufficient space, 
 as in Fig. 108. 
 
 of retention, the inlay can be constructed according to Fig. 108, 
 which is self-explanatory. The only point of interest is the pro- 
 jecting notch of the inlay that extends into the pulp chamber, 
 which is further demonstrated by the dotted lines in Fig. 107. 
 The cavity being prepared as shown in Fig. 108, with sloping 
 sides and sufficient space between it and the bicuspid to prevent 
 
 Fig. 108. — Similar to Fig. io6, except that there is an extra depression in the floor, 
 permitting greater possibilities of retention for the inlay. 
 
 distortion of the matrix on its removal, soft gold 0.003 inch in 
 thickness should be sHpped in between the bicuspid and the 
 molar so that it will project well beyond the lower margin of the 
 cavity that hes next to the gum. Then wet bibulous paper should 
 be packed in between the teeth, forcing the metal well into the 
 
FILLINGS 183 
 
 hollow of the cavity. This should be done before the gold foil is 
 bent to the contour of the outside of the tooth. The matrix 
 should then be removed, the gold thoroughly annealed again, 
 when it should be replaced in the cavity and packed firmly with 
 bibulous paper a second time. Then the gold plate should be 
 folded over the side of the tooth and conformed to the top of 
 the tooth so that it assumes the shape of a half-cap. The bibulous 
 paper should then be removed and the gold burnished and spun 
 into all parts of the cavity with a ball burnisher. There will be no 
 difl&culty in holding the gold immovable with the thumb and 
 forefinger of the left hand while this is being accomplished. 
 When the matrix is completed a mass of sponge gold should be 
 molded somewhat into the shape of a wedge, having approxi- 
 mately the amount of gold necessary to make the filling. It 
 should be shghtly warmed over the Bunsen burner to make it 
 adhesive, and then placed within the matrix while the matrix is in 
 the cavity. Care should be taken to allow some of the sponge gold 
 to rest and infringe upon the grinding surface of the adjacent 
 bicuspid, against the side of which the contour of the inlay must 
 rest. When this has been done the sponge gold must be firmly 
 and rapidly condensed into place with large broad pluggers, care 
 being taken to condense it thoroughly against the contact point 
 of the bicuspid wall and to overlap it partly on the grinding 
 surface of the bicuspid. More gold can be added if necessary, and 
 in a short while a large gold filKng can be molded into the proper 
 bite and position. The gold foil and filled inlay can be teased 
 out without destroying the shape of the inlay and the whole 
 filling filled with 22-karat solder, as previously described, by 
 soldering it over a Bunsen burner. If the gold has been well con- 
 densed against the adjacent wall of the bicuspid, and the solder 
 is not placed upon the exact contact point, the entire inlay can 
 be filled solidly with solder and then be slipped directly back into 
 position, giving a perfect contact with the bicuspid and making 
 an inlay that can be trimmed and polished in a few minutes. 
 It is advisable to always place the solder on the grinding surface, 
 as this surface will generally need to be ground in any case in 
 order to obtain perfect articulation. 
 
184 MODERN DENTISTRY 
 
 The great advantage of this method lies in the fact that it is 
 so easy to learn, and has such innumerable possibilities in the 
 ease of construction of half crowns, three-quarter crowns, com- 
 plete crowns with facings, and cantilever bridges; but all of these 
 will be discussed under their respective headings. I was once 
 showing a graduate class the method of making the filling, just 
 described, on a model. After I had shown them once or twice 
 how to make the inlay (it never took over five minutes) one of 
 the students said, "That is all very well with a skilful man, but 
 how about the average dentist?" I answered, "Give me one 
 of your average students." One of the students came for- 
 ward, and I said to him, "Now, do just as I say, and don't 
 think how you can improve my method before you learn it." 
 And so, under instruction, he also made an inlay in less than 
 five minutes. This is spoken of to show that the method is easy 
 of accompHshment if one wiU take the trouble to seriously 
 attempt it. 
 
 Before closing the subject of gold inlays it might be said that 
 small tears at the bottom of the matrix are of little consequence, 
 as the gold will fiU them completely, and it is advisable in filling 
 the matrix with gold not to let the gold extend over the matrix 
 margins. If the edges are kept clean, the filling will be more 
 quickly finished and inserted. It should be especially remembered 
 in undercutting the filling that the grooves should come as nearly 
 as possible opposite the grooves in the tooth cavity, so that the 
 inlay will be keyed into place with good, strong, rigid cement 
 dowels. 
 
 Plastic Fillings. — The cement question has been so much 
 discussed in connection with inlays that it might be of value to 
 discuss briefly the relative merits of the phosphate of zinc cements 
 and the silicious cements. 
 
 Phosphate of zinc cement is valuable inasmuch as it appears 
 to be more adhesive than sihcious cement. It is therefore useful in 
 cementing on attachments to the teeth, such as bands for ortho- 
 dontia appliances, crowns and bridges. Its adhesive, tenacious 
 quahty makes it most valuable as a seal for the retention of 
 antiseptic dressings, but on account of its solubility it has pal- 
 
FILLINGS 185 
 
 pably had its day as a filling designed to permanently restore 
 a spot of decay. Of the phosphate of zinc cements, the Harvard 
 cement and the new S. S. White slow-setting cement are the 
 easiest to work and, on account of being more slow in setting, 
 give the best results. 
 
 The silicious cements, as before stated, are capable of being 
 mixed to absolutely match the tooth structure to be replaced; 
 they are quickly inserted and are insoluble. Without doubt 
 they represent the greatest single advance the mechanics of 
 dentistry has ever known. The author has had excellent results 
 with both the Ames sihcious cement and the synthetic cement. 
 Where the cement powder is coarse, as is the case with the syn- 
 thetic cement, a very thin cement Kne can be obtained by cement- 
 ing the inlay into place with the cement mixed to the consistency 
 of soft dough, and then placing dry powder on the excess that 
 has exuded from the margins of the cavity. When this is done 
 the heavier granules are compressed within the cavity and the 
 more liquid portions are squeezed out, and the addition of the 
 dry powder insures a perfect cement bond on the edge. There 
 are times, however, when a crown or inlay must largely depend 
 upon the adhesion of the cement for its retention, and under 
 these conditions a combination of phosphate of zinc and silicious 
 cements may be advantageously used as a retaining bond. The 
 method is as follows: When the cavity is prepared and dried, 
 the silicious cement should be mixed ready for use. The creamy 
 Harvard cement should then be rapidly prepared and inserted 
 as a cavity Hning, and the silicious cement immediately placed on 
 the inlay or crown and pushed into position, forcing out all excess 
 phosphate cement. 
 
 Amalgam.— Before the cements reached their present strength 
 and beauty amalgam was sometimes used as a bond for retaining 
 inlays in place. In respect to strength and insolubility it was 
 most trustworthy, but its color tended to cause a shadow in the 
 inlay, that it was almost impossible to counteract, and the dark 
 edge was most unsightly. However, since we are dealing with 
 the possible bonds for inlays it might seem advisable to go into 
 
1 86 MODERN DENTISTRY 
 
 the methods necessary for the insertion of amalgam, either as a 
 cement or as a filling material. 
 
 Let us first examine the philosophy of inserting the amalgam 
 filling. It must set hard, be free from excess mercury, and must 
 have a bacteria-tight margin. A bacteria-tight margin, not a 
 water-tight margin, for a water-tight margin around a non- 
 adhesive filling in a moisture-soaked tooth is as much of an im- 
 possibihty as such a margin would be in a wet sponge. There- 
 fore, what one desires to obtain is a bacteria-tight filling, and 
 with amalgam it makes no difference whether the cavity is wet 
 or dry if only it be kept free from bacteria. On general principles 
 it is better to have a dry cavity than a wet one, but the main 
 thing with the insertion of amalgam is clean, firm, aseptic edges. 
 Then if a cavity whose edges extend under the gums is flooded 
 with alcohol or some other appropriate antiseptic, and this anti- 
 septic is immediately pushed out by the doughy amalgam, which 
 amalgam is dried of its excess mercury by wafered amalgam or, 
 better stUl, sponge gold, the final results will be just as effective 
 as though the gums had been jammed away from the root by 
 rubber-dam or a matrix and the cavity dried with hot air prior to 
 the insertion of the filUng. Since amalgam is not in the least 
 adhesive the cavity must be well undercut in order that there may 
 be good dowel retention. The old method of mixing amalgam 
 powder with a pestle and mortar is quite obsolete. The best 
 method, in the author's opinion, is to put the desired amount of 
 mercury and alloy in a small-sized test-tube. The finger or 
 thumb should then be placed firmly over the end and the con- 
 tents shaken vigorously for a minute, at the end of which time 
 the resulting mixture should be emptied into the hand, where it 
 can be easily kneaded with a few rubs of the thumb, and the 
 material will be ready for insertion. The formulae recommended 
 by Black and Flagg for amalgam have given continued satis- 
 faction in the author's practice. The wafering is accomplished 
 by taking some of the excess soft amalgam and squeezing it in a 
 muslin napkin with a pair of pliers until all excess mercury is 
 forced out. The resulting wafer is then added to the soft amalgam 
 filling by means of a spatula moderately heated. The mercury 
 
FILLINGS 187 
 
 in the filling will be sucked out into the substance of the wafer, 
 which will become correspondingly soft. The softened wafer 
 can then be shaved off and another wafer used, or the excess 
 mercury in the first wafer can be squeezed out and the wafer 
 appHed again and again, until there appears to be no excess mer- 
 cury in the filling. After this it is well to tamp the filhng into 
 the cavity with a large plugger to be sure that all the space 
 formerly occupied by the extracted mercury has been fully 
 replaced by the denser amalgam. This should be accomplished 
 by a tapping motion not unlike the motion used for setting 
 porcelain paste. Amalgam in its pasty condition, before it sets, 
 is similar in consistency to a mixture of sand and water, so if 
 it is merely pushed into position the larger particles will jamb 
 on each other and large unfilled spaces will result. But if, Hke 
 the porcelain paste, the fiUing is tapped and jostled, the large 
 particles will float in the Hquid mercury and come in closer 
 approximation, while the mercury will rise to the surface, as the 
 water rises to the surface of the porcelain dough when it is simi- 
 larly jarred for the purpose of condensation. When the last 
 tamping has been accompHshed, and enough of the wafer added 
 to ensure perfect contours and edges, sponge gold, slightly 
 warmed to drive off any free moisture, should be pressed upon 
 the surface of the fiUing until it sticks. The patient is then dis- 
 missed. If the gold adheres until he returns it can be polished 
 off; if it does not adhere, it means that there was no excess mer- 
 cury. In either case the result is a dense filling inserted quickly 
 and painlessly. It is a source of wonder that many dentists stiU 
 work amalgam in the dry state, when equal if not better results 
 are obtained by using it as a plastic. 
 
 The author is aware that the use of a piece of sponge gold 
 that costs from twenty-five cents to a dollar., for the hardening 
 of an amalgam filHng, will seem a monstrous extravagance to 
 many dentists who would rather work half an hour or even an 
 hour longer to avoid such "wilful waste," even though they are 
 working over a sensitive, suffering patient. 
 
 Amalgam as a Cement.— When an anchorage for a bridge is 
 to be made in an amalgam filling, the pin or gold inlay should 
 
1 88 MODERN DENTISTRY 
 
 be inserted into the mushy amalgam that has been placed in 
 the cavity. The pin or inlay should then be tapped into position 
 until it settles to its proper level, care being taken that vents 
 have been made on the edges of the inlay sufficiently large to 
 allow the amalgam grains to flow, out or to permit of tamping 
 with a plugger after the appHcation of amalgam wafers or sponge 
 gold has drawn out the excess mercury. Amalgam has also been 
 successfully used to attach facings that have broken away from 
 bicuspid and molar bridges. The technic is as follows: The 
 porcelain is thoroughly undercut with a carborundum or diamond 
 disk, the gold is undercut with fissure and wheel burs, and the 
 soft mushy amalgam is pressed on the porcelain facing, and the 
 facing is pressed into place. The excess amalgam is allowed to 
 squeeze out around the sides, and a piece of sponge gold is plas- 
 
 Fig. 109. Fig. no. Fig. in. Fig. 112. 
 
 Figs. 109-112.— Steps in the sponge-gold process of restoring a broken-down root 
 
 with amalgam so that it may readily be crowned. 
 
 tared over the outside of the amalgam and the facing, and held 
 there until the excess mercury is absorbed. The patient can then 
 be sent away with the gold in position, care being taken to see 
 that it will not interfere with the bite. When the patient returns 
 on the following day the gold can be polished off and the amal- 
 gam joint will be found hard and firm. This method is especially 
 valuable in replacing facings for bicuspids and molars where 
 teeth with all-porcelain grinding surfaces are used. 
 ^ Repair of Broken Roots. — By using the sponge-gold method 
 of extracting the mercury from soft amalgam, roots fractured 
 beneath the gum can be quickly and easily restored so as to 
 form effective abutments for bridges; or in back teeth they can 
 be readily and easily built up to a complete masticating contour. 
 The method is as follows: Figure 109 represents a cross-section 
 
FILLINGS 
 
 189 
 
 of a broken bicuspid root that has been fractured beneath the 
 gum margin, A. The irregular Hnes represent the cavity pre- 
 pared inside for the retention of the amalgam that is to restore 
 the gum margin and make the root a suitable, wholesome abut- 
 ment for a crown or bridge. Amalgam should be prepared as 
 previously described, then the head of the root and gum should 
 be wiped off with 4 per cent, formalin or pure carbolic acid, 
 and the soft amalgam inserted into the cavity of the root and 
 tamped well into all interstices. Wafering, as described, should 
 be done until the amalgam has a stiff, doughy consistency. There 
 should be a final tamping and the amalgam should be smoothed 
 and shaped as in Fig. 110— B representing the sponge gold andC 
 the amalgam. Then the sponge gold should be pressed down 
 firmly with the thumb, when it will result in a condition as shown 
 
 Fig. 113. 
 Figs. 113-117.- 
 
 Fig. 114. Fig. 115. Fig. 116. Fig. 117. 
 
 -Same principles can be applied to the restoration of a crown of a 
 tooth. 
 
 in Fig. III. D represents the excess amalgam that extends 
 beyond the edge of the root, and must be rem.oved later. The 
 patient may then be sent away, and on the following day the 
 restored root head can be carved with fissure burs and filed to 
 resemble Fig. 112, when a band crown can be made so as not 
 in any way to infringe on the gum. 
 
 If a complete amalgam restoration of the crown is desired, 
 as is sometimes the case in back teeth, the following method can 
 be used: Figure 113 represents a molar tooth broken on one side 
 beneath the gum line, as shown by E. Figure 114 represents a 
 partial restoration made after the manner of Figs. 109-112. 
 This should be made and finished absolutely free from masti- 
 cating contact with the occluding tooth before the occlusal sur- 
 face is formed. Then the amalgam and tooth should be cut to 
 
IQO MODERN DENTISTRY 
 
 form a cup (Fig. 115) to receive the second installment of 
 amalgam that should be inserted in a soft condition and tamped 
 into position. The amalgam should be roughly molded to the 
 shape desired and the occluding tooth bitten into it so as to 
 form a perfect occlusion (Fig. 116), It should be carved to shape 
 so that the swing of the jaws will not disturb it, and it must be 
 sufficiently plastic to be molded without breaking. WTien it is 
 of the proper shape the teeth should be closed and warmed 
 sponge gold pressed firmly on the side, as is shown in Fig. 117. 
 The patient should wait some five mi nutes with the Jaws still. 
 After that he may be sent away with the gold still adherent; 
 if it loosens, it is of Kttle consequence. He should be warned 
 not to bite on the tooth until the following day, when the filling 
 can be trimmed and carved as desired. The necessity for making 
 the filling in two sections arises from the fact that unless the 
 amalgam is supported during the process of cry-^tallization it is 
 easily broken, and therefore it is wise to make the first part 
 entirely free from any possibility of being reached by the occlusal 
 stress of the opposing tooth until it has become absolutely hard. 
 After this has been accomplished the final occlusal surface can 
 be quickly and safely added. 
 
 The method of making an amalgam filling with a perfect 
 contour against the adjacent tooth, as is shown in Fig. 118, is easy 
 and simple. A represents the sound tooth and B the tooth 
 with the cavit}' to be filled. Care should be taken to prepare 
 the ca\-ity so that there will be good strong margins at the 
 cervical border, and also that there will be ample separation 
 between the decayed tooth and the one against which the con- 
 toiur is to be made. The dotted lines represent the diagrammatic 
 outline of the ca\dty within the tooth. After the ca\-ity is pre- 
 pared with suitable undercuts, and dried or flooded with an 
 antiseptic, as may be most feasible, soft amalgam is pressed 
 into the ca\'it3' and tamped into all the recesses. K there is an 
 occlusion with the opposing tooth, the teeth should be shut 
 upon the amalgam and the filli ng carved to the desired shape 
 with a fine lancet or any suitable plastic instrument. It wiU 
 then resemble the filling C in Fig. 118. Then sponge gold can 
 
FILLINGS 
 
 191 
 
 be pressed upon it, or it can be hardened by wafering, so that all 
 excess mercury is extracted until the filling becomes about as 
 hard as chalk. If the edges of the tooth project slightly above 
 the filling after this has been done, some of the excess amalgam 
 of the filling can be wafered, rolled, and ironed into position 
 with a hot ball burnisher. The patient should be sent away, 
 with instructions not to bite upon the fiUing for twenty-four 
 hours. When the patient returns, the filling can be poHshed 
 with fissure burs, sharp lancets, or scrapers, and, finally, by sand- 
 paper disks, but care must be taken not to polish or cut away 
 the actual point of contact between the filling and the adjacent 
 
 Fig. 118.— Method of building an amalgam con- Fig. 119.— Method of build- 
 
 tour filling against an adjacent tooth. ing two contour amalgam fill- 
 
 ings against each other without 
 aid of matrix. 
 
 tooth. Ordinarily the filling can be carved and poKshed without 
 separation, by careful carving up to the contact point, for the 
 contact point is polished by being forced against the polished 
 enamel of the adjacent tooth. Finally, all rough or sharp edges 
 can be eliminated by passing a fine band-saw between the filling 
 and the tooth, which will push them apart and reduce all edges, 
 so that floss-silk will jam sharply as it is passed over the contact 
 point, but will otherwise have free passage for its daily duty of 
 cleansing the interdental space. 
 
 If two cavities oppose each other, as in Fig. 119, one may be 
 built up to the proper contour, as previously described, and 
 
192 MODERN DENTISTRY 
 
 polished at some future sitting, when the second can be inserted, 
 or they can both be filled at once as a common filling. The 
 wafer or sponge gold should be used until the amalgam has be- 
 come chalk-Kke, then the two fillings can be carved to have a 
 common contact point. A fine steel band-saw should be passed 
 through the contact point A and the fillings entirely separated. 
 Then the mouth should be rinsed with water. After this the 
 two fillings should be ironed into absolute contact at the contact 
 point with a hot ball burnisher. They will not join, as the water 
 will act as a bar against their union. After this the patient can 
 be dismissed, and the fillings polished and finished at the next 
 sitting. 
 
 Gutta-percha has been used as a bond for inlays, crowns, and 
 bridges, and therefore, in order to finish the discussion of various 
 cements and also the various filling materials, gutta-percha will 
 next be considered. When used as a cement for an inlay, a little 
 hard gutta-percha should be placed in the dried undercuts of the 
 cavity and spread with a hot instrument evenly over the entire 
 surface as a lining. Then it should be wet, and the inlay, with- 
 out undercuts, should be pressed upon it with a hot instrument 
 until the gutta-percha flows out of the margins to a considerable 
 extent. Then the inlay should be removed and the excess gutta- 
 percha should be ironed off by the sharp edge of a hot plastic 
 instrument, care being taken to always iron it toward the edge. 
 The inlay should be inserted a second time and the process re- 
 peated until the inlay is almost in position. Then it should be 
 removed and the undercuts made. The surface of the gutta- 
 percha should be dried and the inlay inserted and sent horne with 
 a hot instrument, all excess gutta-percha being removed with 
 a sharp knife and a pellet of cotton soaked in a gutta-percha 
 solvent, such as oil of cajuput, oil of eucalyptus, or chloroform. 
 
 This use of gutta-percha, however, in the light of our present 
 cements is obsolete, and it is now seldom used except for- temporary 
 attachments or for crowns or bridges where there is a possibihty 
 that they may need to be removed in case of re-infection due to 
 lack of cleanHness or to low bacterial resistance. When a crown 
 is to be set in gutta-percha the cavity in the root should be 
 
FILLINGS 193 
 
 beveled and kept moist so that the gutta-percha can be easily- 
 removed during the process of fitting. The base of the crown 
 and the pin, if it has one, are then undercut and thoroughly- 
 dried. They are then slightly moistened -with oil of cajeput or 
 eucalyptus and -white base-plateg utta-percha placed on the pin 
 or within the band. The crown is heated and pressed into posi- 
 tion as far as possible on the root, which should be wet. When 
 the gutta-percha is cold the crown should be removed, which is 
 easily accomphshed, and the excess gutta-percha trimmed off 
 and the process repeated until the crown goes absolutely into 
 position. Then it is removed, the gutta-percha dried, the root 
 dried, shghtly roughened and moistened with oil of cajeput, 
 and the crown heated and pressed into position. It should be 
 held firmly in place for a minute or two and then the patient 
 dismissed, being told not to bite upon it for an hour or two. 
 After that time it will be firm, but at any time heat from a hot 
 instrument appHed to the outside will make its removal easy. 
 The same principle applies to the insertion of bridges with gutta- 
 percha, although, as a matter of fact, the author has not used this 
 method of retention oftener than once or twice a year during 
 the past ten years of practice. 
 
 Gutta-percha is a most valuable filhng for cavities wHere 
 decay is progressing rapidly and it is difficult to determine just 
 how much can be saved and just how much should be cut away. 
 If the tooth is soaked in carbolic acid or formalin and filled with 
 gutta-percha, at the end of about a month a permanent filhng 
 can be inserted with much greater chance of success than if the 
 temporary gutta-percha had not been used. The fact that the 
 temporary filhng gives us an opportunity for repeated steriliza- 
 tion is, of course, a great advantage. In addition to its permit- 
 ting of resterilization, gutta-percha is particularly valuable as a 
 packing in between teeth where the teeth are too close together 
 and inflamed gum has worked into the cavity. In such cases 
 if the gutta-percha is inserted after a moderate excavation the 
 force of mastication will cause it to spread the teeth and force 
 the gum out of the cavity, so that ample room can be obtained 
 for a good interdental space. This separation ordinarily takes 
 13 
 
194 MODERN DENTISTRY 
 
 about three months after the filling has been inserted and causes 
 no pain. 
 
 Gutta-percha has a wonderful property of becoming very 
 hard and adhesive. It would seem that a sort of vulcanizing 
 takes place, making a filling that at times seems not unlike 
 cement. The great disadvantage about gutta-percha lies in the 
 fact that in time it will disintegrate and discolor. This process 
 is very slow, but nevertheless steady, and therefore the other 
 filling materials under ordinary circumstances are to be preferred 
 where durability is to be desired. 
 
CHAPTER VIII 
 
 CHILDREN'S TEETH 
 
 The Theory of Gum Lancing m Infants. Care of the Teeth and 
 Gums After the Eruption of the Temporary Second Molars. 
 
 Gum Lancing. — "Teething is a natural process and assistance 
 by lancing is unnecessary." This is the stock objection raised 
 by the opponents of this time-honored procedure, but it should 
 be remembered that the same objection would hold with the 
 same force against assisting nature with forceps during parturi- 
 tion. Many physicians maintain that retarded dentition is 
 seldom, if ever, a cause of the bowel complaints and the general 
 nervous condition and malnutrition that are so common among 
 children during their first and second summers. It is claimed 
 that lancing forms scar-tissue in the gums that retards the erup- 
 tion of the teeth. And it is also claimed that many a child suffer- 
 ing from coHc, scurvy, and a hundred and one of the ordinary 
 infantile ailments has been uselessly lacerated with a lancet, and 
 the little sufferer's pain, far from being stiUed, was actually 
 increased. 
 
 There is no doubt a child suffering with incipient measles, 
 smaU-pox, scarlet fever, or even a misplaced pin would not be 
 benefited by having its gums lanced, but when the child during 
 its dentition period suffers from malnutrition, bowel disorders, 
 restlessness and fretfulness, or shrieks without apparent cause, 
 it is a rash physician who would be absolutely sure that dentition 
 is not one of the underlying causes of these distressing symptoms, 
 even though the gums may appear perfectly normal. It should 
 be remembered that the pain of teething does not arise from the 
 pressure of the tooth upon the gum, but that the pressure of the 
 gum upon the tooth causes the pain by creating pressure upon 
 the underlying nerve. A single retarded wisdom tooth in an 
 
 195 
 
196 MODERN DENTISTRY 
 
 adult may cause such pain and nervous shock that the bowels 
 will be violently disturbed and there will be high fever, all of 
 which symptoms will disappear when the entire grinding surface 
 of the offending molar is freed from its overhanging tooth capsule. 
 The pressure of the tooth capsule on the posterior cusp alone 
 may cause these symptoms, all the other cusps being free. 
 
 The same condition has been noted in children of six or 
 twelve years during the eruption of the sixth- and twelfth-year 
 molars. The restraint of the posterior cusp alone by a tough 
 gum may in these cases cause profound nervous excitability with 
 its concomitant physical disturbances. These disturbances are 
 easily diagnosed because the patient is intelligent enough to 
 explain. Therefore, in the case of a screaming, coKcky, feverish 
 infant who cannot explain, and who possibly has not only one 
 but eight teeth pressing on the dental pulps, how unfair it is to 
 the child to ignore the fact that difficult dentition may be the 
 underl3dng cause of all the trouble. 
 
 Since we know that one single cusp of an unerupted sixth- 
 year molar often causes distressing systemic symptoms that can 
 be instantly removed by lancing, the failure frequently encoun- 
 tered by physicians in obtaining relief after lancing is no doubt 
 often due to imperfect technic in lancing. Unless the dental 
 capsule covering the cusps of an erupting tooth is dissected 
 absolutely clear of it, so as to reheve all back pressure on the 
 nerve by the gum, lancing may cause no reHef whatever. With 
 wisdom teeth covered by a large mass of gum it is sometimes nec- 
 essary after the gum has been dissected to burn the capsule 
 away with trichloracetic acid. When this is done, even though 
 the gum still overlies the tooth, rehef is at once obtained. Many 
 physicians fail to appreciate that the only value in lancing Hes 
 in completely dissecting the tooth free from the dental capsule. 
 The complete lancing of incisors and canines of teething infants, 
 to the expert, presents few difficulties, as the lancet can readily 
 be passed all around the cutting edge of the tooth beneath the 
 gum, but in the case of a deep-seated molar the overlying block 
 of gum must be completely removed and the capsule absolutely 
 cleared if the physician is to be assured that that particular 
 
children's teeth 
 
 197 
 
 tooth may not continue to be a cause of reflex systemic disturb- 
 ance. And where, as is often the case, four molars may be under 
 suspicion at the same time, and the teeth are far under the gum, 
 it is a nice question to decide how much surgery is justified. It 
 has been the author's experience that lancing of even four molars 
 at a time not only causes no shock to the child but results in 
 almost immediate rehef. However, the full history of the child 
 must be taken into consideration, and all infantile disturbances 
 should not be attributed in bulk to faulty dentition. 
 
 The question of scar-tissue formed by lancing has not been 
 seriously discussed, as ordinarily the tooth erupts long before 
 scar- tissue sufficiently dense to interfere can be formed; and if 
 scar-tissue does form the great rehef obtained by judicious 
 lancing more than compensates for the possible necessity of a 
 second or even a third lancing. 
 
 Care of Children's Teeth and Gums. — Unless the child has 
 been very badly nourished during gestation, or within the first 
 few years of childhood suffers either from malnutrition or some 
 disease such as measles or scarlet fever, the first and even the 
 second teeth, the wisdom teeth excepted, are likely to erupt 
 sound and normal. The formation period of the enamel of all but 
 the wisdom teeth Hes within these few years, and if the enamel 
 is well formed prior to its emergence from the gum, the tooth 
 will have every opportunity for perfect development as the roots 
 and dentin go on forming after it is erupted. But with the enamel 
 this is not so, for when the tooth emerges from the gum the enamel 
 organ dies and no more enamel can be formed. The formed 
 enamel can harden or soften according to its nature, as shown 
 in Chapter III, but with the emergence of the tooth from the gum 
 growth in the enamel ceases forever. The enamel first forms 
 at the tips of the cusps or cutting surfaces of the teeth, as in 
 Fig. 120, the formed enamel being shown by the shaded portion, 
 and it frequently happens that the permanent molars erupt 
 before the pits or fissures in the grinding surfaces are completely 
 closed, thus destroying the enamel organ before its work is com- 
 pleted. Sometimes although the bottom of the pits or fissures 
 are covered with sohd enamel, the fissure itself is partly filled 
 
198 MODERN DENTISTRY 
 
 with a soft material that acts as a special lodgment for infection. 
 Therefore, the first thing a dentist should do when a child is 
 brought to him is to carefully examine all the pits and fissures 
 with a fine, sharp piano-wire explorer. The wire is not hard 
 enough to penetrate into normal enamel, and so, when jammed 
 into each suspected place, if it sticks on being withdrawn, the 
 dentist can be assured that there is a soft spot which should be 
 poHshed out with a stone or bur until the explorer no longer 
 sticks. Normal mastication of food will keep the bottom polished 
 and will absolutely prevent decay. The fissure must be made 
 self-cleansing, and if the enamel is penetrated entirely the softened 
 structure must be entirely removed and a cement fiUing inserted. 
 This procedure will not weary the child and will enable the tooth 
 to safely mature, when it can be filled in a more permanent man- 
 ner. In any case it is not a bad procedure to flow a thin layer of 
 
 Fig. 120. — Showing diagrammatically formation of enamel at upper surface of the 
 dental capsule, the white portion being yet soft and gelatinous. 
 
 phosphate of zinc cement into the grooves after the polishing 
 is completed. This makes the tooth smooth to the action of 
 the tongue and gives an excellent opportunity for the cut enamel 
 to gradually harden as the cement dissolves. I speak of the 
 enamel hardening, for the results of my experiments, as given 
 in Chapter III, indicate that enamel is harder on the surface 
 than underneath, and when it is cut the exposed surface becomes 
 hard also — a sort of case-hardening process that renders it 
 resistant to attrition and yet not Hable to fracture. At least, 
 whatever the explanation may be, the above-mentioned pro- 
 cedure gives excellent results, and when the cement is worn or 
 washed away by the saliva the tooth performs its functions 
 satisfactorily without further filling. 
 
children's teeth 
 
 199 
 
 If this has been done carefully as soon as the teeth erupted 
 and the teeth are not deformed, and if floss-silk and tooth-brush 
 are used as described in Chapter II, the teeth and gums should 
 
 I 
 
 II 
 
 I 
 
 u 
 
 ! 
 
 J 
 
 Fig. 121. — Carborundum stones used for polishing grooves and softened enamel 
 
 in children's teeth. 
 
 always be free from decay and infection. But, as a matter of fact. 
 the floss-silk and tooth-brush will seldom be used as recommended. 
 Parents should not only tell the children to brush the teeth and 
 to use floss-silk, but should see that the children do it properly. 
 
200 MODERN DENTISTRY 
 
 Otherwise the bacteria will collect against the enamel and remain 
 undisturbed indefinitely, and finally cavities of decay will appear 
 in the temporary teeth. When the spots of decay are small and 
 have not infected the pulps they can be made comparatively 
 harmless, since they can be cut out and filled with amalgam, 
 gutta-percha, or cement. Then if the parents take heed, and 
 see that the teeth are properly cleansed with floss-silk and tooth- 
 brush, the child may grow to maturity and have a perfectly 
 healthy set of teeth. But if a pulp in a temporary tooth becomes 
 infected so that the pulp has to be removed, we are face to face 
 with one of the most serious and difficult problems in dentistry. 
 And the worst part of the whole miserable dilemma lies in the 
 fact that it is so easily preventable by proper cleansing. Any 
 mother who brushes a child's teeth properly and uses floss-silk 
 carefully three minutes a day is giving the child years of health 
 and vigorous maturity. The only proviso is that she must do it, 
 or see that it is done, every day, not every other day or once a 
 week. Nor does it assist matters when decay has penetrated 
 to the pulp to hear her exclaim, "Well, I told him to brush his 
 teeth!" To think that the poor dentist has to listen to such 
 drivel day in and day out! Tell a child of seven, eight, or ten 
 to brush his teeth! A child of eight or ten does not wish to 
 brush his teeth, does not know how, and won't do it even if he is 
 taught, unless he is coaxed and made to do it ; and yet it is ordi- 
 narily during these years that the enamel becomes permanently 
 infected and the foundation for firmly intrenched mouth in- 
 fection is laid. The fundamental cause of mouth infection is, 
 first, ignorance on the part of the parents, and after that laziness 
 or overwork; for it is quite conceivable that a mother of six 
 young children may readily prefer to send the children to the 
 dentist twice a year, and put the responsibility on him, than to 
 go through with the great ordeal of seeing that over one hundred 
 teeth are carefully flossed and brushed each day. And yet if 
 she really knew the good she would do them and the money 
 she would save, I am sure the ordinary mother would gladly 
 see that her children's teeth were kept clean. 
 
 However, let us suppose the evil is done, and the child is 
 
children's teeth 20I 
 
 brought to us, when seven or eight years old, with cavities in the 
 temporary teeth that have extended until the pulp is exposed, 
 and well-defined spots of decay have started in the sixth-year 
 molars and the central incisors. The child's gums are usually 
 inflamed and the teeth coated with white masses of bacterial 
 deposits. The first essential is to gain the confidence of the 
 child. It is well to merely cleanse the child's teeth at the first 
 visit, and show him how to use the tooth-brush. The tooth- 
 brush should be small and of the size and design shown in Fig. 9, 
 and, above all, should be dipped in hot water and allowed to 
 cool prior to its first use on the sensitive gums. This will prevent 
 too great irritation and will not discourage the child from coming 
 again. The movements to be used in brushing the teeth are 
 given in Chapter II. The child should also be taught to use 
 floss-silk, as previously stated, in order that the bacterial masses 
 may be removed from between the teeth once at least, if not 
 twice, daily. The silk should be held in the manner described 
 in Chapter II. This is most important. The taut part should 
 be pressed down between the tooth surfaces of each interdental 
 space, sweeping one side going in, traversing firmly across the 
 gum, and then sweeping the side of the adjacent tooth going out. 
 This is not a simple operation; it requires instruction and patience 
 if it is to be mastered, and nothing but careful training on the 
 part of the dentist and parents will make the child have either 
 the knowledge or the will to do it properly. The next thing is 
 to remove the green stain that is usually found on the teeth by 
 first flowing a little tincture of iodin on them and then polishing 
 with brush and pumice. Never, if it can possibly be avoided, 
 should a child be hurt on his first visit, and at no time should a 
 child be taxed beyond the easy Kmit of his endurance. Of course, 
 if a child comes to a dentist with an abscessed tooth, the open- 
 ing of it may hurt, but no more pain should be inflicted than is 
 absolutely necessary to give relief. On the second visit a small 
 cavity of decay may be fiUed. This should be accomplished 
 by carefully yet rapidly cutting out the decay with a swift 
 sweep of a rapidly revolving sharp bur. It should never take over 
 a few seconds to accompHsh this, and if the child is permitted 
 
202 MODERN DENTISTRY 
 
 to hold the napkin around the tooth with his fingers while the 
 work is being done, it is astonishing how readily and even cheer- 
 fully he will bear the necessary pain. The mere fact that the 
 child is assisting by holding the napkin distracts his attention. 
 It is astonishing how quickly a child responds to the S3rmpathy 
 of the dentist who really loves children and desires to assist them. 
 Those who are not capable of feeling this sympathy laugh and 
 scoff at such a claim, but it has been my experience that children 
 treated lovingly and honestly, skilfully and quickly, are the best 
 patients a dentist can have, and when their confidence is gained 
 they will bear with fortitude pain that would make an older 
 person wince. The main essentials in dealing with children is 
 never to deceive them, never to overtax their power of resistance, 
 and never to fail to let them see that you care for them person- 
 ally, but with it all to make them feel that they must obey. 
 If a thing has to be done, persuade and coax the child if neces- 
 sary, but see that it is done before he leaves the chair. And it 
 will be a great proof of a dentist's discretion to plan for any one 
 visit an efficient course of procedure that will not overtax the 
 child's power of endurance. 
 
 When the cavity of decay in a temporary tooth has been 
 excavated, the tooth should be filled so that it will last four or 
 five years, or until it comes out to make room for its successor. 
 In such a case the putting on of rubber-dam or jamming the gum 
 with clamps is folly. The amalgam, cement, or gutta-percha 
 should be prepared for use according to the material to be used, 
 and then the napkin should be applied and the child told to 
 hold it in position. Then the cavity should be quickly wiped 
 out with a pellet of cotton moistened with carbolic acid or nitrate 
 of silver, and the filHng at once inserted. If amalgam is used 
 the antiseptic will do good, and if the cement or gutta-percha 
 are deemed desirable the small amount of moisture due to the 
 antiseptic film will be only a theoretic objection, especially 
 if the cavity contains judicious undercuts. The same procedure 
 applies to filling the permanent teeth of a child. Gutta-percha 
 and cements can certainly tide the child over the formative 
 period of the dental roots and pulps, and then operations of 
 
CHILDREN S TEETH 203 
 
 greater length, if necessary, can be performed. It will be noted 
 that this gentleness and firmness applies to mature patients 
 as well as children, but it is especially essential in the control of 
 children. A doctor who is not a thorough humanitarian has no 
 right to call himself a doctor. A doctor was once talking to a 
 bright woman about the doctor's Hfe, and after the late hours, 
 loss of sleep, and constant worry had been gone over, the woman 
 said, "Well, medicine is certainly a very poor business." "Quite 
 true, madam," was the response, "but it is a very fine profession." 
 And so the dentist who perpetrates mechanical operations of 
 unnecessarily tedious length is not a surgeon, but a mechanic, 
 and should confine his efforts to the workbench, not to the 
 sensitive human tissues. 
 
 Exposed Pulp in Temporary Teeth.— When the dentist 
 finds a temporary tooth, usually one of the molars, with a cavity 
 that has involved the pulp he is confronted with a problem that 
 will tax his ability to its utmost. It is difiicult to treat and fill 
 the canals of a permanent molar, but with the temporary molar 
 the canals not only have to be treated and filled, but they have 
 to be filled with a root filhng that will absorb as the roots 
 absorb, when the permanent tooth beneath begins to emerge 
 to take its place. If the pulp is alive it should be anesthetized 
 by means of the novocain pressure method, as described in 
 Chapter VI, and should then be thoroughly removed from the 
 canals by Beutelrock drills and the piano-wire broaches. Then 
 Buckley's mixture of formafin and tricresol should be sealed in 
 with cement and the Httle patient dismissed. It is wise to wait 
 a fuU month in order to be sure that the irritation of the root 
 tips has entirely subsided. When the patient returns the napkin 
 or cotton roll can be applied either with the clamp or held by 
 the child, and the filling and dressing removed by a swiftly 
 revolving drill. The same treatment should again be repeated, 
 and within a week the root canals should be permanently filled 
 in the following manner: The filhng and dressing should be 
 removed as before, hot air should be appHed, and the canals 
 quickly dried. Then a paste of oil of cloves and oxid of zinc 
 should be flowed and Hghtly tamped into the canals. Any excess 
 
204 MODERN DENTISTRY 
 
 oil of cloves should be absorbed by a suitable amount of oxid 
 of zinc added to the pulp chamber. All excess can be wiped or 
 scraped from the pulp chamber, and the tooth can be filled 
 with any suitable material, such as amalgam, cement, or gutta- 
 percha. Of course, chloro-percha and gutta-percha can be used 
 in the root canal, but the oil of cloves seems to give the best results 
 and has the property of being absorbed with the rest of the root 
 as the permanent tooth underneath erupts. The best way, 
 however, is to prevent the decay of the tooth before it starts 
 by seeing that its entire surface is kept clean with floss-silk and 
 the tooth-brush. 
 
 Fractured Teeth. — One of the most distressing accidents 
 that can happen to children's teeth is the fracture of a newly 
 erupted permanent tooth that exposes the pulp long before it 
 has completed its task of forming the tip of the root. It is almost 
 invariably one or both of the upper central incisors that is frac- 
 tured. Sometimes the fracture is almost enough to expose the 
 pulp, but not quite. The pink of the pulp vessels may be just 
 visible through the fractured surface, and yet the pulp may not 
 be exposed. Under such conditions the fractured surface should 
 be wiped off with pure carbolic acid, thoroughly dried, and a film 
 of thin cement flowed over it and allowed to harden. This may 
 protect the pulp so that it will continue its life for three or four 
 years or until the root is fully formed, when the tooth can be 
 restored to its normal color and contour by a skilfully appHed 
 porcelain filling. In the meantime, if desired, the tooth may be 
 temporarily restored with cement. But when the pulp is exposed 
 so that its death is imperative, it is wise to apply novocain and 
 remove the pulp at once. When this has been accomplished 
 and the soft parts have been thoroughly removed, it is frequently 
 found that the entire tooth is composed of little more than enamel 
 and cementum, the dentin being almost entirely missing. The 
 pulp chamber instead of being minute, as it would have been if 
 the tooth had matured, is a large canal with its diameter varying 
 from 0.125 iiich at the fractured edge to 0.0625 inch at the root tip. 
 And what is of more serious consequence, the tip of the root is 
 so imperfectly developed and so full of organic material that in 
 
children's teeth 205 
 
 the course of time it is sure to be partly absorbed, and therefore 
 if it is thoroughly filled to the end, such absorption will leave 
 a projecting root-canal filling. On the other hand, if the foramen 
 is not filled to the end the force of mastication will drive the 
 sharp edges of the partly formed apical foramen into the tissues, 
 making an irritation that is almost certain to cause an infection 
 which will result in a chronic alveolar abscess. Under such con- 
 ditions the tooth and root should be carefully studied with the 
 a;-ray, a hard tube being used for the differentiation of the hard 
 calcic portions of the tooth and a soft tube being used to bring 
 out the soft tissues, as represented by inflammatory or alveolar 
 degeneration. This will be of incalculable value in determining 
 the depth of the root-canal filHng. 
 The pulp chamber should be thor- 
 oughly sterilized with applications 
 of pure carbohc acid, followed by a 
 4 per cent, aqueous formaldehyd 
 solution, which should be sealed in 
 with phosphate cement. If an ab- 
 scess has formed at the tip it is ad- 
 visable to squeeze into it a drop 
 or two of pure carbolic acid by . ^'^- 12 2. -Diagrammatic 
 
 -,„ , 1 r 11 11 1 illustration of a child's broken 
 
 filhng the canal full and then mak- ^^^^^^^ ^^-^^^ ^^^-^^ ^^^ ^d- 
 ing pressure on the external open- jacent teeth. 
 ing with a ball of soft, unvulcanized 
 
 rubber. After this has been accomplished a cotton dressing 
 should be inserted and the tooth sealed up with cement for about 
 a week. When the child returns, careful measurements of the 
 root outline should be made on the a--ray plate, and these should 
 be compared with similar measurements made on the tooth, 
 so that the exact size and length of the pulp canal from the broken 
 edge to the apical foramen can be ascertained. Then the upper 
 part of the canal should be filled with a plug of gutta-percha, 
 care being taken that it accurately fits the apical foramen. 
 This is a very nice procedure, as is shown by the illustration 
 (Fig. 122). A represents the broken tooth; B and C, the normal 
 adjacent teeth. The dotted lines show the outline of the pulp 
 
2o6 MODERN DENTISTRY 
 
 chamber and apical foramen. D represents the area of softened 
 inflamed tissue at the end of root. E represents the uncalcified 
 portions of the normal tips of the adjacent teeth. The black 
 area, F, represents the position the gutta-percha should take. 
 If a small short cone of gutta-percha is thrust into the canal 
 on the end of a probe it will go completely through the tip into 
 the tissues, making an added source of irritation, and if a large 
 bulky piece of gutta-percha is jammed into the canal the chances 
 are that it will not reach the foramen at all. The only practical 
 way out of such a dilemma is to see that the root canal is abso- 
 lutely conical to the tip. This can be accomplished by a suitable 
 reamer. Then, while the canal is allowed to remain wet with 
 a 2 per cent, formaldehyd solution, a piece of gutta-percha is 
 molded into a cone approximately the correct size, heated 
 slightly, and pushed with a large probe as far into the canal as it 
 will go. It should then be allowed to cool. Then it should be 
 withdrawn on the end of the probe, sHghtly heated again, and 
 pushed in again and once more allowed to cool. So long as the 
 canal is wet the removal of the cone will be easy. This should 
 be tried again and again until the measurements show that 
 the solid cone of gutta-percha has passed the end of the conical 
 root canal and has sealed it perfectly. Then the cone should be 
 once more withdrav^n, a scratch having been first made on the 
 probe opposite th. 'oken edge of the tooth. Then a careful 
 measurement of the exact distance of the foramen from the broken 
 edge of the tooth should be made with another probe having a 
 hooked tip. The depth should be compared with that of the 
 x-xdiy plate and the exact distance should be marked off on the 
 gutta-percha from the scratch on the probe and the excess gutta- 
 percha cut off. When that has been done the cone on the probe 
 should be allowed to cool and the root canal thoroughly dried 
 with hot air and moistened with oil of eucalyptus on a shred of 
 cotton. Then the gutta-percha cone and the probe should be 
 inserted into the tooth firmly up to the mark on the probe, which 
 ought to bring the gutta-percha exactly to the end of the root 
 canal. The gutta-percha probe can then be left in position for 
 a minute or two in order that the oil of eucalyptus may make a 
 
CHILDREN S TEETH 207 
 
 firm union between the gutta-percha and the tooth. Then a hot 
 instrument should be placed against the probe within the tooth 
 cavity. This will heat the metal so that it can readily be with- 
 drawn, leaving the gutta-percha cone in position. After the 
 probe has been withdrawn the hole in the gutta-percha can 
 be filled up by tamping the gutta-percha into position with a hot 
 instrument, leaving the tip of the root evenly sealed. On the 
 following day another oj-ray can be taken, and if the gutta-percha 
 is not absolutely in position it can be pushed a little further with 
 hot instruments, for it is better that it should extend from the 
 orifice very slightly than to allow the undeveloped foramen to be 
 unfilled. The tooth can then be bleached as described in Chap- 
 ter VI, and a porcelain tip made to restore the tooth to its normal 
 length. 
 
 The ideal surgical treatment of the tip, of course, would be to 
 go through the alveolar process with a bone drill and amputate the 
 end of the root, leaving the gutta-percha smooth and even; 
 but at the age of seven, eight, or nine the mouth is too full of the 
 underl)dng permanent teeth, and the jaw-bone is too small in 
 its development to safely attempt such a procedure. It is better 
 to coax such a broken tooth along, soothing any inflammatory 
 outbreaks with iodin and other quieting treatment until the 
 jaw is more fully developed. Then at the age of fourteen, if the 
 tip is not in a healthy condition, root ampu " jn with novocain 
 can be undertaken with every possibility of permanent good 
 results. 
 
 ORTHODONTIA FOR THE GENERAL PRACTITIONER OF DEN- 
 TISTRY 
 
 The straightening of children's teeth has undergone a great 
 revolution during the last twenty years, and has developed 
 from a haphazard, hit-or-miss procedure, that frequently resulted 
 in more harm than good, into a precise science that produces 
 permanent results. And strange to say, the originator of the 
 fundamental principles underlying the modern method was a 
 Frenchman who lived some two hundred years ago — Pierre 
 Fauchard, the father of professionaHsm in dentistry. He scorned 
 
2o8 MODERN DENTISTRY 
 
 that human suffering should be made a field for selfish commercial 
 exploitation, and therefore freely told of his discoveries to all 
 who would listen, when each fellow-worker was guarding his 
 secret as personal property. Among Pierre Fauchard's many 
 discoveries was the expansion arch which is now generally 
 accepted as the best means of straightening crooked teeth. His 
 plan was to attach to the teeth an arch of spring wire of the 
 shape that the human arch ought to assume, and then, by liga- 
 tures, to draw the teeth into position and hold them there, letting 
 the arch act also as a retention appliance. But, like most great 
 ideas, his plan was too simple and direct to be understood or 
 accepted. After his death the expansion arch was neglected 
 and forgotten. Later, practitioners in straightening one tooth 
 frequently made another crooked with appliances of great 
 complexity and size. These appliances frequently injured the 
 gums and teeth permanently because it was impossible to keep 
 them clean. Moreover, the later dentists almost invariably 
 started to straighten by casually extracting a few, which made 
 facial distortions and malocclusions that were ten times worse 
 than if the patient had never seen a dentist. 
 
 But about twenty years ago Angle, of St. Louis, Baker, of 
 Boston, and Case, of Chicago, all awoke to the advantages of the 
 expansion arch, and it was shortly afterward that the Angle 
 School of Orthodontia was started. Angle made appliances 
 that were of almost universal application, and he classified the 
 various procedures, by which crooked teeth could be straightened 
 with quickness and precision. A conscientious old dentist of 
 the old school once said at a dental meeting that he had been 
 paid thousands of dollars for straightening children's teeth, and 
 he regretted to say that the teeth had never remained straight, 
 and that untold harm had resulted from the regulating appliances, 
 and therefore the money paid had been more than wasted. 
 Naturally, he was opposed to straightening teeth. And in the 
 light of the work he had done this old gentleman was quite 
 correct. But the work started by Fauchard and carried on by 
 Angle was a work that converted chaos into order, hideousness 
 and disease into beauty and health. The principles laid down by 
 
CHILDREN S TEETH 209 
 
 Angle and his co-workers were that the teeth were created by 
 a better intelligence than theirs, and if there were thirty-two 
 permanent teeth it was better to utilize all of them and learn 
 their design and proper relation than to extract some teeth and 
 then plan what should be done with the rest. Angle formulated 
 the theory that the teeth did not grow to fit the face, but the 
 face grew to fit the teeth. It was discovered that if the teeth 
 could be made to assume their true, normal arch the rest of the 
 face would develop to corresponding symmetry and beauty. 
 Also that the arch of the teeth was the keystone on which the de- 
 velopment of the upper bones of the face and forehead depended. 
 If the arch was constricted, the openings in the nose were les- 
 sened or even closed, preventing proper breathing. The passage 
 of the air through the nose being cut off, air pressure was not 
 exerted in the various sinuses of the face, and therefore this 
 important stimulant to facial development was weakened or 
 entirely missing. And so the new school of orthodontia started 
 out with the endeavor to understand nature's plan and to co- 
 operate with it. 
 
 Thirty years ago it was the invariable rule never to start to 
 straighten teeth until the permanent canines had fully erupted. 
 Now, in the light of Angle's work, every dentist knows or ought 
 to know that when the canines have emerged from the gum it is 
 almost too late to do effective work. At least it will take four 
 or five times the amount of work and consequent pain and suffer- 
 ing, to accomplish a harmonious result, that it would have taken 
 if the teeth had been placed in their true positions before the 
 canines erupted. This is so because the canines are now known 
 to lock the arches into their permanent positions. Formerly, 
 the dentist pulled and yanked the teeth hither and yon in a vain 
 hope that with the help of Providence and a little luck they 
 would come straight. The aim of even the most advanced 
 practitioners was to get the teeth of a child into the position 
 they should assume in an adult, and to hold them rigidly in place 
 imtU the child grew up. Thus all expansion and development 
 of the facial bones was hampered, and it is not surprising that 
 they began to revert to their former irregularity as soon as the 
 14 
 
2IO MODERN DENTISTRY 
 
 appliances were removed. The great advance made by Angle 
 and his followers lay in the fundamental idea that the teeth 
 should be made to develop along normal Hnes, and in the for- 
 mulation of a fundamental law that governed such development. 
 Nature's shifting of the permanent teeth into the positions 
 of the temporary teeth during the development of a child is a 
 stupendous engineering feat not surpassed by that of a railroad 
 that changes all its tracks and grades without interrupting 
 traffic. The wonder hes not in the fact that the second teeth 
 should occasionally come in crooked when they replace the first 
 teeth, but that they would ever be able to replace them at all 
 with perfect occluding arches. When it is appreciated that 
 before the child is seven years old, all of the full-sized crowns 
 of the permanent teeth, the wisdom teeth excepted, are packed 
 away in the small face, and that without disturbing mastication 
 or nutrition the roots of the first teeth must be absorbed, and 
 the replacing large second teeth must emerge into graceful lines 
 from their crowded position as the face develops, the wonder of 
 it is beyond comprehension. Such a magnificent engineering 
 feat is worthy of the Master Mind. 
 
 Having grasped the idea that the process of dentition is the 
 result of a wonderful engineering plan, it can then be appreciated 
 that a Httle hardening of the bone by inflammation, or a little 
 extra resistance of the capsule ui eruption, or a httle retardation 
 of bone development by lack of nutrition or disease may readily 
 result in producing discord. Therefore, it is not for the dentist 
 to attempt to pull or push the teeth into adult position, but merely 
 to assist the great plan of nature when accident is obviously 
 retarding or defeating it. A tooth pulled or wrenched from its 
 fully developed socket into a new position in the bone will ob- 
 viously tend to return to that socket; but if durmg the formative 
 stage of the alveolar process, before the permanent socket is 
 estabHshed, the tooth is guided into the normal position, the 
 natural process of development and the focusing of the normal 
 forces of mastication will obviously keep it in position. The 
 dentist must not fight against nature's plan and supplant it 
 with a new one, but he must study the underlying controUing 
 
CHILDREN S TEETH 
 
 211 
 
 factors of dentition and supplement them where necessary. 
 The underlying principles governing successful dentition are 
 comparatively simple if assistance is given before the teeth are 
 fully erupted and their bony alveoli are in the formative stage. 
 The fundamental law is that the full normal width of the arch 
 from sixth-year molar to sixth-year molar must be maintained 
 and that the cusps or planes of the upper teeth should always 
 bite exterior to the respective cusps or planes of the lower teeth; 
 that the anterior cusp of the lower first molar should occlude 
 
 Fig. 123. — Left side of normal arch of a boy of seven years. 
 
 anterior to the upper first molar, and the lower four incisors 
 should always come inside of the upper incisors and be made to 
 evenly assume the full width of the Kne of the arch. If this is 
 accomplished and this position maintained until the permanent 
 lower canines come in unrotated at the extreme ends of the 
 erupted lower incisors, the teeth will be locked in a normal posi- 
 tion and will mold the upper teeth accordingly. 
 
 Case No. i (Figs. 123-125) represents the arches of a boy of 
 seven whose teeth fulfil the law. The formulation of this law 
 has completely revolutionized the science of straightening teeth. 
 
212 MODERN DENTISTRY 
 
 The teeth of young growing children should only be disturbed 
 when they do not conform to the tenets of this law. Teeth that 
 are apparently out of place, but developing along the true plan 
 of dentition should be left undisturbed because they will event- 
 
 Fig. 1 24. — Normal open arches of a boy of seven years. Triangle a-b-c is a 
 valuable guide in determining whether the dental arch is sufficiently wide to insure 
 satisfactory future development. It should be measured either on cast or on the 
 actual arches with a pair of dividers. Base line a-h, extending from the anterior 
 sulci of first permanent upper molars, should exceed by 15 to 20 per cent, either 
 line a-c or h-c, which meet at the median line of the central incisors. 
 
 ually straighten themselves, but if the cutting edge of an upper 
 molar starts to sHp inside the lower arch, or the anterior cusp 
 of the upper first molar starts to slip anterior to the anterior 
 cusp of the lower first molar, or the line of the lower four in- 
 
CHILDREN S TEETH 
 
 213 
 
 cisors is not even and true and inside the upper incisors, then 
 it becomes the duty of the dentist in charge to correct these 
 deformities at once. He must not wait until the canines emerge, 
 nor must he wait until there is a convenient time to accompHsh 
 the work; he must remedy the tendency at once in order that 
 normal dentition may go on undisturbed. In addition to vio- 
 lations of the law just set forth, there may be pathologic bone 
 compHcations or inhibition of bone development, there may be 
 mouth-breathing and adenoids, and various unknown factors 
 
 Fig. 125. — Right side of a normal arch of a boy of seven years. 
 
 of faulty dentition, but in 90 per cent, of the cases of maloc- 
 clusion the sole cause of serious deformity arises because the 
 correct relations of the few teeth essential in the law just quoted 
 are not maintained. 
 
 And so, while it is wise and just that the child who is far 
 advanced in malocclusion should go to the orthodontist who 
 makes a specialty of this branch of dentistry, the prevention 
 of malocclusion should rest with the general practitioner of 
 dentistry, who, watching the child between the ages of four 
 and twelve, should see to it that the first upper permanent 
 
214 MODERN DENTISTRY 
 
 molars bite buccally and posteriorly to the lower first perma- 
 nent molars, that the lower permanent incisors erupt in and 
 maintain an unbroken arch, and that no upper tooth is ever 
 allowed to erupt Hngually to a lower tooth, and that the lower 
 canines erupt unrotated at the extreme ends of the perfect hne 
 of the lower incisors. Since it is the main responsibility of the 
 general practitioner of dentistry to see to it that this funda- 
 mental law is not allowed to be transgressed, it shall now be 
 specifically pointed out just how these tendencies should be 
 corrected, and the times that they usually appear. 
 
 It must not be forgotten that inflammation of the gums 
 and decay of the temporary teeth have a marked influence on 
 the forces governing accurate dentition. If the first teeth decay, 
 and are thereby lessened in width or are lost, the space they 
 should occupy is also lessened, and there is a corresponding 
 tendency for the jaw to be constricted so that the space for the 
 second teeth will be endangered. Also if the pulps of the tempo- 
 rary teeth are diseased or destroyed, the roots do not absorb 
 normally at their appointed time, and thus the normal eruption 
 of the permanent teeth is disturbed. These factors alone may 
 cause malocclusion. Therefore the first and most important 
 obhgation of the dentist is to see that the temporary teeth are 
 kept clean and free from decay. If they are in serious maloc- 
 clusion, and it sometimes happens that they are, it may occasion- 
 ally be necessary to start at the age of four or five to coax them 
 into position, but ordinarily it is better to wait at least until 
 the age of six or seven, when the first permanent molars and the 
 permanent lower incisors have appeared through the gums. 
 This is especially true because a perfectly occluding set of tem- 
 porary teeth does not by any means insure a perfect occlusion 
 of the permanent teeth, and, therefore, if there seems to be a 
 fairly normal line occupied by the temporary teeth it is better 
 to wait; but if the temporary teeth are badly cramped or the 
 lower teeth are biting outside of the upper teeth, expansion of 
 the arch and reduction of the deformity should be started at once. 
 This is especially important, since the permanent teeth lie 
 beneath the temporary teeth, and the adjustment of the tempo- 
 
children's teeth 215 
 
 rary teeth, in many instances, will actually draw the permanent 
 teeth into normal position. Often the case that appears very 
 diflficult, and, without doubt, would develop most unfortunately, 
 with a little study can be remedied at once, or at least so modified 
 that the child will remedy the baneful tendency by its own natural 
 movements in biting. 
 
 Take, for instance, Case 2 (Fig. 126). It is the mouth of a 
 little girl of five years who from thumb-sucking has forced out 
 the upper incisors, and in so doing has pushed back the entire 
 
 Fig. 126. — Case 2, little girl of five years whose jaw has been forced back by 
 thumb-sucking. The molars have the same relative positions on both sides of the 
 jaw. 
 
 lower jaw, as can be seen by the position of the first molars. 
 The extent of the malocclusion is shown by the lines indicating 
 where the true occlusion should be. It looks like a very serious 
 and difficult case, but it was remedied in a very simple, easy way. 
 It was found that if the lower jaw was slipped forward, as in 
 Fig. 127, the deformity instantly disappeared. Bands were fitted 
 and cemented on the lower first molar with wire lugs on the side, 
 and then bands were fitted on the upper molars with extensions 
 that made it impossible for the little girl to close her mouth 
 Unless she kept her jaw forward in the right position. It hap- 
 
2l6 MODERN DENTISTRY 
 
 pened that this Kttle girl had a strong, persistent bite and usually- 
 kept her teeth together, so this simple device entirely remedied 
 her trouble, and the permanent dentition progressed normally. 
 If she had been a mouth-breather with her mouth constantly 
 open, the assistance given by the tendency to keep the teeth 
 together would have been lacking, and the Baker anchorage 
 would have been necessary. This anchorage will be described 
 later on. It was found of great advantage to grind the teeth 
 with an engine stone so that there would be accurate articulation 
 in their new position. This is frequently an essential procedure 
 
 Fig. 127. — Case 2 restored to normal occlusion. 
 
 in such cases, and as the teeth are to be lost later their deformity 
 is of no consequence. When the upper deciduous centrals came 
 out, as they did in a short time, the change to the new position 
 had been easily accepted by the child's jaw and soon became 
 the normal position. 
 
 Case No. 3 (Figs. 128-130), as can be seen, also showed a 
 marked dropping back of the lower jaw with protrusion of the 
 front teeth. In this instance, as the child was only a month or 
 two over four years old, it was decided that it would be dangerous 
 to allow the deformity to increase up to the age of seven. It was 
 found that the lower iaw could be moved forward into proper 
 
children's teeth 
 
 217 
 
 Fig. 128. — Case 3, little girl of four years whose lower jaw has slipped back into 
 posterior occlusion. Right side. 
 
 Fig. 129. — Case 3, little girl of four years whose lower jaw has slipped back into 
 posterior occlusion. Left side. 
 
 position, as in Fig. 131. Therefore, thin caps of pure gold were 
 adjusted to the upper canines, and projections were built on them 
 on the lingual surface with sponge gold and solder so that the 
 
2l8 
 
 MODERN DENTISTRY 
 
 Fig. 130. — Case 3. 
 
 Fig. 131. — Case 3 restored to normal occlusion by gold caps on the canines. 
 
children's teeth 219 
 
 jaws could not go back without striking the projections. In fact, 
 the only way the child could get her teeth together was by keeping 
 the jaw forward in the normal position. This she did so success- 
 fully that when the permanent teeth came in there was hardly 
 any further straightening to be done. 
 
 When, however, as in Case No. 4, the lower second molar 
 on only one side of the jaw is posterior to its upper fellow, the 
 other side being normal, it may be difficult or impossible for the 
 
 Fig. 132. — Case 4, little girl of five years with the second lower molar on only one 
 side in posterior occlusion, the left side being normal. 
 
 child to shift the jaws so that the occlusal planes of both sides 
 will engage normally (Figs. 132, 133). As the Baker anchorage 
 is to be required in any event, it may be simpler to wait until the 
 first permanent molars appear and get them also into position, 
 because, as before stated, when the temporary molars are in 
 normal position such a fact gives no guarantee that the perma- 
 nent molars will likewise erupt in normal position. The only 
 sure fact in these cases is that when the occlusion of the temporary 
 
220 MODERN DENTISTRY 
 
 molars is abnormal the occlusion of the permanent molars will 
 surely be abnormal. 
 
 The next case, No. 5, is t3^ical of a great number, and is an 
 exact reproduction at an older age of the conditions found in 
 Case No. 3. If it is taken in hand properly the irregularity is 
 capable of easy, permanent remedy; while if it is allowed to drift, 
 it is impossible to foretell what deformity may result. Figures 
 134 and 135 show both sides with the lower molars in distal oc- 
 clusion to the upper, while the individual arches in themselves are 
 
 Fig. 133. — Case 4, left side, showing normal occlusion. 
 
 normal in shape. Figure 136 shows the lower jaw extended so 
 that the arches are in good occlusion. Therefore the only thing 
 necessary is to train the jaws and coax the teeth into this position. 
 As the patient had a tendency to keep the mouth open, the method 
 used in Cases 2 and 3 was not available, so the Baker anchorage 
 was used. Since this anchorage is of such importance, a minute 
 description of it wiU now be undertaken. 
 
 Until about twenty years ago it was the writer's habit to 
 make many curious appliances for remedying the defects of 
 
children's teeth 
 
 221 
 
 Fig. 134- 
 
 Fig. 135. 
 Figs. 134, 135. — Case 5, child of eight years. Lower jaw in posterior occlusion to 
 
 upper jaw. 
 
 irregularity, but since then he has accepted the principles and 
 appliances advised by Angle, and therefore the Angle appliances 
 
222 MODERN DENTISTRY 
 
 for accomplishing these results will be described. While, of 
 course, necessary modifications have to be made in each individual 
 case, they should be made according to the principles laid down 
 by Angle. The Baker anchorage consists of appliances shown 
 in Figs. 137 and 138 — an expansion arch and the bands suppHed 
 with screw-thread and nut for attaching them to the teeth. 
 The author finds it better to make a simple band that fits the 
 molars to be moved and to solder the tubes on the side, thus 
 making the appliance smoother to the tongue than if the tight- 
 
 Fig. 136. — Case 5, teeth in normal occlusion, cure being accomplished by the 
 
 Baker anchorage. 
 
 ening screw and nut were used. This band can be cemented 
 into position and the expansion arch adjusted, as shown in Fig. 
 138. Little hooks, like the one shown in Fig. 138, must be sKpped 
 on the upper arch and soft soldered, so that they will be situated 
 just opposite the canines. A couple of ligatures of silk or brass 
 wire should be passed around the arch and incisors so as to keep 
 the arch from bending under the traction strain, and the rubber 
 bands attached as in the illustration. I shall not go minutely 
 into the description of how these Angle appliances are made and 
 
children's teeth 
 
 223 
 
 adjusted, as Angle's works are universally known, and those 
 who desire fuller details are referred to them. 
 
 Suffice it to say, then, that the Baker anchorage was applied, 
 and in a few months the jaws and teeth permanently took the 
 position shown in Fig. 136. Here all the requirements of the 
 
 Fig. 137. — Expansion arch and retention bands devised by Angle. 
 
 fundamental law were fulfilled— the lower molars occluded 
 anterior and lingually to the upper molars, the four lower front 
 teeth in even, full arch occluded Hngually to the upper teeth, and 
 there was every reason to expect the permanent canines to come 
 into proper position at the ends of the four lower incisors, which 
 
224 
 
 MODERN DENTISTRY 
 
 they eventually did, and the case is now developing in good 
 occlusion. 
 
 Fig. 138. — Baker anchorage. 
 
 Case No. 6 is similar to Case No. 5, except that the in- 
 cisors have not scissored past each other, and it required the 
 same appliance and treatment (Figs. 139-141). The molar oc- 
 clusion on the left side was normal. When the lower teeth on 
 
children's teeth 
 
 225 
 
 Fig. 139. — Case 6, right side only in posterior occlusion, necessitating Baker 
 
 anchorage. 
 
 Fig. 140. — Case 6, showing normal occlusion on left side. 
 
 the^right side were coaxed forward judiciously the central and 
 lateral upper incisors dropped naturally and permanently into 
 
 15 
 
226 
 
 MODERN DENTISTRY 
 
 their normal positions. It ought to be stated here that where 
 the upper and lower incisors have scissored past each other 
 beyond the limit of normal occlusion the molars should, if neces- 
 sary, be built up with cement to permit of a normal occlusion 
 of the front teeth. 
 
 u 
 
 fe 
 
 Case No. 7, as seen in Figs. 142-144, is of the same type as 
 Case No. 4, except that the arch of the upper incisors has been 
 broken by the pressure of the upper lip. The same treatment as 
 that of Cases No. 4 and 5 will suffice, except that the broken 
 
children's teeth 
 
 227 
 
 Fig. 142.— Case 7, malocclusion arises in a great degree from irregularity of 
 lower front teeth as well as from the posterior occlusion of left lower permanent 
 molar. 
 
 Fig. 143. — Case 7. 
 
 arch of the upper central and lateral incisors must be restored 
 so that it will fit the lower arch. 
 
228 
 
 MODERN DENTISTRY 
 
 Case No. 8 deals with complications caused by unevenness 
 in the line of the lower permanent incisors. This sort of irregu- 
 larity is, by all odds, the most common and requires the most 
 careful watching on the part of the dentist. It appears between 
 the ages of seven and eight. The permanent molars have erupted 
 and on both sides are in normal occlusion; left side is shown in 
 Fig. 145. It will be noted that where the molars are in proper 
 
 Fig. 144. — Case 7. 
 
 occlusion the loss of the right deciduous molar is a handicap, 
 for the space must be maintained until the permanent bicuspid 
 erupts, but the principal difficulty lies in the reconstruction of 
 the lower arch. In this case expansion arches, as shown in Fig. 
 137, were adjusted on both upper and lower jaws, but the rubber 
 loops were not used, as the permanent molars were in normal 
 
children's teeth 229 
 
 occlusion. The space between the upper temporary canines 
 was widened to permit the occlusion of the full, even arch of the 
 lower incisors and lower temporary canines, which alignment 
 was accompHshed at the same time by simply making the arches 
 the size and shape desired and drawing the teeth to them with 
 loops of twisted silk or brass wire made for the purpose. 
 
 The beauty of such simple appliances is to be found in the 
 fact that they can also be used for retention. Between the ages 
 of six and ten no attempt at permanent retention is sensible, as 
 it retards development. We simply get the teeth into the posi- 
 
 Fig. 145. — Case 8, principal factor of malocclusion is the unevenness of lower 
 
 incisors. 
 
 tion demanded by the law and hold them until they lose their 
 tendency to return to their old position, and then let them go, 
 hoping that the development will proceed along normal lines. 
 I seldom hold any child's teeth in a fixed position for over six 
 months at a time. That is usually sufficient to give them the 
 proper developmental push. The general practitioner of den- 
 tistry is like a riverman guiding a log down the river. He pushes 
 the teeth, when they get jammed or stalled, out into the stream of 
 natural development, and feels that he must constantly watch 
 their progress along the shoals and eddies of childhood and pu- 
 
230 
 
 MODERN DENTISTRY 
 
 berty until they reach the final jam and haven in the perfect 
 arch. And in so doing his task is easier than that of the ortho- 
 dontist. If the general practitioner of dentistry watches each 
 stage of development his work is seldom if ever hkely to involve 
 any but the simplest problems, and will lead to perfect results; 
 while the orthodontist, not ordinarily seeing the child until a 
 
 Fig. 146. — Case 8. Here again we have the triangle laid out showing by the base 
 line a-b that the arch is sufficiently wide. 
 
 deformity is well established, has often titanic difiiculties in a 
 period when developmental forces are slackening, when the bony 
 tissues are mostly formed, for better or for worse, and the demands 
 of school, college, and society are wont to be considered by the 
 parents of far more consequence than the advantages arising 
 from straight arches. In Case 8 the child's appliances were kept 
 
children's teeth 231 
 
 on for six months and the mother was instructed to see that 
 they were kept clean — not "brush them," but see that they were 
 kept clean by examining where the appHances and teeth were 
 dirty and cleansing them with a small brush. At the end of that 
 time the appliances were removed and the development was 
 allowed to proceed, with every chance of the haven of normal 
 occlusion being reached. 
 
 Contraction of the arch is a prominent cause of progressive 
 irregularity both in the mouth and nose, and it should be noted 
 
 Fig. 147. — Case g. Contracted arch. 
 
 and remedied at the earliest moment possible. A safe and practi- 
 cal test to show whether a child's arch should be expanded is to 
 lay out such a triangle as is shown in the upper arch of Figs. 
 146 and 149. Figure 146 represents a normal width, while that 
 of Fig. 149 is contracted. The base line extends between the 
 fossae a-h of the first permanent molars. The triangle sides are 
 obtained by drawing the Knes a-c and h-c to the median Hne at 
 the cutting edge of the central incisors. If there is to be suffi- 
 cient room for the normal alignment of the teeth in the arch the 
 base hne, a-h, should always be from 15 to 20 per cent, greater 
 
232 MODERN DENTISTRY 
 
 than the length of either of the Hnes a-c or h-c. If the upper and 
 lower arches are synchronously expanded by appliances a little 
 too much it will cause no harm, for the erupting teeth will be 
 forced into their proper relations by the pressure of the cheeks, 
 but if the arch is contracted there will not be sufficient space for 
 the imbroken curve of the front teeth. It wiU be noted that al- 
 though Case No. 9 has a contracted arch its treatment is practi- 
 cally similar to that of Case No. 8. 
 
 Let us now take up Case No. 9 (Figs. 147-149). Here we have 
 a condition similar to Case No. 8 except, in addition to the irregu- 
 
 Fig. 148.^ — Case 9. 
 
 larity of the teeth, we have the contracted arch just mentioned. 
 The wire expansion arches were bent so as to give the desired 
 width a-h from molar to molar, and then were put on in the ordi- 
 nary way; then, while the upper and lower deciduous canines 
 were being rotated and pulled into position by means of twisted 
 silk tied to the expansion arch, the natural arches were being 
 spread at the same time by the slow steady spring of the expan- 
 sion arch. If a supplementary spring within the arch is needed 
 in these cases, it can be used. It will be noted that the procedures 
 in all these cases were simple and ordinarily easy of performance 
 
CHILDREN S TEETH 233 
 
 because the regulating was undertaken during the formative 
 period. But had the teeth been allowed to develop along ab- 
 normal hues it is hard to imagine the extent of the irregularities 
 that might have resulted. In all of these cases only one type of 
 
 Fig. 149. — Case 9. Here the base line of the triangle a-b is hardly longer than 
 either of the other two sides, and the arches must be widened 15 or 20 per cent. 
 
 appliance was necessary, namely, the expansion arch, originated 
 by Fauchard and perfected by Angle and Baker. 
 
 Case No. lo, as shown in Figs. 150 and 151, presents a problem 
 almost identical with that of Case No. 8, except that the right lower 
 first permanent molar is in sHghtly distal occlusion to its upper 
 fellow, as shown in Fig. 150, On the left side, which is not shown, 
 
234 
 
 MODERN DENTISTRY 
 
 Fig. 150. 
 
 Fig. 151- 
 Figs 150, 151. — Case 10. Malocclusion largely caused by unevenness of lower in- 
 cisors and the premature loss of right upper first molar. 
 
children's teeth 
 
 235 
 
 Fig. 152. — Case 11, abnormality caused by irregularity of lower incisors. 
 
 Fig. 153.— Case 11. 
 
 the occlusion is normal. As will be seen in Fig. 151, the arch of 
 the upper incisors is good, while the lower incisors are jammed 
 
236 MODERN DENTISTRY 
 
 into a broken line, as was the case with Case No. 8. While it 
 took only three months to permanently remedy the defects of 
 Case No. 8, it took a year and a half to coax the teeth of Case 
 No. 10 into normal occlusion. The difference lay, first, in the fact 
 that the permanent molars of Case No. 8 were in perfect occlusion, 
 
 Fig. 154. — Case 11. 
 
 while the right permanent molars of Case No. 10 were in abnor- 
 mal occlusion. Also the tissues of the child of No. 8 were healthy 
 and showed progressive development, while in the case of No. 10 
 development of the tissues was slow, so that progress in pulling 
 the teeth into shape had to be gradual and tedious. The right 
 lower temporary canine of Case No. 10 was lost too soon from 
 
CHILDREN S TEETH 237 
 
 the strain of moving, necessitating constant care and watching 
 so that the space could be maintained until the permanent canine 
 came into position, and last, but of special consequence, was the 
 fact that the first child in every way possible gave sympathetic 
 assistance, while the second child apparently lay awake nights 
 thinking how she could devise fancy bites that would break 
 the rubber bands and loosen the apparatus. Needless to say 
 progress was very slow until one day the child was caught delib- 
 
 Fig. i55.-^Case 12, irregularity caused by protrusion of the frenum of lip 
 between upper central incisors and also a slipping of left upper teeth inside of left 
 lower teeth. 
 
 erately biting the rubber band that had just been adjusted. It 
 was with difficulty that the indulgent mother was made to realize 
 that the secret antagonism of the child was the chief cause of 
 the slow progress. But when this was reahzed and remedied, 
 the case was finished without undue delay, and it is strongly 
 recommended that all dentists be on their guard against such 
 idios3Tacrasies. - 
 
 Case No. ii (Figs. 152-154) is similar to No. 8. The occlusion 
 of the first permanent molars was normal. The expansion arches 
 
238 MODERN DENTISTRY 
 
 were adjusted, the distance between the canines slowly increased 
 to give room to the lower teeth, and the lower four incisors were 
 moved to a normal, even curve, with the deciduous canines at 
 the ends in their normal positions. 
 
 The irregularity of Case No. 1 2 is due to two factors : First, 
 as is shown in Figs. 155-157, the upper left temporary teeth from 
 
 Fig. 156. — Case 12. 
 
 the canines back are biting inside the lower left temporary teeth; 
 this causes a narrowing of the upper arch, as can be seen by the 
 relatively short line a-b (Fig. 156). This condition can be rem- 
 edied by upper and lower expansion bars. The second factor 
 in this case is a cause of distortion that has not been mentioned 
 before, and that will, if left undisturbed, constantly defeat our 
 
children's teeth 239 
 
 best efforts. This factor is the extension of the frenum of the 
 lip between the upper central incisors in between the two superior 
 maxillary bones, causing a constantly increasing space between 
 the upper central incisors and a tendency for them to rotate. 
 Again we must thank Dr. Angle for the discovery of the cause 
 of this deformity and for the remedy. This frenum must be 
 extirpated, for otherwise the movement of the lip pulling on 
 the spongy tissue between the front teeth will always tend to 
 
 Fig. 157. — Case 12. 
 
 distort them, no matter how often we bring the teeth together 
 and no matter how long we hold them in normal position. 
 
 Extirpation of the Frenum. — Novocain and suprarenin are 
 injected into the frenum, and also deep in between the supe- 
 rior maxillary bones, until the adjacent region is white and insensi- 
 tive. Then the frenum is dissected up to the junction of the gum 
 and lip. After that is done a fissure bur. No. 17 B. & S. gage, is 
 plunged into the articulation of the superior maxillary bones 
 and brought down along the median line until the interdental 
 space between the upper central incisors has been completely 
 
240 MODERN DENTISTRY 
 
 bored out and the membranous junction between the bones 
 has been completely severed and drilled away. It is most impor- 
 tant that the point at which the bur enters should be high up 
 in the median line. After the bleeding has stopped a drop or two 
 of trichloracetic acid can be flowed into the wound to completely 
 cauterize the remaining shreds. After the wound has healed 
 we can then complete the case with the expansion arch, as pre- 
 
 Fig. 158. — Case 12 completed. 
 
 viously described. It wiU be noted from the size of the triangle 
 base that the arch is slightly contracted. Figure 158 represents 
 the case four years later, showing the permanency of the operation. 
 Case No. 13, as is shown in Figs. 159-161, and Case No. 14, 
 Figs. 162, 163, are compHcated by the frenum growing between 
 the upper central incisors. When this is removed, as just de- 
 scribed, there will be no difficulty in making the teeth perma- 
 nently assume their normal occlusion. 
 
children's teeth 
 
 241 
 
 Fig. 159. — Case 13 irregularity caused by frenum of lip growing between upper 
 
 central incisors. 
 
 Fig. 160. — Case 13. 
 
 16 
 
242 
 
 MODERN DENTISTRY 
 
 Impaction of Teeth.— We now come to the discussion of 
 irregularities compKcated or caused by the impactions of perma- 
 nent teeth, as is shown in Case No. 15, Figs. 164-166. This 
 is a very interesting case, and at first glance seems normal. 
 The molars, upper and lower, are in proper occlusion and the 
 teeth appear to be within the influences of their respective 
 planes. But a closer inspection will show that the temporary 
 
 Fig. 161. — Case 
 
 13- 
 
 upper canines are still in position, with great widening of the 
 spaces between the upper lateral and central incisors. An x-ray 
 showed that the permanent canines had been diverted Hngually 
 by the ends of the roots of temporary canines that, unfortunately, 
 were not absorbing normally. The permanent canines, there- 
 fore, were forced within the arch and were being held there by the 
 thick, rigid palatal process of the superior maxillary bones. 
 Figure 164 shows two sHght elevations, marked with rings, beneath 
 
children's teeth 
 
 243 
 
 Fig. 162. — Case 14, complicated by frenum of lip penetrating between upper 
 
 Fig. 163. — Case 14. 
 
244 MODERN DENTISTRY 
 
 which the impacted teeth lie. The patient was a girl of fourteen 
 years. The temporary canines were extracted and the gums 
 and bone over the impacted canines were cut and burred away 
 and the tips of the impacted teeth exposed. This operation was 
 performed under nitrous oxid gas and oxygen, but the author now 
 prefers local anesthesia, as previously described. Trichloracetic 
 acid was applied immediately after the operation, and in two 
 
 Fig. 164. — Case 15, deformity caused by impacted canines. 
 
 days the gum and membrane over the tips of the impacted 
 canines had completely cleared away and the enamel of the 
 canines was in plain view. An expansion arch was then placed 
 on the upper teeth and from it rubber loops were judiciously 
 attached to the laterals, pulling mesially, and also to the first 
 bicuspids, pulling distally toward the molars, and by these rubber 
 ligatures the full space required for the passage of the canines 
 
CHILDREN S TEETH 
 
 245 
 
 Fig. 165.— Case 15. 
 
 Fig. 166. — Case 15. 
 
 from the interior to the exterior of the arch was obtained in due 
 time. Then a How screw was inserted in the lingual plane"* of 
 each canine near the tip, and rubber loops fastened to the screws 
 
246 
 
 MODERN DENTISTRY 
 
 Fig. 167. — Angle device for causing eruption of an unerupted misplaced canine. 
 
 Fig. 168. — Case 16, girl of ten years. Malocclusion caused principally by 
 early loss of temporary teeth, resulting in impaction of upper right canine marked 
 by circle (A) and lower first bicuspid marked by circle (B). 
 
 and carried around the expansion bar and back to the screw. 
 In this way the canines were pulled down and through the space 
 formerly occupied by the deciduous canines that had been ex- 
 
CHILDREN S TEETH 
 
 247 
 
 tracted. When the canines were brought into a position external 
 to the arch the bands were removed and the teeth came into 
 normal occlusion by their own propulsive force. If they had 
 not come properly, the ingenious device of Dr. Angle shown in 
 
 Fig. 169. — Case 16. 
 
 Fig. 167 would have been necessary. When the teeth were 
 erupted the screws were removed and the cavities filled. 
 
 Case No. i6 represents a serious deformity in a Httle girl of 
 ten years arising primarily from the lack of development caused 
 by measles during infancy, and scarlet fever at the age of four. 
 The marks of these diseases can readily be seen by examining 
 
248 MODERN DENTISTRY 
 
 the incisors and canines in Figs. 168-170. In addition to injury 
 done to the unerupted teeth by the skin diseases, it will be noted 
 that irregularity arises primarily from the premature loss of 
 the temporary upper canine on the right side and of the tempo- 
 rary first lower molar on the left side. The loss of these two teeth 
 caused the permanent lateral incisor on the right side to fall 
 toward the first molar, impacting the permanent canine, which is 
 located by the circle A, Figs. 168-170. The loss of the lower left 
 first temporary molar caused a contraction of the arch which 
 
 Fig. 170. — Case 16. 
 
 resulted in the impaction of the first lower bicuspid, as located 
 by the circle B, Figs. 168, 169. The lesson to be learned from 
 this case is twofold: First, if the temporary teeth had been 
 preserved there would have been no malposition; second, if the 
 patient had come for treatment before the age of eight the 
 deformity could have been remedied in months, whereas it took 
 years to bring the teeth permanently into proper position. It 
 will be noted in Figs. 168 and 170 that the first molars are in 
 normal occlusion and in Fig. 169 that the arches are not con- 
 
children's teeth 
 
 249 
 
 Fig. 171.— Case 16. 
 
 Fig. 172. — Case 16, at the age of twelve. 
 
 stricted. The expansion bands were put on and the arches 
 slowly and carefully expanded into normal shape in a period of a 
 
250 
 
 MODERN DENTISTRY 
 
 year and a half. During that time the impacted teeth came 
 through the gum by their own force, as in Case No. 15, and took 
 the desired positions (Figs. 1 71-173), In Fig. 172 it will be noted 
 that a platinum cap has been placed upon the right upper lateral 
 incisor, so as to enable it to maintain itself in the arch by a safe 
 
 Fig. 173. — Case 16. 
 
 occlusion with the lower teeth. Nothing was done except to 
 expand the arches and to make space where the temporary teeth 
 had been prematurely lost. Later on the tips of the incisor and 
 canines were restored by porcelain so that perfect occlusion 
 was obtained as in Figs. 174-176. These casts were taken some 
 years after the case was completed. 
 
CHILDREN S TEETH 
 
 2^1 
 
 Fig. 174.— Case 16, ten years later. 
 
 Fig. 175.— Case 16. 
 
252 
 
 MODERN DENTISTRY 
 
 Fig. 176. — Case 16. 
 
 Fig. 177. — Case 17, irregularity caused by general malnutrition which resulted in 
 a lack of bone development. 
 
 Malnutrition. — Case No. 17 (Figs. 177-179) shows a case of 
 faulty occlusion and lack of development due to malnutrition 
 in the upper jaw. It required three years to expand the upper 
 
CHILDREN S TEETH 
 
 253 
 
 Jaw to symmetry with the lower jaw, which was fairly normal. 
 The malnutrition was caused by measles at the age of four, from 
 the effects of which the child did not recover for years. The 
 child was eight years old when the case was undertaken. Ex- 
 pansion arches were used and the growth of the upper arch 
 stimulated by slow expansion for a period of six months; then 
 the appHance was removed and the bone allowed to develop as 
 it would for another six months. This procedure was repeated 
 
 Fig. 178. — Case 17. 
 
 at six-month intervals for three years, during which time care 
 was taken that the child was properly nourished and given 
 judicious exercise. At the end of this time the jaw was quite 
 normal, and the teeth in good occlusion. This is a striking 
 illustration of the fact that there need be no such thing as a 
 permanently small jaw, from which teeth have to be extracted, 
 if the irregularity is discovered in early childhood. This case 
 proves the fundamental law that the face develops to the teeth, 
 
254 
 
 MODERN DENTISTRY 
 
 not the teeth to the face; and if the teeth are placed in perfect 
 occluding arches during the developmental period there will be a 
 
 Fig. 179. — Case 17. 
 
 Fig. 180. — Case 18, finished case of orthodontia where upper lateral incisors are 
 
 missing. 
 
 corresponding development in the formation of the profile and 
 face generally. 
 
CHILDREN'S TEETH 
 
 25: 
 
 Case No. i8 presents a very interesting complication (Figs. 
 180-182). When the patient was seven years old she was so 
 poorly developed that there was no possibility of the upper jaw 
 ever developing to meet the demands of the dental arch. The 
 lower jaw was fairly normal. In addition to the poor development, 
 the right upper permanent lateral incisor was missing and the 
 left was a mere peg. The restoration of the permanent lateral 
 
 Fig. 181. — Case 18. 
 
 incisors by bridgework was impossible at that age. So the rudi- 
 mentary upper lateral incisor was extracted. This necessitated 
 a corresponding contraction of the lower jaw. The lower first 
 bicuspids were, therefore, extracted. If the lower lateral incisors 
 had been extracted the resulting arch would have been V shaped 
 and would have consequently destroyed the contour of the cheeks. 
 By thus extracting the bicuspids the lower normal arch from 
 
256 MODERN DENTISTRY 
 
 canine to canine was maintained and was the means of making 
 the upper arch appear normal. The upper canines were allowed 
 to come in next to the upper central incisors, and the lower 
 canines and incisors were drawn back until the space formerly- 
 occupied by the incisors was filled. Care was taken that the 
 normal curve of the incisors and canines was maintained. The 
 sharp points were taken off the upper canines so as to make them 
 look somewhat like laterals, and the first bicuspids gave the 
 appearance of very presentable canines. Figures 180-182 show 
 the very satisfactory result. In addition to the adjusting of 
 
 Fig. 182. — Case 18. 
 
 the teeth the child was given a diet containing large amounts 
 of fat and cream, and the necessity of outdoor exercise was 
 emphasized. 
 
 This chapter will be concluded with the reiteration of the 
 fact that the dentist should acquaint himself with the law govern- 
 ing the correct occlusion of children's teeth, and then he should see 
 to it that after the age of seven especially the teeth are made to 
 conform to the law. The distance from fossa to fossa of the 
 first upper permanent molars should be 15 to 20 per cent, more 
 than the distance from the fossa to the median Hne of the central 
 
children's teeth 257 
 
 incisors. The upper teeth must always bite exteriorly to the lower 
 teeth. The first lower molars must occlude anteriorly with the 
 upper first molars, and the lower incisors must occupy an unbroken 
 even curve in the arch, so that the canines will erupt at the ends 
 of the incisor line, occupying their full width in the arch. And if 
 the incisors scissor past each other, judicious filhngs or caps 
 should be placed on the molars, so that the teeth will have space 
 to be brought into proper occlusion. The ingrowing frenum 
 must be eradicated when it appears and the upper teeth coaxed 
 into position if necessary. 
 
 And it is of greatest importance that the child's teeth are 
 kept clean and consequently free from decay, so that the full 
 space occupied by the temporary teeth will be maintained, 
 and so that the roots of the deciduous teeth, instead of becoming 
 infected and necrotic, will remain healthy and admit of normal 
 absorption. 
 17 
 
CHAPTER IX 
 
 CROWNS 
 
 Pin Crowns, Band Crowns, Gold and Porcelain Inlay Crowns. 
 Advantages and Disadvantages of Each 
 
 The artificial crown has been a great blessing and a great 
 curse to mankind. Properly made it is the means by which a 
 broken or decayed tooth is efiiciently and artistically restored to 
 symmetry and usefulness. But if it defies the law of cleanHness 
 and there is not exact gum marginal adjustment, it may be 
 the direct cause of innumerable serious organic diseases. 
 
 Fig. 183. — Pin crown.' 
 
 Band crown. 
 
 Crowns are divided into three classes: the pin crown, the 
 band crown, and the inlay crown. The pin crown is one that 
 depends upon a pin or dowel for attachment to the root, as in 
 Fig. 183. A represents the crown, B the root, C the pin or dowel. 
 The band crown is one that depends for its stabihty on a band 
 attached to the crown that hugs the head of the root like a ferrule, 
 as in Fig. 184. A represents the crown, B the root, C the band, 
 which in this instance is attached to the porcelain crown by a pin. 
 
 258 
 
CROWNS 
 
 259 
 
 The inlay crown is one that is attached to the root by means of 
 an inlay as in Fig. 185. A represents the crown, B the molar 
 
 Fig. 185. — Inlay crown. 
 
 roots, C the inlay that is attached to the crown and enters into 
 the upper body of the root, giving anchorage after the manner 
 
 Fig. 187. — Inlay-band crown: A represents porce- 
 lain crown; B, root with cavity prepared for inlay and gum 
 Fig. 186.— Pin-band margin sloped properly for reception of band; C, gold inlay 
 crown. made in hollow porcelain crown; D, band and gold inlay 
 
 that is to make attachment to root; E, orifice filled in with 
 solder by which upper and lower inlays are soldered to- 
 gether; F, grooves for reception of cement by which fixture 
 is finally secured into position. This method makes it pos- 
 sible to attach porcelain without subjecting it to heat. 
 
 of inlays. Of course, these three methods of attachment are 
 capable of bemg used separately or in various combinations, 
 but we designate the type of crown according to whichever 
 
26o 
 
 MODERN DENTISTRY 
 
 attachment predominates. In addition to the simple pin, band, 
 and inlay crowns, the band and pin can be used in combination 
 (Fig. i86) ; or the inlay and band (Fig. 187) ; or the inlay and pin 
 (Fig. 188). 
 
 The Pin Crown. — ^The pin crown and the inlay crown con- 
 form to the exact contour of the tooth at the gum, and therefore 
 are to be preferred wherever the root is sufhciently strong and 
 large to insure an anchorage that will not compel too great 
 sacrifice of root structure. The band crown, holding as it does 
 from without, will support a weak root against external stress 
 to a remarkable degree, but it has a serious disadvantage in that 
 there is great possibility of its impinging on the gum (Fig. 189), 
 leaving sharp knife edges that lacerate the tissues every time 
 the tooth moves in its elastic peridental membrane under the 
 
 Fig. 188. — Pin-inlay crown 
 
 Fig. 189. — Band crown with improp- 
 erly constructed band. 
 
 shock of mastication. This, of course, need not be so, as will be 
 presently pointed out, but it is a danger against which the best 
 mechanic must always be on his guard, and it is the condition 
 that actually occurs in the vast majority of cases. Theoretically, 
 the band that projects below the gum at the neck of a tooth can, 
 by careful shaping of the root, be made perfectly smooth with 
 the contour of the tooth, but practically this is not so. The 
 root projects from the gum as in Fig. 190. It is therefore im- 
 possible to fit a band to it that will not project into the soft 
 tissues, as in Fig. 191, unless the sides of the head of the root 
 have been carved and trimmed as in Fig. 192, and even then it 
 is always a question whether the band does not project too far, 
 causing the edge to penetrate the surrounding gum and bony 
 tissues. The most expert dentist cannot trim a root and fit a 
 
CROWNS 261 
 
 band under the gum and be sure that the sharp edge of metal 
 does not project enough to cause irritation and consequent 
 infection every time the tooth springs under the impact of 
 mastication. If this is true in the work of the most expert, how 
 surely must it be so with the average operator! Let each dentist 
 remember the ill-fitting bands he has deprecatingly observed 
 on the crowns made by another dentist; let him remember the 
 crowns made by himself that at the time he thought were beauti- 
 fully fitted, but which subsequent events and the forceps per- 
 mitted him to examine out of the mouth, to his mortification 
 and chagrin. 
 
 The fitting of a band to the neck of the root under the gum 
 can be likened to the well-known game of drawing a pig on paper 
 with the eyes closed. The general outHnes of the pig can be 
 
 Fig. 191. Fig. 192. 
 
 drawn with a fair degree of accuracy, but the characteristic 
 details are just as hard to get as are the minute indentations 
 and curves of the root. Yet, in spite of these serious objections, 
 no experienced operator will say that the band crown should never 
 be used. In bridge work or in fractured or badly decayed roots 
 it fills a want at times that can hardly be supplied by any other 
 device. But when we use it let us recognize its dangers and avoid 
 them; let us admit that the best fitting band crown forms a ledge 
 at the gum margin, and the seriousness of this danger will depend 
 entirely upon how thoroughly the patient cleanses the mouth and 
 how prone the oral tissues are to accept contamination. The 
 best way to avoid this danger is to trim the root head to a smooth, 
 slightly sloping cone (Fig. 193), having first built up the root 
 where necessary with amalgam so that it projects above the gum. 
 By this expedient the band can be brought to the gum and not 
 
262 
 
 MODERN DENTISTRY 
 
 below it. And thus, by lifting the free margins of the gum, the 
 edge of the crown can be examined after it is actually cemented 
 into place, and any projection or roughness can be carefully 
 polished away because it can be actually seen. But this pro- 
 cedure will be mentioned later when the methods of making 
 band crowns wUl be discussed more specifically. If, then, the 
 band crown ordinarily has such potentialities for infection, it is 
 incumbent upon us to avoid its use in all crowns whenever 
 sufficient anchorage can be obtained to obviate the danger 
 either of loosening the cement or fracturing the root. 
 
 The anchorage for the simple pin crown can be obtained in 
 every instance where the root is solid and undecayed below the 
 
 Fig. 193. — Decayed or 
 fractured root restored 
 with screw pin and amal- 
 gam. 
 
 Fig. 194. — Pin crown 
 with notch to fit head of 
 root. 
 
 Fig. 195. — Pin crown 
 supported by gold ledge 
 on lingual side of head of 
 root. 
 
 edge of the gum. With the upper central and lateral incisors 
 and canines the face of the root should be formed into a notched 
 wedge, with the notch on the lingual aspect, so that the head 
 of the root will support the front wall against fractures from mas- 
 tication (Fig. 194). A represents finished crown, B the carved 
 root, C the outline of the pin, D the gum Hne. For with the upper 
 incisors and canines the force of mastication is ordinarily applied 
 to the pin crown so as to drive the pin against the front wall of 
 the excavated root, and fractures are frequently the result of such 
 a combination. But if the stress is supported by the notch, as 
 described, or by a ledge (Fig. 195) in the Kngual aspect of the 
 root, the danger of dislodgment through a spHtting of the root 
 is entirely eliminated. A represents the crown, B the carved 
 
CROWNS 
 
 263 
 
 root, C outline of pin, D gum line, E gold support or ledge on 
 back of root. 
 
 The method of making these crowns is as follows: The root 
 is reamed to fit the pin, which should be made of iridioplatinum 
 wire or platinized gold wire, and the head of the root ground, as 
 shown in Fig. 196. Then the pin should be adjusted to the reamed- 
 out root canal and a countersunk crown adjusted and ground so as 
 to closely fit the labial margin of the root, but on the back or 
 lingual aspect a space should be left as shown in Fig. 197. Then 
 the porcelain crown should be removed from the pin to which 
 it is finally to be cemented, and the pin should be removed from 
 the root and barbed with a knife. Then platinum foil, o.ooi inch. 
 
 Fig. 196. — Root notched 
 lingually to receive labial 
 stress of pin crown. 
 
 Fig. 197. — Pin crown 
 in position preparatory 
 to packing in moss fiber 
 gold. 
 
 Fig. 198. — Pin crown 
 in position with moss 
 fiber gold packed in posi- 
 tion, as shown by D. 
 
 or pure gold foil, 0.003 inch, should be burnished to the head of 
 the root and the pin punched through it into the root canal. 
 The pin and foil should then be removed together and soldered. 
 The pin, cap, and porcelain crown should be placed in position, 
 and while the crown is firmly held by the left hand or by an as- 
 sistant, sponge gold should be firmly packed into the space 
 remaining between the crown and the foil resting in the head of 
 the root, as in Fig. 198. A represents the crown, B the root, C 
 the platinum pin shown by the dotted lines, and D represents the 
 sponge gold packed into the aperture between the head of the 
 root covered by the platinum foil and the crown. The porcelain 
 crown is then removed from the pin, and the pin, foil, and con- 
 densed sponge gold, appearing as in Fig. 199, are carefully re- 
 
264 
 
 MODERN DENTISTRY 
 
 moved by a pair of pliers. A little borax is then placed upon the 
 lingual aspect of the sponge gold, as designated by the arrow, 
 and pieces of 2 2 -karat gold solder flowed into the sponge gold 
 that is to go next to the porcelain, otherwise the porcelain when 
 replaced upon it will not fit. The solder should fill the interstices, 
 not encroach upon the outside of the sponge gold except on the 
 lingual aspect, where the small pieces of solder are first laid for 
 fusing. If the sponge gold has been thoroughly packed, as 
 described, there will be no difficulty in removing the pin, plati- 
 num foil, and sponge gold all in one undisturbed piece, and the 
 soldering can be readily done in the Bunsen burner. When 
 the soldering is completed the tooth can be cemented to it (Fig. 
 200). The gold back can then be polished and the crown ce- 
 
 •^ 
 
 Fig. 199. — Pin and 
 gold support against 
 labial stress. 
 
 Fig. 200. — Pin and 
 gold support and porce- 
 lain crown cemented to- 
 gether. 
 
 Fig. 201. — Root ready 
 to receive crown. 
 
 mented to the root with Harvard or silicious cement, as desired. 
 Before finally cementing it into its position on the root it is wise 
 to remove the platinum from the labial portion of the crown so 
 that it may not cause a discoloration after the cement has set. 
 In such a case as this it is well to fill the root canal with Harvard 
 cement and place silicious cement on the face of the porcelain 
 and platinum around the pin. Thus, when the crown is shoved 
 home, we have the adhesiveness of the Harvard cement in the 
 root canal and the insolubility and beauty of the silicious cement 
 to act as an invisible, permanent bond between the root and the 
 cap. Sometimes in making the pin crown it is advisable to make 
 
CROWNS 265 
 
 a stiff shoulder of gold at the lingual edge of the root, instead of a 
 notch in the middle, as in Fig. 202. By this means the entire 
 side thrust of the lower teeth is sustained evenly by the pin and 
 shoulder, making a fracture of the front wall of the root practi- 
 cally impossible. When the root is perfectly strong, and the 
 force of mastication is such as not to make too great a lateral 
 
 Fig. 202.— Pin crown Fig. 203.— Pin crown Fig. 204.— Wedge- 
 
 with gold half cap or with direct occlusion shaped head of root 
 
 band on Imgual side of that makes a strong fix- with adjusted pin crown, 
 
 root. ture. 
 
 strain, as in Fig. 203, a simple porcelain crown with a pin is 
 usually a satisfactory and permanent operation. In such pro- 
 cedures it is wise wherever possible to shape the head of the 
 root in the form of a wedge or with a notch toward the side of 
 the root on which the lateral strain of mastication is to be expected 
 (Fig. 204). For instance, if the occlusion is as shown in Fig. 205, 
 
266 
 
 MODERN DENTISTRY 
 
 the force of mastication will obviously have a lateral stress in 
 the direction of the arrow, and the notch should, therefore, be as 
 indicated, so that it will counteract the stress. If the stress 
 should come on the other side the notch obviously should be 
 trimmed the other way. The pin being separate from the crown 
 is a great advantage in adjusting the porcelain to the head of 
 the root, and with the aid of the modern silicious cements the 
 head of the root and the crown do not have to be so perfectly 
 adapted as formerly. For instance, a crown and root can be 
 
 Fig. 206. — Root and 
 crown roughly notched 
 to increase stability. 
 
 Fig. 205. — Root 
 notched so as to min- 
 imize the danger of frac- 
 ture from side pressure. 
 
 Fig. 207. — Method of 
 cementing a crown and 
 root so that an insoluble 
 cement may be at the 
 crown and root margins, 
 while the more adhesive 
 phosphate of zinc cement 
 may hold the pin in posi- 
 tion to the root. 
 
 shaped approximately as in Fig. 206, and the pin cemented into 
 the porcelain in its proper relation to the root. The silicious 
 cement of the proper color should then be selected and mixed 
 to a doughy consistency, and any good slow-setting phosphate 
 of zinc cement should also be mixed to a creamy consistency 
 and injected into the canal with a Jiffy tube. Then, before 
 the cement can set, the sihcious cement should be placed around 
 the porcelain base of the crown and neck of the pin, and the 
 crown should at once be shoved home, giving an adhesive cement 
 
CROWNS 267 
 
 in the canal against the pin, and an insoluble, invisible cement as 
 a joint where the porcelain and root join, as in Fig. 207. A repre- 
 sents porcelain crown ground to fit approximately the notched 
 root B. C represents the platinum point that extends into the 
 porcelain crown and the root. It should be remembered that 
 real grooves, not scratches, should be made in the root canal and 
 deep nicks in the pin so that the cement will act as a dowel as 
 well as an adhesive. If the occlusion is exaggerated, so that a 
 great side thrust is inevitable, it is sometimes possible and 
 advisable to grind off the lower tooth so as to make the masticat- 
 ing force more end to end. In fact, this should always be done 
 if the simple pin crown is to be used. If a great lateral thrust 
 from mastication is to be expected, the retention shown in Figs. 
 199 and 202 should be used. This principle also apphes to an 
 entire gold pin crown with a porcelain facing, but as the method 
 of making such a crown is so weU known, further explanation 
 is unnecessary. 
 
 Amalgam Crown with Porcelain Facing. — Where there is 
 little or no lateral stress, as in the case of a bicuspid, a useful 
 crown can be made not only easily and rapidly, but, above all, 
 free from gum irritation at the joint of union with the root, even 
 though the root is very frail and badly broken down. The root 
 should be trimmed so that the labial edge is well below the gum. 
 If there is sufficient root to permit the cutting of a wedge in the 
 head, so much the better. The head of the root is first pitted 
 with fine undercuts, and a countersimk pinless bicuspid is then 
 ground so as to fit well under the gum and, at the same time, form 
 a good articulation. Undercuts are then made in the cavity of 
 the tooth with a diamond disk or small sharp carborundum 
 stones. A How screw post is then inserted and cemented into 
 the root and cut off just long enough to support the tooth in 
 proper position. The tooth, pin, and crown are then joined as 
 follows: The cavity of the tooth is filled with soft amalgam; 
 the head of the root and pin are covered with a ball of soft amal- 
 gam; then the tooth is pressed down into position on the root and 
 pin and held there with the left hand, while an instrument in the 
 right hand smoothes the soft amalgam into partial shape. Then, 
 
268 MODERN DENTISTRY 
 
 still holding the tooth firmly with the left hand, a piece of sponge 
 gold should be pressed against the lingual surface of the crown 
 and the two adjacent teeth in such a way as not to interfere 
 with the articulation. The gold at once sucks out the excess 
 mercury and becomes stiff and adherent to the amalgam. At 
 the end of five minutes the patient can be sent away, being cau- 
 tioned not to bite upon the crown for twenty-four hours. When 
 he returns on a later visit the excess amalgam can be trimmed 
 off with fissure burs, files, and sand-paper strips. This method 
 is especially valuable for roots that have been badly broken 
 down through decay, as the metallic salts of the amalgam filter 
 through the weakened root material and seem to have a great 
 preservative power. In such cases it is particularly essential 
 that the occlusion of the opposing cusps should not exert ex- 
 cessive lateral stress. 
 
 Inlay Crowns. — ^This type of crown is particularly adapted 
 to the restoration of molars, and may be used with or without 
 a pin, according to the necessities of the case. The inlay crown 
 reinforced by a pin will be described first. The roof of the pulp 
 chamber of a molar into which the inlay is to project is usually 
 just level with the gingival margin of the enamel. The head of 
 the root should be ground smooth and flat. In this procedure, 
 however, if the crown of the natural tooth has not decayed 
 to the gum level it is rather an advantage that the tooth margins 
 should extend above the gum, so that a greater tooth cup can be 
 obtained for purposes of retention. The pulp chamber and the 
 most available canal should be enlarged as deeply as possible 
 in order to give ample room for the pin and inlay. It is wise 
 to trim the edges of the cavity in the crown so that they will 
 come to the margins, as in Fig. 208, not as in Fig. 209, as much 
 greater stability and strength is obtained by avoiding the sharp 
 angle that may allow the porcelain to chip under the stress of 
 mastication. When the cavity and canal have been prepared 
 according to the lines described, a platinum pin should be inserted 
 into the root canal as far as possible. The pin should then be 
 removed and platinum foil, o.ooi inch, should be swaged into 
 position with bibulous paper and burnished with steel burnishers 
 
CROWNS 
 
 269 
 
 until a perfect matrix of the pulp chamber has been obtained. 
 Then, while the matrix is still in position, the pin should be 
 punched through it well down into the canal. The pui and foil 
 should then be fastened together with hard wax and should then 
 be withdrawn and invested with a mixture of half plaster and 
 fire clay. The investment should be very thin, not over \ inch 
 in thickness. Then porcelain of the desired color should be mixed 
 to the proper consistency, as described in Chapter VIII, and 
 flowed into the matrix around the pin. The wax, of course, 
 should previously have been picked out with a hot instrument 
 or washed out with hot water. In applymg the first portion of 
 porcelain paste care should be taken to keep the edges of the 
 
 Fig. 208. — Proper way of sloping 
 cavity wall in a root for an inlay 
 crown. 
 
 Fig. 209. — Improper way of trim- 
 ming margins of cavity in root where 
 an inlay crown is to be used. 
 
 platinum matrix free from the paste to allow of a further adap- 
 tation of the metal. When the first fusing has been accomplished 
 by placing the invested pin and matrix in the furnace, a second 
 application of porcelain may be necessary to completely fill the 
 mold and fuse the pin firmly into position, on account of the 
 shrinkage of the first supply of porcelain body. When the pin 
 and matrix are thoroughly fused together in proper relationship 
 by the porcelain, the investment should be broken away and 
 cleansed from the pin and matrix, and the fixture placed again 
 in position in the mouth, where the free edges of the matrix 
 should be given an additional burnish to secure accurate adap- 
 tation. With the matrix in place an impression should be taken 
 of the adjacent teeth. Wax should then be flowed over the pin 
 
270 MODERN DENTISTRY 
 
 and under side of the matrix to permit of easy removal; and a 
 model cast with the pin and matrix in place. When the model 
 is obtained a slight amount of heat applied to the platinum 
 matrix and pin will permit of easy removal. The pin can be 
 cut off to the proper length and the crown built up according 
 to the necessities of color and bite, using the model as a guide. 
 Figures 210 and 211 show the finished crown and the outlines of 
 the cavity in the prepared root. Carved crowns are frequently 
 the most artistic when made by an expert porcelain worker, 
 but ordinarily the dentist will get the best results by making use 
 of a manufactured facing or tooth such as is designed for vul- 
 canite work. The tooth can be selected both for color and size, 
 and can be ground and fused into position with the porcelain 
 
 Fig. 210. — Inlay crown with pin. Fig. 211. — Inlay crown and pin in posi- 
 
 tion on root. 
 
 as desired. Before the edges of the platinum matrix are covered 
 by the last fusing it will frequently be advisable to burnish them 
 finally in the mouth on the edges of the root to ensure perfect 
 adaptation. Before the tooth is set the platinum matrix should 
 be removed, the pin roughened and the cavity undercut, as 
 previously stated. Above every other consideration, the dowel 
 principle should be maintained by using genuine grooves in the 
 tooth cavity that is to hold the crown. The method of using 
 silicious cement on the edges and phosphate of zinc within is 
 also advisable. It should not be forgotten that the chief support 
 of this crown lies not in the pin, but in the inlay of porcelain 
 that fills the enlarged pulp chamber. If two pins are deemed 
 advisable, they can be used if they are not too long, and if the 
 
CROWNS 271 
 
 pulpal openings of the canals are sufficiently enlarged to make it 
 possible to overcome the divergence of the canals. If it is desired 
 to make these molar crowns without the use of a model the fol- 
 lowing method can be employed, and, as a matter of fact, an 
 experienced porcelain worker seldom uses a model. When the 
 matrix and pin are stiffened with porcelain, as herein described, 
 a countersunk tooth, such as is used for vulcanite work, of the 
 proper size and color, may be roughly ground to fit the head of 
 the root and bite. The pins of the tooth should be cut away and 
 the countersunk portion filled with porcelain paste. The tooth 
 can then be placed in its proper position 
 on the platinum matrix and fused, care r^ N^ A 
 
 being taken, as before stated, to leave W "n 
 
 the platinum edges free for final burn- — A "' f 
 
 ishing and finishing. Instead of using y 1 
 
 a manufactured tooth, however, the / /\ I 
 
 experienced worker will usually build / / / 
 
 the tooth up with porcelain, molding [y [y 
 
 it into shape where necessary, and carv- p.- 212.— Simple inlay 
 ing it after the final fusing to give the crown. 
 
 proper bite and contour. 
 
 As before stated, with an inlay crown the mass of porcelain 
 within the cavity is the chief source of retention, and, therefore, 
 it is sometimes difficult to know whether one is inserting an inlay 
 or crown. For instance, in a case such as is shown in Fig. 212, 
 is it an inlay or a crown that is required? The broken tooth has 
 left a little more than a third of the natural crown. The dotted 
 line shows the size of the inlay and its outline. Before the days 
 of insoluble, invisible silicious cements such a tooth would ordi- 
 narily have been cut down to the gum margins to conceal from 
 the patient's eye, and perhaps the shrinking eye of the dentist, 
 the unsightly edge that was sure to appear in the course of a 
 year or two; but now, with the aid of these cements, no such 
 fear need restrain us from putting our edges boldly above the 
 gum, knowing that a moderate amount of skill, and an eye 
 fairly exact in the selection of colors, will enable the operator to 
 make a cleanly, inconspicuous operation. A porcelain filling 
 
272 
 
 MODERN DENTISTRY 
 
 ought to be inconspicuous at the distance of 6 inches, and, as a 
 bright girl once said, "If anyone gets closer than that he won't 
 see it anyway." If the sides of the tooth are decayed well down 
 to the gum on all sides, the pin is an advantage, but if the tooth 
 is only partly gone, the porcelain crown or inlay, as just described, 
 can be made without the pm, the deep, sloping cavity walls 
 being a sufficient source of retention. 
 
 When there is unusual stress in mastication, and the color of 
 the filling is not an objection, the gold inlay or crown can be 
 quickly and readily made by a modification of the method 
 just described. The cavity in the tooth is prepared as in Figs. 
 211 and 212, and gold, 0.003 inch, is used for the matrix instead 
 of platinum. While the matrix is in position the pin is punched 
 through it into the root canal and the cavity packed with sponge 
 gold until the matrix and pin are firmly joined together. The 
 matrix and pin should then be teased out by gently raising 
 the sides of the matrix, first on one edge and then on the other. 
 When it has been removed the pin can be seized with a pair of 
 pliers and 22-karat solder can be flowed into the sponge gold. 
 Then the fiUed matrix and pin can be replaced in position and the 
 edges burnished, when more sponge gold can be added and more 
 solder used until the complete gold crown has been made; or, 
 if desired, a porcelain top can be adjusted in any one of the 
 numerous ways known to the mechanical dentist. 
 
 The Band Crown. — We now come to the band crown — the 
 malefactor — and yet in many instances the only resource. For, 
 as before stated, when it extends below the gum its benefit is 
 problematic, but when its edge is at or above the gum margins 
 it is a tower of strength and stabihty. For instance, take the 
 case of a. superior upper incisor that has lost its pulp and has 
 been so seriously discolored that its appearance is hopelessly 
 ruined, while its intrinsic stability is so undermined by decay 
 that a pin crown would be ill-advised. In such a case the band 
 crown is called for (Fig. 213). The cementum is the healthiest 
 structure of the whole tooth, and the only possible means of 
 preserving the root is to fill it up boldly and then to band it. 
 The first essential, of course, must be perfect sterilization and 
 
CROWNS 
 
 273 
 
 cleansing of the root canal, followed by careful sealing of the tip 
 with gutta-percha. When this has been accomplished, as de- 
 scribed in Chapter VI, the entire interior of the root and tooth 
 should be filled with amalgam. In cases where decay has pro- 
 gressed to a very extensive degree a How screw may be inserted 
 in the canal and the amalgam packed around it and the excess 
 mercury extracted with sponge gold. The amalgam is useful 
 in arresting decay by the infiltration of its salts into the tooth 
 substance, although it sometimes has also an unfortunate ten- 
 dency to turn the root black, so that any portion of root appear- 
 ing above the gum is conspicuous. When, therefore, the weak- 
 ened tooth or root has been properly sterilized and filled, as just 
 
 Fig. 213. — Broken-down central in- 
 cisor root to be banded and crowned. 
 
 Fig. 214. — Broken-down incisor 
 root built up with a screw and amalgam 
 ready for banding. 
 
 described, it must be shaped at the gum margin with slightly 
 conical sides, as shown in Fig. 214. A bevel edge 0.05 inch in 
 extent is ample retention for a crown if the band fits accurately 
 and is rigid enough to withstand the stretching force of masti- 
 cation. When platinum or gold is used No. 30 B. & S. gage is 
 strong enough for a band that averages -g- inch in diameter. 
 All bands exceeding that size should be No. 29 gage, which 
 thickness will be strong enough to give stability to any crown. 
 The great advantage of a simple crown band on a 0.05 inch bevel 
 lies in the fact that if at any time the porcelain facing chips or 
 spKnters away and requires repairing, a strong pull away from 
 the gum fine with a heavy enamel scaler will easily dislodge it. 
 
274 
 
 MODERN DENTISTRY 
 
 and make the repair simple for the dentist and of great ease for 
 the patient. Where this procedure is not feasible, through a 
 too great adherence of the cement, a small cut in the edge of the 
 band will make its removal easy, and the cut in the band can be 
 readily soldered before the tooth is finally repaired. The direct 
 tension away from the root is never exerted in the act of masti- 
 cation, and therefore such a possibility of easy removal does not 
 mean that the band crown will not be amply able to withstand the 
 stress of chewing without being dislodged. Unfortunately, how- 
 ever, there is no operation that has not its percentage of failures, 
 but it can be safely said that if a band accurately fits a slightly 
 conical head of a root, and is cemented on with proper regard 
 for the dowel action of the cement and care as to dryness, there 
 
 @ 
 
 Fig. 215. — Head of instru- Fig. 216. — Instrument with wire loop in- 
 
 ment to receive wire loop for serted ready to be slipped around head of 
 
 measuring circumference of root, 
 root prepared for banding. 
 
 is no reason why the crown should not remain firmly attached. 
 The failures usually arise from the fact that the band does 
 not quite fit, or that it is too thin and stretches, or that the 
 cement is not properly mixed, or last, and most frequently, 
 moisture creeps in between the root and cement while the crown 
 is being set in position. 
 
 The first band crown that will be described is the crown 
 consisting of a platinum band for a base, with a covering of 
 porcelain built and baked upon it. The method of procedure 
 is extremely simple when the art of mixing and baking porcelain 
 is mastered. Take, for example, the construction of an upper 
 incisor, as shown in Fig. 214. The figure represents the frontal 
 aspect of a broken-down upper central incisor, where the root 
 canal has been filled and the conical top of the root has been 
 
CROWNS 
 
 275 
 
 prepared. A represents a screw which has been inserted into 
 the root, B the amalgam which has been packed into root and 
 around the screw, C the projecting stump composed of amalgam 
 and root, D the adjacent upper central incisor, and E the adja- 
 cent upper lateral incisor. The measure of the base of the cone 
 is taken with No. 30 brass wire as follows: Figure 216 represents 
 
 :^sdKO 
 
 Fig. 217. — Wire loop drawn tight and removed from head of root. 
 
 a steel rod with two holes drilled from the opposite sides to a 
 common orifice in the end (Fig. 215). The wire is passed through 
 these holes, forming a loop. When this has been accomplished 
 the loop is passed around the root near the gum, and the loose 
 ends drawn upon it until the loop approximately encircles and 
 fits the root. Then the rod is slowly revolved until a closely 
 fitting wire ring fastened by a couple of twists is the result. The 
 
 -^Kiy 
 
 Fig. 218. — ^Loop split and straightened 
 to show length metal should be cut to form 
 band. 
 
 Fig. 219. — Platinum band fitted 
 to root preparatory to making 
 porcelain crown. 
 
 loop is then slipped off the root, cut with a pair of scissors and 
 straightened out, so that it resembles Fig. 218 and gives the exact 
 size of the circumference of the band to be used. The strip of 
 platinum for the band should then be cut either of No. 30 or No. 
 29 gage, according to the size of the root, and of a width a httle 
 less than the entire length that the finished tooth is to possess. 
 
276 
 
 MODERN DENTISTRY 
 
 The band should be made 0.02 inch shorter than the wire. The 
 ends of the piece of cut platinum should now be brought together 
 with a slight lap, soldered with pure gold and hammered so that 
 the soldered ends will be even and level with the rest of the band. 
 The band is now ready for adjustment to the root. The band 
 should now be pressed upon the root, jamming and stretching 
 it upon the cone until it fits the root evenly all around, and touches 
 the gum but does not impinge or go under it. When the band 
 is being fitted it should be cut away with an engine stone where 
 it impinges so that it will finally fit without lacerating the tissues. 
 At this point it resembles Fig. 219. The band should then be 
 compressed near the cutting edge until it fills up the space the 
 
 Fig. 220. — Band compressed at 
 cutting edge to fill space between 
 teeth. 
 
 Fig. 221. — Platirium band trimmed 
 labially preparatory to final shaping to 
 receive porcelain finish. 
 
 finished tooth is to occupy, as in Fig. 220. Then a curved piece 
 of platinum is cut out of the labial side, as in Fig. 221, and a 
 cut made in the labial portion that is left, that will reach to the 
 top of the root. When this has been done the platinum on the 
 labial side should be boldly pressed down over the head of the 
 root, and ground and molded so as to form a complete skeleton 
 cap that will firmly fit the root and occluding bite, and yet will 
 allow ample space for the porcelain that is now to be added, 
 according to the color and size desired. The side view of the 
 cap is now as seen in Fig. 222. The cap is now removed and is 
 ready for the porcelain, that should be added as described in 
 Chapter VII, until it res{;mbles Fig. 223. The dotted hues A 
 
CROWNS 277 
 
 show the porcelain that enters within the body of the cap for 
 purposes of retention ; B represents the porcelain face of the tooth 
 when the process is completed. When the platinum cap has been 
 made, its completion with the porcelain bodies is extremely 
 simple and easy. The color in the shade guide should be chosen ; 
 the mixture made according to the formula, care being taken in 
 this work to add a little extra yellow to counteract the blue of 
 the underlying platinum. The first baking should be made 
 from the tip down to the hollowed-out portion of the cap. The 
 second and third bakings should cover the entire anterior surface 
 of the completed tooth. In the last baking, where the shghtest 
 excess of baking would cause the platinum underneath to show 
 
 Fig. 222. — Cross-section side view Fig. 223. — Porcelain central incisor 
 of platinum cap ready to receive with platinum base, 
 
 porcelain covering. 
 
 through and spoil the color, it is wise to bake very slowly and to 
 stop while the final surface is still slightly granular. This can 
 readily be gone over with a sand-paper disk, and the porcelain 
 will take a beautiful polish, and yet will prevent the blue color 
 of the platinum beneath from showing through. As before 
 stated, care should be taken to see that the band crown is set 
 with great care as to dryness and regard for the dowel effect 
 of the cement. Sometimes if the band cannot readily reach 
 the labial aspect of the gum, and the fine of the band and root 
 is disconcertingly evident, it is good practice to cut this line 
 out with a fissure bur or inverted cone bur, and fill in the space 
 with a well-chosen silicious cement that will completely conceal 
 
278 
 
 MODERN DENTISTRY 
 
 the edge of the rim and make a smooth, even contour with the 
 root and the crown. 
 
 In making a bicuspid or molar the same principle and pro- 
 cedure hold, with a few necessary, slight modifications. In either 
 
 Fig. 224. — Bicuspid prepared to 
 receive platinum band for porcelain 
 
 Fig. 225. — Side view of platinum shell 
 and band for porcelain bicuspid. 
 
 case the head of the root should be trimmed to a cone, as pre- 
 viously described, care being taken not to allow the band to 
 extend beyond the bevel of the root into the gum. The width 
 of the band should not come up to the occluding tooth and should 
 
 Fig. 226. — Platinum shell and band for porcelain crown in its relation to adjacent 
 
 teeth. 
 
 be short enough to allow a generous covering of porcelain. The 
 greater the body of porcelain, the less likelihood is there of frac- 
 ture from mastication. For instance, Fig. 224 represents a bicus- 
 pid root that has been prepared for a platinum band filled with 
 
CROWNS 
 
 279 
 
 porcelain. Figure 225 represents the three-quarter aspect 
 showing the band in position. A shows flap of platinum bent over 
 on the head of the root C to form a partial cup to receive the 
 porcelain, B shows sides of the band. Figure 226 shows the 
 buccal aspect of the same crown and band. B represents the 
 upper part of the band with the edges spread so as to make good 
 approximal contact with the adjacent tooth, C represents the 
 exposed root, and A the flap turned in to make the cup for the 
 porcelain. The method of procedure in applying the porcelain 
 is exactly the same as with the central incisor, previously de- 
 scribed. However, with the bicuspids and molars great care 
 
 Fig. 227. — Molar root trimmed 
 for adjustment of gold crown with a 
 porcelain face. 
 
 Fig. 228. — Gold band in position. 
 Dotted line shows the head of the root. 
 Band should be cut off at this line and 
 a top adjusted. 
 
 must be taken with the grindmg surface to reproduce the cusps 
 and contours. 
 
 If it is desired to make a gold cap with a porcelain facing 
 the procedure is obvious to those who know the ordmary proc- 
 esses of crown and bridge work. Yet it might not be out of 
 place to briefly describe one of the simpler methods. Let us 
 take, for example, a molar root that has been prepared for the 
 crown, as in Fig. 227. The band is prepared of No. 29 gage 
 gold plate composed of 22 parts gold, i of copper, and i of silver. 
 The root with the band in position appears as in Fig. 228. The 
 dotted line represents the position of the top of the root. The 
 band is now ground level with the root top while it is in position; 
 it is then removed and a piece of pure gold plate. No. 30, is sol- 
 
28o 
 
 MODERN DENTISTRY 
 
 dered on top with 2 2 -karat solder, trimmed evenly, and polished. 
 When the cap is replaced in position the pure gold can be bur- 
 nished and worked with broad-faced pluggers until it absolutely 
 fits the upper surface of the root. Then, as is shown in Fig. 229, a 
 porcelain facing, B, with platinum pins is ground to fit the buccal 
 edge of the cap A. The facing is backed with pure gold and 
 fastened to the cap with hard wax, C. The bite is contoured 
 in wax and reproduced in gold in any of the numerous ways 
 commonly known. When a complete gold sheU is desired, and 
 the question of color is of no consequence, the making of a gold 
 crown is a question of a few minutes from the time the root has 
 been properly filled and prepared. Let Fig. 230 represent such 
 
 Fig. 229. — Ordinary porce- 
 lain-faced gold band crown 
 properly adjusted to root. 
 
 Fig. 230. — Root trimmed for adjustment of gold 
 shell crown. 
 
 a molar root. The band should be made of No. 29 gage gold 
 plate, as previously described. The proper measurement should 
 be made with a brass wire and the band cut 0.02 inch short. 
 The ends of the band should then be brought together with a 
 slight lap, powdered borax placed upon the Kne of juncture, 
 and the band held in a Bunsen burner until the two ends are 
 sweated together. The joint should then be hammered even, 
 and we have a seamless collar the right size for the work. This 
 should then be pressed down upon the root and fitted to the gum, 
 as just described. The occlusal edge should also be ground so 
 as just to miss the opposing teeth, the sides also should be bulged 
 and jammed out so that they make proper contact with the 
 
CROWNS 
 
 adjacent teeth and protect the approximal space on each side. 
 Then we have the band assuming a position such as is shown in 
 Fig. 231. When this has been accomplished a suitable mold 
 is chosen from a die plate containing inlay impressions of tooth 
 cusps. A top for the crown is swaged of pure gold No. 30 B. & S. 
 gage. This top is then fitted approximately to the band and 
 tacked into position on four sides with 22-karat solder, care 
 being taken that it is sufficiently high to reach the occluding 
 tooth and that the solder used for tacking it into position does 
 not get upon the gold cusps, rendering them stiff and rigid. 
 When this has been done the 
 crown is filled with soft wax and 
 placed in position on the root. 
 The patient is then told to sink 
 his teeth into it and to swing the 
 jaw so as to get a perfect plane 
 of mastication. The soft gold 
 yields to the pressure and per- 
 fectly occluding cusps are quickly 
 formed. If the gold is driven 
 down too far it must be raised in 
 that particular spot by a broad- 
 faced plugger. So far the crown 
 consists of a well-fitting band 
 and perfectly occluding cusps 
 made in thin gold. It is taken off 
 the root, the wax removed, and 
 sponge gold packed into the 
 inside of the crown next to the grinding surface, so that it makes 
 the grinding surface at least T2 inch in thickness. This can 
 can readily be done without distorting the soft gold face. Pow- 
 dered borax can now be sprinkled within the gold cap, pieces of 
 22-karat solder added, and the whole appHance held in a Bunsen 
 burner until the interstices of the sponge gold are filled. This 
 crown can then be polished and set in position in the usual way, 
 care being taken not to polish the side so as to destroy the firm 
 union of the crown with the contact points of the adjacent teeth. 
 
 Fig. 231. — Gold band adjusted to 
 root and adjacent teeth ready for soft 
 gold top, into which the occluding 
 teeth are to be bitten to make a per- 
 fect and easily adapted bite. 
 
CHAPTER X 
 THE REPLACING OF LOST TEETH 
 
 The Attached Bridge. The Removable Bridge. 
 
 The Attached Bridge. — As has previously been stated, a 
 bridge that cannot be kept clean should never be placed in the 
 mouth. Many pieces of removable bridge work attached by 
 telescope crowns are so bulky and badly constructed at the gum 
 margin that although the bridge itself can be cleansed, never- 
 theless the inner crowns, by their impingement on the gum 
 tissues, are a constant menace to the health of the mouth tissues 
 and a possible source of general infection throughout the body. 
 On general principles, therefore, the simplest appliances consist- 
 ent with strength and durability are to be preferred. 
 
 The replacement of a single incisor or canine, where the teeth 
 on both sides are normal and sound, has been considered the 
 bete noire of dentistry. It has generally been associated with 
 extensive banding and crowning of one or both adjacent teeth, 
 and only too frequently the procedure has been followed by 
 inflammation and infection of the gums around the abutments. 
 As a matter of fact, there need be no difi&culty in making a useful, 
 permanent, natural, and cleanly fixture for the replacement of 
 such a tooth. Take, for instance, the restoration of an upper 
 central incisor where the other central and the adjacent lateral 
 incisors are normal. The procedure is as follows: The pulp in 
 one tooth is removed, the canal tip filled as described in Chapter 
 VI. Then the canal is reamed out and a piece of iridioplatinum 
 or platinized gold wire. No. 14 or 16 B. & S. gage, is inserted 
 in the canal as far as possible. The wire is then bent at right 
 angles across the space and the end fitted into a shallow groove 
 that has been made in the lingualaspect of the other tooth. 
 
THE REPLACING OF LOST TEETH 
 
 283 
 
 The wire abutment must be set so as to avoid the bite of the 
 occluding lower teeth. A porcelain dummy that fits the gum 
 and has a suitable color is then soldered to the bar in the usual 
 way, and the whole appliance is cemented into position, one side 
 being attached and the other free. In this way it is possible 
 for the fioss-silk to be passed under the loose end of the bar, 
 insuring perfect cleanliness. It is essential to carve the porce- 
 lain dummy so that it will conform to the characteristics of the 
 adjacent teeth, as shape is even more important as a means of 
 concealment than color. In cementing the appliance into place 
 the lower portion of the canal should be filled with phosphate 
 cement, and silicious cement should be placed around the pin 
 
 Fig. 232. — Missing upper central 
 incisor. Ordinarily considered most 
 difficult to replace. 
 
 Fig. 233. — Preparation of teeth 
 for replacement of missing upper cen- 
 tral incisor. 
 
 where it emerges from the tooth. The appliance when set will 
 thus have an adhesive cement holding the pin in the tooth, while 
 the insoluble silicious cement wiU seal the orifice of the canal 
 around the pin. 
 
 The procedure is shown as follows: Let Fig. 232 represent the 
 lingual aspect of the case in question. Figure 233 represents 
 the central incisor opened up, its pulp removed, and the pulp 
 chamber sterilized and filled at the tip, and with a groove in the 
 enamel running off the orifice of the pulp canal to receive the 
 platinum bar as it spans the space between the two teeth. The 
 end of the bar rests in the shallow groove shown in the lingual 
 face of the lateral incisor. Figure 234 shows the bar in position, 
 
284 MODERN DENTISTRY 
 
 and the facing ground and backed with pure gold ready to be 
 fastened on the bar with hard wax, so that the appliance can be 
 removed and soldered. Figure 235 represents the finished ap- 
 pliance ready for setting with cement. The curved lines repre- 
 sent the solder which gives the Hngual contour and unites the bar 
 firmly to the tooth. As the tendency of the bite of the lower 
 teeth is to keep the loose end of the bar in its position in the 
 groove, this appliance usually gives perfect satisfaction. And as 
 the floss-silk can be passed between the pin and the lateral in- 
 cisor, and under the fixture across the gum, there is no difiiculty 
 in keeping such an appliance as clean as a natural tooth. The 
 groove in the lateral incisor that receives the bar usually does 
 
 Fig. 234. — Lingual view of assem- Fig. 235. — Bridge to replace lost upper 
 bled bridge to replace lost upper cen- central incisor, 
 
 tral incisor. 
 
 not go completely through the enamel, but if it does, a shallow 
 inlay of gold can be inserted containing a groove; or the cavity can 
 be undercut and filled with insoluble siHcious cement, in which 
 the groove for the tip of the bar can be made. In any case there 
 will be no tendency for decay to start under the bar if the sur- 
 face is swept daily with floss-silk. In fact, enamel will not be 
 decayed by any colony of bacteria that is less than a day old. 
 Decay results because the colony is not removed daily, and usually 
 remains undisturbed week in and week out. Decay is primarily 
 the result of undisturbed filth, and if the refined members of 
 society would be one-quarter as careful of the cleanliness of their 
 mouths as they are of keeping their persons clean, decay of their 
 teeth would soon be unknown. 
 
THE REPLACING OF LOST TEETH 285 
 
 The next bridge described will be the restoration of a missing 
 bicuspid or molar by an immovably attached fixture, where the 
 teeth on both sides are sound. This is the inlay cantilever bridge, 
 that depends upon a gold inlay and pin inserted into the pulp 
 chamber as a means of retention. Instead of demanding the 
 removal of all the enamel from the abutment the construction 
 demands the preservation of the enamel for its strengthening 
 quality and its beauty of appearance. If the pulp has previously 
 been destroyed and the canals filled aseptically, so much the 
 better. Described in a few words, the bridge consists of a gold 
 inlay through which a bar projects into the root canal of the 
 abutment tooth, which bar also extends across the gap to a 
 groove on the edge of the occlusal surface of the other abutment. 
 The porcelain facing or dummy is soldered to this bar. In fact, 
 this bridge is similar in principle to the incisor bridge just de- 
 scribed, except that the broad masticating surface of the dummy 
 gives a tipping tendency, which is overcome by making the gold 
 inlay extend into and over the grinding surface of the stationary 
 abutment. If there is a filHng in the approximal grinding surface 
 of the molar that is to act as an abutment so much the better; 
 if not, a cavity should be cut out sufficiently large, but not large 
 enough to let the gold obviously show when the bridge is cemented 
 into position. The cavity should extend well toward the gum 
 line if the tooth is perfectly sound ; and if the enamel at the base 
 of the cavity seems at all infected it is better to let the cavity 
 extend to the cementum. Then, when the cavity has been pre- 
 pared with straight, slightly sloping sides. No. 14 platinum wire 
 should be filed to a suitable point and fitted as deeply as pos- 
 sible into the most available root canal of the molar, the canal 
 having been previously prepared to receive it. Then the wire 
 should be bent to extend across to the face of the first bicuspid, 
 where a convenient groove has been prepared, such as has been 
 previously described. For instance, Fig. 236 represents the side 
 view of the molar with the outhne of cavity shown in dotted 
 lines, and with the platinum or gold bar extending across the 
 space to be bridged. Figure 237 shows the full occlusal view, 
 A showing the grinding surface of the bicuspid, B the grinding 
 
286 MODERN DENTISTRY 
 
 surface of the molar, with outlined cavity containing the bar 
 that projects across the space to be bridged, and rests in the 
 groove on the occlusal surface of the bicuspid. This groove 
 ordinarily should not be made deeper than one-half the thickness 
 of the enamel. 
 
 Fig. 236. — Pin and bar in position for attachment of a bicuspid dummy. 
 
 When the bar has been accurately adjusted and removed, 
 gold foil 0.003 inch in thickness should be burnished into the 
 cavity of the molar until a perfect matrix is formed — if the bot- 
 tom of the matrix is punched through it is of small consequence. 
 When the matrix is completed and in position, the pointed 
 platinum wire should be punched through the bottom of the 
 
 Fig. 237. — Occlusal view of bar in position running into lingual root of molar. 
 Dummy with a porcelain face is to be soldered to the bar to replace lost bicus- 
 pid. 
 
 matrix into the root canal prepared for it, and the extension 
 fitted accurately into position in the groove of the bicuspid. 
 When this has been done, sponge gold should be firmly packed 
 into the matrix around the bar, building it almost up to the 
 matrix edges. If a little moisture gets into the matrix it does not, 
 of necessity, interfere with the operation. When the gold is hard 
 
THE REPLACING OP LOST TEETH 287 
 
 and condensed the entire piece may be removed by grasping 
 the cross-bar with a pair of pliers, and then the matrix, sponge 
 gold, and bar can be readily soldered together with borax and 22- 
 karat solder. This can easily be done, without investment, in 
 an ordinary Bunsen burner, the only care required being that the 
 solder should be placed upon the sponge gold and not allowed 
 to flow upon the outside surface of the matrix, for such an acci- 
 dent will prevent the inlay from fitting accurately. When the 
 piece is cold it should be replaced in the cavity and the entire 
 matrix edges burnished to position, and the bar bent back into 
 
 Fig. 238. — Cantilever bridge with porcelain side and grinding surface designed 
 to replace lost bicuspid. Attachment is made to bicuspid by pin A and gold inlay 
 B. A pin in gold cup C holds the porcelain tooth firmly when cemented into 
 position, and the spud D rests upon the molar, giving firm support on the unfas- 
 tened side of bridge. The figure on the right represents the under side of the 
 porcelain tooth with the hole for the pin. 
 
 its proper place, if it has been slightly distorted during the first 
 removal. More sponge gold and solder can now be added until 
 the inlay has the proper occlusion. After the second soldering 
 the inlay should be placed in position, and the porcelain dummy 
 ground, adjusted, and waxed into position. The fixture can then 
 be removed and the dummy soldered to the pin and inlay. The 
 bridge is then ready to be cemented into place. If it is a lower 
 molar that is to be used for an abutment, the posterior canal 
 should be used to receive the pin. In such a case, in order to 
 avoid a displa}'- of gold, a full-faced porcelain tooth should be 
 used. It should be cemented into a gold cup which spans the 
 
288 MODERN DENTISTRY 
 
 space between the inlay in the molar and the tooth on which 
 the spud rests. The spud, of course, in this instance should be 
 
 Fig. 239. 
 
 attached to the side of the gold cup into which the porcelain 
 dummy is to be cemented. Figures 238-240 show the three 
 aspects of such a bridge. Ordinarily the attachment would be 
 
 Fig. 240. 
 
 made to the molar and the spud would rest on the bicuspid, but 
 in this instance the attachment is made to the bicuspid and the 
 
THE REPLACING OF LOST TEETH 
 
 289 
 
 spud rests on the molar, as the pulp of the bicuspid had already 
 been destroyed and sufficient anchorage was provided. 
 
 If the bridge is for an upper tooth and the patient is in a 
 great hurry, a gold-backed porcelain facing can be waxed into 
 position on the bar while the abutment is in the mouth, and 
 the whole safely removed, invested, and soldered without the 
 necessity of making a model or an occluding bite. As before 
 stated, the great advantage of this bridge Hes in the fact that, when 
 it is set, floss-silk can be passed under the little spud which is 
 resting on the tooth opposite the attachment, and the whole 
 surface between the gold, dummy, and gum cleansed thoroughly. 
 
 Fig. 241. Fig. 242. 
 
 Figs. 241, 242. — Bridge fastened on both sides for greater rigidity. An opening 
 should be made underneath as shown by circle, through which silk can be passed 
 for purpose of cleansing gum and fixture. 
 
 To accomplish this the contact between the gum and tooth 
 should be curved as Uttle as possible. The dummy and pro- 
 jecting spud can obviously be attached to a gold crown as an 
 abutment if desired. This principle can be applied to a span of 
 one or two teeth, and it can be modified so that the ends may be 
 securely fastened on each side, but this is ordinarily not to be 
 preferred, as such a procedure takes away the individual mobility 
 of each abutment under the stress of mastication. It also makes 
 it necessary that a groove should be made next to the gum for 
 the insertion of floss-silk in order that the daily cleansmg may 
 be accomplished. Figure 241 represents the labial aspect and 
 Fig. 242 the lingual aspect. The circle represents the groove 
 19 
 
290 MODERN DENTISTRY 
 
 made by the passage of a fissure bur along the margin of the 
 gum and the abutment neck. The floss-silk can be threaded 
 through the eye of a blunt needle, and this passed through the 
 opening for the daily cleansing, but it is sometimes advisable 
 to make a flexible needle for this purpose of brass or gold wire 
 (see Fig. 29). Floss-silk can be threaded in the eye of such a 
 needle and be passed under any fixture by the avenue of a 
 properly constructed groove. 
 
 Removable Appliances. — ^When a greater span than two 
 teeth is required the removable clasp bridge is to be preferred, 
 and as this brings us to the final section of the chapter- — the 
 replacement of teeth by clasp fixtures — a short discussion of the 
 subject of gold clasps is appropriate. Wherever clasps are to 
 be made or movable bridge work is to be constructed, it is wise 
 to run the model out in fusible metal. 
 
 A 
 
 Such a metal, composed of 8 parts bis- 
 muth, 5 parts tin, and 3 parts lead, melted 
 and added in the order given, will make 
 a casting that is easy of construction 
 and will withstand hammering and the 
 wear of metal adjustment in a manner 
 Fig. 243.-Correct type of .^ impossible with plaster. When 
 
 clasp for bicuspid or molar. ~i. ir x 
 
 the plaster impression has been taken, 
 it should be dried for a few minutes, then built up with new 
 plaster or moldine to form a cup, and the metal run in at once. 
 A number of these models are shown in figures which follow. 
 
 The clasp should be composed of 20 parts gold, i of platinum, 
 2 of copper, and i of silver. It should be very stiff and springy, 
 that is, it should be sufficiently rigid to withstand the force of mas- 
 tication, and yet sufficiently springy to expand over the inequal- 
 ities of the tooth it clasps and firmly grasp the enamel when it 
 has reached its final position of rest. It should not be less than 
 No. 22 B. and S. gage. Many failures are caused by having the 
 clasp too thin to do its work. The great value of a clasp is in 
 the spud, with which it should always be provided. For instance, 
 in Fig. 243 A represents the clasp and B the spud that rests upon 
 a groove made in the grinding surface of the tooth, so that the 
 
THE REPLACING OF LOST TEETH 29 1 
 
 force of mastication will not cause it to slip up and down under 
 the strain of triturating the food. This spud was apparently 
 first used by Dr. J. D. White some forty years ago, and later 
 was recommended by Dr. Bon will; but the great value of the 
 spud on a clasp does not seem to have been generally grasped, 
 since it is not ordinarily used. A clasp that moves under the 
 stress of mastication cuts and corrodes the enamel. Although 
 
 Fig. 244. — Clasp in position supported Fig. 245. — Tooth worn by clasp where 
 by spud. no spud was used. 
 
 the enamel will soften imder the first action of food fermentation, 
 it hardens again as the food fermentation disappears through 
 proper daily cleansing. If, therefore, the clasp is held immovable 
 by the spud resting on the occlusal surface of the abutment, as in 
 Fig. 244, the partly softened enamel will have a chance to re- 
 harden without wear, but if no spud is used upon the clasp, 
 erosion on the sides of the enamel of the tooth will most surely 
 occur, as in Fig. 245. Thus it is essential that a clasp should 
 
 Fig. 246. — Missing bicuspid to be replaced by a removable bridge with spring 
 
 clasps. 
 
 grasp the tooth firmly and adhere to it firmly under stress of 
 mastication. The simplest form of clasp plate or bridge is shown 
 in Figs. 246-248. Here the sides of the teeth are parallel, and 
 if the clasps are attached to the plate so that they will clasp the 
 largest part of the abutment, the procedure is simple in the ex- 
 treme. But if the two abutments are divergent the method of 
 adjusting the clasp becomes compHcated, and calls for the great- 
 est nicety of adjustment. 
 
292 
 
 MODERN DENTISTRY 
 
 Divergent Abutments. — For instance, in Fig. 249 we have a 
 first bicuspid elongated and divergent from the second molar. 
 Except for the divergence of the axes of the teeth the case is 
 
 \/j/ ^^jL >^(i:Lji^ 
 
 Fig. 247.^ — Gold dummy with gold 
 clasps and spud suitable for filling 
 space in Fig. 246. 
 
 Fig. 248. — Under surface of fixture 
 shown in Fig. 247. 
 
 ideal for a clasp plate. But how to get the two clasps into posi- 
 tion is the problem. The method of overcoming this difficulty 
 is as follows : A plain, broad clasp with a spud attached is fitted 
 
 Fig. 249. — A difficult span to restore on account of divergence of the abutments. 
 
 to the molar, the sides of which should be ground parallel if 
 necessary. A gold plate should be made to fit the gum and a 
 clasp should be adjusted to the Ungual side of the bicuspid, so 
 
 Fig. 250. Fig. 251. 
 
 Figs. 250, 251. — Top and side view of gold clasp that can be slipped on at side of 
 
 the tooth. 
 
 that the sides of the clasp will extend to or just a Httle beyond 
 the greatest bulge of the tooth, and will not extend over the 
 buccal surface at all (Figs. 250, 251). The clasps and plate 
 should then be soldered together in the position they are to occupy 
 
THE REPLACING OF LOST TEETH 
 
 293 
 
 when finished. The details of such a procedure are so well 
 known that it is taken for granted that the reader is acquainted 
 with them. The problem now is to adjust the clasps so that 
 they will be invisible from the outside of the mouth, and yet 
 absolutely rigid when in final position. The bicuspid clasp should 
 be kept lingually free from its tooth, while the molar clasp is 
 slipped all the way down to its place on the molar, and then a 
 simple rotation of the fixture buccally will push the prongs of 
 the bicuspid clasp into position and complete stability will be 
 obtained. In the same way when the fixture is to be removed, 
 the buccal clasp should first be disengaged by pushing it lingually 
 until the jaws of the clasp are entirely free from the tooth, when 
 
 Fig, 252. — Clasp plate being slipped into position where axes of abutments 
 diverge, as shown in Fig, 249. Clasp is slipped well down on molar B while the plate C 
 is slightly rotated inward, then the clasp of the bicuspid A is forced sideways into 
 place, 
 
 it will be a simple matter to slip off the molar clasp from its 
 abutment. See Fig, 252, Of course, if an attempt is made to 
 engage both clasps at once it will be impossible to get the fixti :e 
 into position. 
 
 Figures 253, 254 represent a case in which all of the upper 
 teeth except the canines and bicuspids have been lost. In this 
 case a horseshoe plate carrying all of the missing teeth is fas- 
 tened by clasps to the bicuspids, leaving the hard palate of the 
 mouth uncovered. In the same way two canines or bicuspids 
 can be made to support an entire upper denture. Two clasps 
 properly adjusted to two molars on opposite sides of the mouth 
 can readily support an entire single denture, and at a pinch two 
 molars on the same side can be made to do it, but care must be 
 
294 
 
 MODERN DENTISTRY 
 
 taken to trim the sides of each molar so that they will be parallel 
 and give the maximum support to the fixture, even if the enamel 
 has to be cut through. In such a case the teeth can be capped 
 with gold caps with parallel sides that do not extend beneath the 
 
 Fig. 253. 
 
 Fig. 254. 
 Figs. 253, 254. — Upper denture supported by two canines. 
 
 gum; and if the teeth are sensitive to heat and cold, it is always 
 good practice in any case to destroy the pulp and carefully fill 
 the canals. The following illustrations show some interesting 
 types of fixtures capable of being successfully fastened into posi- 
 
THE REPLACING OF LOST TEETH 295 
 
 tion by clasps. Figure 255 represents the two aspects of a fin- 
 ished plate. Figure 256 shows the gold plate before the teeth 
 
 Fig. 255. — Under and upper view of lower denture supported by two bicuspids 
 
 and a molar. 
 
 are added, and the fusible metal model. Figure 257 represents 
 an interesting illustration of an upper and lower restoration 
 on the right side of the mouth. A represents the fusible metal 
 
 Fig. 256.— Figure on the left represents the gold plate and clasps of Fig. 255 before 
 the teeth are added. On the right is the fusible metal model. 
 
 models on an articulator, B represents the upper fixture, C the 
 lower fixture, D and E represent the gold plates of these fixtures 
 before the teeth are added, F and G represent respectively the 
 
296 
 
 MODERN DENTISTRY 
 
 
 i^^ v' A 
 
 r^. 
 
 ''^~::s^ 
 
 
 D 
 
 y'lj^'^—Xm^. 
 
 Fig. 257. — A, A, Upper and lower fusible metal models; D, E respectively, 
 upper and lower gold fixtures before teeth are added; B, F, two views of finished 
 upper fixture; C, G, lower finished fixture. 
 
THE REPLACING OF LOST TEETH 
 
 297 
 
 gum aspects of the two fixtures when finished. Figure 258 
 represents the lingual aspect of the unfinished plates in position 
 on the model. 
 
 Fig. 258. — Lingual view of plates and models just described. 
 
 Fig. 259. — Upper removable clasp bridge. 
 
 Figures 259-261 represent a removable bridge that is inter- 
 esting on account of the concealed gold clasp on the bicuspid. 
 A is a gold-crowned second molar with parallel sides, B is a 
 
298 MODERN DENTISTRY 
 
 porcelain-faced gold-backed bicuspid. The problem was to 
 make a bridge that would not show the gold clasp at the neck 
 oi B. A broad gold clasp was made for ^ . A pit and groove 
 were made in the grinding surface oi B, as is shown by the dotted 
 
 Fig. 260. — Labial aspect of bridge in position. 
 
 lines (Fig. 260). In Fig. 261 a bent bar and half clasp were 
 adjusted, as is shown by C and D, the attachment to the bicuspid 
 being obtained by grasping the inner cusp between the pin D 
 and the half clasp C. Figures 260 and 261 show the labial and 
 
 Fig. 261.- — Buccal aspect of bridge in position. 
 
 buccal aspects of the bridge in position, while the bridge itself 
 is shown in Fig. 259. 
 
 The Double Clasp Bridge. — There is one type of fixture, 
 however, that deserves special mention, and that is the fixture 
 
THE REPLACING OF LOST TEETH 
 
 299 
 
 that replaces two molars or a molar and bicuspid and is attached 
 on only one side by a double clasp or a clasp and elongation of 
 the plate. A case of special interest is one showing the construc- 
 tion of an all-porcelain bridge attached to the abutment by a 
 double gold clasp and spud (Figs. 262, 263). As observed, the 
 teeth back of the second bicuspid are missing. B represents 
 the gold clasp, No. 22 gage, fitted to the second bicuspid, to the 
 ends of which clasp are added gold projections, C, which half 
 embrace the first bicuspid near the gum hne. A piece of pure 
 gold, No. 35 B. & S., is soldered to the clasp at the posterior 
 aspect of the second bicuspid and burnished into the occlusal 
 groove prepared to receive it. When this is stiffened with half- 
 
 Fig. 262. — Lingual view of all-porcelain bridge with gold clasp in process of con- 
 struction. 
 
 round platinized gold wire and solder it will form the spud A 
 that will prevent the clasp from being driven into the gum by the 
 force of mastication. If the occluding tooth should interfere 
 with the spud, the tooth should be correspondingly shortened. 
 The clasp and spud should now be poUshed to the lines desired, 
 and a thin coating of borax flowed over them so as to expedite 
 future soldering. They should then be placed upon the model and 
 a right-angled piece of No. 14 iridio platinum wire, represented 
 by D, should be adjusted to it at the gum hne. E represents 
 platinum foil, o.ooi inch thick, burnished and trimmed to fit 
 the model. The angle wire, D, should be placed in position 
 on it; continuous gum porcelain body placed on the angle wire; 
 
300 MODEEN DENTISTRY 
 
 and platinum foil and rubber teeth of suitable size and shade 
 placed upon the body, just as in the preparation of the wax model 
 of a rubber case. When the body has been carved to the proper 
 lines of the gum, the platinum foil, angle, bar, teeth, and body 
 should all be removed together, placed in the oven and given 
 a thorough glaze. When the porcelain is cool the platinum foil 
 should be stripped off and new foil burnished to the model. A 
 thin layer of porcelain paste should then be placed on the plati- 
 num foil and the porcelain block pressed and tapped down upon 
 it until the articulation is just a Little high. This extra height 
 is necessary in order that perfect occlusion may be obtained by 
 grinding when the case is finally fitted in the mouth. The ad- 
 ditional porcelain paste is necessary to make up for the contrac- 
 tion caused by the fusing of the porcelain piece in the first bake. 
 
 Fig. 263. — Buccal view of finished all-porcelain bridge with gold clasp for attach- 
 ment. 
 
 When the porcelain has been carved a second time to a satis- 
 factory line, it is removed again on the platinum foil and placed 
 in the oven for another baking. After baking and after the 
 platinum foil is removed, the porcelain block should accurately 
 fit the model. If pink gum enamel is necessary there will have 
 to be a third baking, but for this no platinum foil will be needed 
 to preserve the contour, as the first body fuses at a higher point 
 than the enamel. When the porcelain block is finished, we have 
 a double clasp with a spud and a porcelain block with a platinum 
 bar running through it. It now remains to join them together. 
 The clasp is placed in position on the model; the end of the porce- 
 lain block that goes next to the clasp is ground until the platinum 
 bar is clean and fresh enough to receive the solder. Then to 
 the end of the ground porcelain a thin backing of pure gold 
 should be burnished to make a tight joint with the porcelain, 
 
THE REPLACING OF LOST TEETH 
 
 301 
 
 and held in place with a little hard wax. The middle of this 
 backing should be torn so as to expose the platinum and make it 
 possible to solder together the clasp, gold backing, and platinum 
 bar. The clasp and porcelain should then be placed on the cast 
 and waxed into accurate position. They are then removed, 
 invested, and soldered in the usual way. Figure 263 represents 
 
 Fig. 264 
 
 Fig. 265. 
 
 Fig. 266. 
 Figs. 264-266. — Three aspects of a double clasp bridge with gold plate and vul- 
 canite attachment. 
 
 the finished piece. It might be well to state that varnishing 
 the gum enamel with gum shellac varnish prevents the invest- 
 ment from sticking to it during the process of soldering. 
 
 It is obvious that after the double clasp has been made as 
 just described, instead of using porcelain, a gold plate can be 
 swaged, fitted, and soldered to the clasp. Porcelain teeth can be 
 
302 
 
 MODERN DENTISTRY 
 
 Fig. 267. 
 
 Fig. 268. 
 
 Fig. 269. 
 
 Fig. 270. 
 
 Figs. 267-270. — Double clasp bridge attached to natural teeth on one side only. 
 
 Composed of gold plate and teeth cemented into suitably prepared gold box. 
 
 attached to this plate with vulcanite, as is shown in Figs. 264- 
 266. In this instance the single clasp is used externally and the 
 double support is given on the inside alone. 
 
THE REPLACING OF LOST TEETH 
 
 303 
 
 The All-gold and Porcelain Fixture.— Where it is desired 
 to have teeth cemented into gold so that only the gold and porce- 
 lain will show, the procedure is simple and easy. The plate and 
 clasp should be made as usual and the teeth adjusted and waxed 
 into position (Fig. 267). Then a piece of No. 30 pure gold should 
 be fitted and burnished around the buccal margins of the teeth 
 and plate, as shown in Fig. 268. The teeth and supporting wax 
 
 Fig. 271. 
 
 Fig 272. 
 
 Fig. 273. 
 Figs. 271-273. — Removable gold and porcelain bridge attached to natural 
 teeth on one side only. Teeth are set in gold cups built into position with sponge 
 gold and finally filled full of 22-karat solder. 
 
 are then removed and the burnished gold. A, soldered to the 
 plate. The teeth should then be replaced on the plate and another 
 piece of gold, designated by B, adjusted on the palatal side 
 (Fig. 269). The ends should lap behind the molar. The teeth 
 are once more removed and the gold soldered to form a perfectly 
 fitting gold box (Fig. 270), into which the teeth can be cemented 
 with silicious cement. 
 
304 . MODERN DENTISTRY 
 
 Figures 271-273 show a method of fastening the teeth to the 
 plate by means of gold cups, which gold cups are built up into 
 position by sponge gold, which is later filled full of gold solder. 
 Figure 271 shows the lingual side of the same tj^e of plate with 
 the molar and bicuspid in position. Gold cups made of 0.003 
 inch pure gold have been adjusted to the porcelain as is shown 
 in the illustration. Then a thin film of hard wax is flowed over 
 the base of the gold cups and the adjacent plate, and sponge 
 gold is rapidly and firmly packed in around the teeth and between 
 the teeth and plate (Fig. 272). If necessary a little hard wax 
 can be flowed into the sponge gold to add to its adhesiveness. 
 Then the teeth can be coaxed out of the cups, as shown in Fig. 
 
 Fig. 274. — Interesting type of removable denture composed of gold and porcelain 
 
 only. 
 
 273, and the entire sponge gold mass filled with solder. An 
 investment may be used, but usually it is unnecessary. When 
 the teeth are cemented into the cups the porcelain and gold alone 
 are visible. 
 
 Figures 274-277 represent a completed plate composed of gold 
 and porcelain made on the principle of the gold cup method 
 just described. 
 
 The cases might be multiplied indefinitely, but if the prin- 
 ciples demonstrated are judiciously appHed it will be found that 
 any partial, movable denture can be readily made. 
 
 The method of making full upper and lower dentures sup- 
 ported by suction has not been discussed, as the procedure is 
 
THE REPLACING OF LOST TEETH 
 
 305 
 
 Fig. 275. 
 
 Fig. 276. 
 
 Fig. 277. 
 
3o6 MODERN DENTISTRY 
 
 well known, and success depends largely upon the adaptabiKty 
 of the mouth of the patient. But where a single tooth can be 
 saved to act as a support for what would otherwise be a full upper 
 or lower denture, the efficiency for mastication will ordinarily 
 be increased loo per cent, and the peace of mind of the patient 
 will be assured by the certain knowledge that the plate will not 
 suddenly become dislodged, to his mortification and annoyance. 
 In such a case a well-fitting clasp will prove of invaluable assist- 
 ance. 
 
 The normal tooth matches the undertone of the skin. There- 
 fore, in full dentures where there are no teeth from which to obtain 
 the color, the following expedient may be used: The skin of the 
 patient should be pressed and the color noted before the blood 
 returns to the capillaries. On a cold day this method will be 
 particularly effective. 
 
CHAPTER XI 
 
 EXPERIMENTS CONCERNING THE STRENGTH, SOLU- 
 BILITY, AND ADHESIVENESS OF VARIOUS CEMENTS 
 
 Silicious Cements. — Dr. Ames, the great authority on dental 
 cements, says that "the sihcious cements are really oxyphosphate 
 of calcium, and should be considered as being so compounded 
 that the cement-making phenomenon comes from the action of 
 phosphoric acid on calcium oxid or basic calcium silicate, the 
 action being retarded by the intimate blend with alumina and 
 silica." The action on calcium oxid alone would be very violent. 
 The alumina and silica act as diluents and give integrity to the 
 resulting mass. The formulae of the various cement powders are 
 practically identical with that of calcium feldspar. Feldspar 
 furnishes the chief ingredient of porcelain, and these cements, 
 therefore, may reasonably be considered porcelain in which 
 there is agglutination by chemical action instead of agglutination 
 by heat. 
 
 The term "silicious cement" is more accurately descriptive 
 than the term "silicate cement." Normal silicates do not afford 
 cement-making properties. Sihcious mixtures may. 
 
 Silicious cements will present no difficulties in manipulation 
 if the setting process is considered as being practically that 
 of the oxyphosphates. Mixing cements upon a slab of known 
 temperature has become a habit with a large number of operators. 
 This is accomplished by using the flat side of a bottle containing 
 water of the temperature desired (Fig. 278), which temperature 
 is ascertained ' by a thermometer inserted through the cork. 
 Cold spigot-water ordinarily is sufficient to carry off the heat 
 of the chemical reaction, but for those who wish to make the 
 water colder, almost to the dew point, a wet and dry bulb hydrom- 
 eter is a great convenience. The colder the slab is kept, with- 
 out excess moisture being precipitated from the air, the greater 
 length of time will there be for the manipulation of the cements. 
 
 307 
 
3o8 
 
 MODERN DENTISTRY 
 
 When setting occurs in a judiciously constructed silicious 
 cement the chemical balance is automatically established. As 
 the warmth of the tooth is imparted to the cement, the proper 
 amount of liquid and powder tend to com- 
 bine, and the crystallization begins next 
 to the tooth, continuing toward the center 
 of the mass. If the hquid has been in 
 excess in the mixture it will be left on the 
 surface, and if there has been a shortage 
 of liquid and an excess of powder, the final 
 surface will have a honeycombed appear- 
 ance. For these reasons it is wise to 
 have sufficient liquid to make the surface 
 slightly moist when the cement is being 
 inserted, and any excess moisture may then 
 be finally taken up by an application of 
 powder. Sufficient time should always be 
 allowed for the proper introduction of 
 the cement into the cavity, as the struc- 
 ture of silicious cement is seriously injured 
 if it is manipulated after the process of 
 crystallization has actually begun. 
 
 When the cement is in position and has 
 started to set it is sometimes good practice 
 to flow hot parafiin upon it. This will 
 cause a prompt setting, and will tend to 
 save the time of the operator and prevent 
 the dilution with saliva of the uncombined 
 ingredients. It will also tend to remove any 
 risk of the pulp being injured by the free 
 acid. If such a risk exists, however, it can 
 readily be obviated by lining the cavity 
 with varnish prior to the insertion of the 
 filling. Ordinarily such a precaution is not 
 necessary, but where there is a near approach to the pulp it is 
 always wise to use the cavity hning. In cases where the pulps 
 are supposed to die from the action of the cement, there is always 
 
 Fig. 278. — The Ames 
 cement slab — a flat- 
 sided bottle filled with 
 cold water, on which 
 cement can be mixed. 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 309 
 
 a question whether the pulp died from the action of the cement 
 ingredients, or whether it had not already been fatally attacked 
 by infection before the filling was inserted. 
 
 The adhesion of sihcious cements counteracts a possible 
 tendency toward shrinkage because of the adhesion to the cavity 
 wall. This adhesion, while the cement is soft, will cause a shrink- 
 age toward the wall rather than away from it, since the cement 
 in contact with the cavity wall is the first portion to set because 
 of the heat imparted by the tooth. 
 
 Phosphate of Zinc Cements.— The following experunents 
 were made some years ago with phosphate of zinc cements before 
 the introduction of sihcious cements; and although the sihcious 
 cements by their msolubility have made these tests on the solu- 
 bihty of phosphate cement films of less importance, nevertheless, 
 since phosphate cement is still so universally used for the re- 
 tention of crowns, bridges, and bands, these experiments are 
 reported with the hope that not only the facts brought to hght 
 may prove of value, but also that the technic of the experimen- 
 tation may be of use in aidmg those who would like to extend 
 the scope of these experiments. 
 
 Before the days of sihcious cements the phosphate of zinc 
 cement hne arising from the removal of the matrix was always a 
 subject of general criticism and discussion in porcelain inlay 
 work. By some it was deemed a great advantage to use No. 30 
 gold foil for a matrix. This was so because No. 30 gold foil is 
 one-third the thickness of the o.ooi-inch platmum foil. There- 
 fore, the gold was beheved to make a finished filhng that would 
 leave a cement fine one-third the thickness of the cement line 
 of a filling where the platuium matrix was used. 
 
 These and other statements prompted me to undertake 
 experiments for the purpose of solving the following questions: 
 A. (i) What is the minimum line of cement that can be 
 obtained at the edges of an inlay? (2) Is maintained pressure 
 until the cement sets or fineness of cement grit the more respon- 
 sible for obtaining a fine cement Hne ? (3) Is it of any practical 
 value to maintain pressure for more than a minute while the 
 cement is setting ? 
 
3IO MODERN DENTISTRY 
 
 B. (i) Does a thick or thin line of cement give the greater 
 strength of retention ? (2) Is a fine grit or coarse grit cement 
 the stronger ? 
 
 C. (i) What is the adhesive strength of glazed porcelain 
 cemented to smooth ivory ? (2) What is the adhesive strength 
 of etched porcelain cemented to smooth ivory? (3) What is 
 the adhesive strength of etched porcelain cemented to undercut 
 ivory ? (4) What is the adhesive strength of undercut porcelain 
 cemented to undercut ivory ? 
 
 Tests on Cement Line. — To ascertain the minimum thickness 
 of the cement line pieces -of glass |-inch square were cemented 
 to pieces of glass ^-inch square. These pieces of glass were so 
 true as to permit atmospheric suction when pressed together in 
 a dry state. To facilitate the removal of the cement film the 
 surface was slightly oiled by rubbing on the skin. Pressures 
 of 8, 25, 50, and 100 pounds were used with various grits of the 
 Harvard cement, as well as with Ames' inlay cement, to see 
 whether pressure or fineness of grit was the more responsible 
 for the thin cement line. These pressures in half the number 
 of instances were maintained for a minute only, and the further 
 setting continued without external pressure. With the other 
 half the pressure was maintained until the setting was complete. 
 This was done to see if the maintaining of the pressure for more 
 than one minute was of any practical value in reducing the 
 cement line. The J-inch square film was chosen as a standard 
 cement surface. This is larger than the average surface of a 
 porcelain inlay, but as from 2 to 6 pounds was found from experi- 
 ment to be the pressure ordinarily applied to the average fillings 
 in the mouth, it was considered that definite conclusions could 
 be obtained from 8, 25, 50, and 100 pounds pressure applied to 
 films ^-inch square, and that these films would be large enough 
 to measure at several points and give an average thickness. The 
 measurements for thickness were made with the Black amalgam 
 micrometer, and those for pressure with the Black dynamometer. 
 
 All of the cement films were allowed to set in a dry state, 
 and it was found that when they were dipped in water the glass 
 pieces separated and the complete film was easily dislodged and 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 3II 
 
 floated off. It was then picked up on a camel's-hair brush and 
 attached to the face plate of the micrometer, when the various 
 readings were obtained by moving the film of cement on the face 
 plate under the measuring terminal. The film of water between 
 the cement film and the face plate was found to be o.oooi inch 
 in thickness in the following way: A reading was taken while 
 the wet film of cement was still adherent to one of the glass 
 pieces. The cement film was then loosened so that a film of 
 water could creep underneath and the reading again taken. 
 By numerous such tests the water fihn was found to be o.oooi 
 inch. Thus o.oooi inch will be deducted from every reading 
 given in the tables of film measurements unless otherwise 
 stated. The readings of the Black amalgam micrometer were 
 controUed by the Brown & Sharpe micrometer, and while 
 the Brown & Sharpe micrometer could not measure quite so 
 minutely as the Black, in so far as they could be compared, the 
 measurements for both instruments were the same. The pres- 
 sure generaUy used in cementing fillings in the mouth was arrived 
 at in the following manner: Porcelain inlays having a surface 
 about i-inch square were made to fit cavities in a block of ivory. 
 This block was then placed on scales and the fiUings cemented 
 into position. Without looking at the dial, pressures were used 
 such as were felt to be ordinarily used in the mouth, while an 
 assistant noted the readings. It was found that 2 pounds was 
 the pressure used where there were frail edges, 3 to 4 pounds 
 were safely appUed to ordinary filHngs, and 6 pounds seemed 
 the maximum pressure that would ordinarily be appHed to a 
 filHng with a surface |-mch square. This equals i pound for 
 frail filHngs of i^-inch square surface. These measurements 
 on the force usually apphed in the mouth make the tests of 8 
 and 25 pounds pressure the only ones of practical working value, 
 but, as previously stated, films of cement were also made under 
 50 and 100 pounds pressure to determine the minimum cement 
 line, and to determine whether the pressure under which the 
 cement was set or the fineness of the grit was the more re- 
 sponsible for the minimum fine. 
 
 Of the Harvard cement four different grits were used: (i) 
 
312 MODERN DENTISTRY 
 
 Harvard coarse, such as was ordinarily used for making fillings 
 and such as was for a long time ordinarily used for cementing 
 inlays. (2) Harvard inlay cement, as prepared for Dr. Jenkins. 
 (3) A finer grit Harvard which I had especially prepared and 
 used up to the time of these tests. This I shall speak of as the 
 Harvard special. (4) A Harvard cement pulverized in an agate 
 mortar until the grit was almost imperceptible to the teeth, and 
 which will be referred to as Harvard pulverized. 
 
 No use was made of a reduced grit of the Ames inlay cement, 
 as it was found that any reduction of the powder so hastened 
 the setting as to render it unavailable. 
 
 Using 8 pounds pressure for one minute the average thickness 
 of the cement was found to be as follows : 
 
 Harvard coarse 0024 inch 
 
 Harvard inlay 0017 " 
 
 Harvard special 0015 " 
 
 Harvard pulverized 0003 " 
 
 Ames inlay 0010 " 
 
 (See Tables 1-6, 13-15.) 
 
 The tests of 25, 50, and 100 pounds pressure were made 
 only on the Harvard special and the Ames inlay cement. (See 
 Tables 7 to 12, 16 to 21.) These were only of interest in showing 
 that there was an inverse ratio between the pressure and the 
 cement line. In other words, the greater the pressure, the finer 
 the Hne obtained. The Harvard special at 100 pounds gave a 
 line 0.0009 iiich in thickness and the Ames at 100 pounds gave 
 a line 0.0006 inch in thickness, while the Harvard pulverized 
 at but 8 pounds gave a line less than 0.0003 inch. Therefore 
 it seems that a finer grit is a much more important factor than 
 pressure in obtaining a fine hne. 
 
 Maintaining the pressure until setting was complete instead 
 of maintaining it for one minute, was found to result in a differ- 
 ence of only 0.00005 inch, a difference less than the probable 
 working error of the operator. The result was obtained by taking 
 the general average of all the films made under maintained pres- 
 sure and comparing it with the general average of all the films 
 set under a pressure for one minute only. However, though this 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 
 
 313 
 
 is of little importance in reducing the cement line, it is possible 
 that it is of great importance in increasing the adhesion. This 
 will be discussed later. 
 
 In preparing each of the following tables five and occasionally 
 six or seven measurements were taken on each of five similar 
 films. 
 
 TABLE I.— HARVARD COARSE W. 
 
 Harvard coarse W = Harvard coarse grit, pressure 8 pounds on one-quarter 
 inch square glass for i minute. 
 
 Water film that floated cement on face plate measured o.oooi inch. Therefore, 
 o.oooi inch should be subtracted from each result as an error due to measuring the 
 water film with the cement film. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .00275 
 
 .0026 
 
 •00255 
 
 .0027 
 
 .00265 
 
 = 
 
 .00250 
 
 ,00245 
 
 .00265 
 
 .00270 
 
 .00250 
 
 .00260 
 
 = 
 
 .00258 
 
 .00242 
 
 .00215 
 
 .00225 
 
 .00250 
 
 .00236 
 
 = 
 
 .002526 
 
 ,00242 
 
 .00260 
 
 .00280 
 
 .00265 
 
 .00265 
 
 = 
 
 .002624 
 
 ,00220 
 
 .00266 
 
 .00230 
 
 .00220 
 
 .00225 
 
 = 
 
 .002442 
 
 General average, .002534 inch. 
 Corrected average, .002434 inch. 
 
 TABLE 2.— HARVARD COARSE W 
 
 Harvard coarse W' same as Harvard coarse W except that pressure is main- 
 tained until setting is complete. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .00260 
 
 .00285 
 
 .00270 
 
 .00270 
 
 .00260 
 
 = 
 
 .00269 
 
 .00230 
 
 .00235 
 
 .00225 
 
 .00215 
 
 .00215 
 
 = 
 
 .00226 
 
 .00280 
 
 .00272 
 
 .00250 
 
 .00276 
 
 .00284 
 
 = 
 
 .002724 
 
 .00290 
 
 .00300 
 
 .00284 
 
 .00294 
 
 .00290 
 
 = 
 
 .002901 
 
 .00250 
 
 .00250 
 
 .00250 
 
 .00245 
 
 .00245 
 
 = 
 
 .002408 
 
 General average, .002596 inch. 
 Corrected average, .002496 inch. 
 
 TABLE 3.— HARVARD INLAY W 
 
 Harvard inlay W = Harvard inlay cement, one-quarter inch square glass, 
 8 pounds pressure for i minute and then released until setting occurs. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .00175 
 
 .00180 
 
 .00180 
 
 .00185 
 
 .00180 
 
 = 
 
 .0018 
 
 .00165 
 
 .00182 
 
 .00186 
 
 .00186 
 
 .00165 
 
 = 
 
 .00179 
 
 .00180 
 
 .00175 
 
 .00165 
 
 .00176 
 
 .00180 
 
 = 
 
 .00173 
 
 .00170 
 
 .00180 
 
 .00192 
 
 .00185 
 
 .00180 
 
 = 
 
 .00181 
 
 .00178 
 
 .00185 
 
 .00184 
 
 .00175 
 
 .00175 
 
 = 
 
 .00179 
 
 General average, .00178 inch. 
 Corrected average, .00168 inch. 
 
314 MODERN DENTISTRY 
 
 TABLE 4.— HARVARD INLAY W 
 
 Harvard inlay W' = Harvard inlay W, 8 pounds pressure maintained until 
 complete setting occurs. 
 
 Water film that floated cement on face plate measured o.oooi inch. Therefore, 
 o.oooi inch should be subtracted from each result as an error due to measuring 
 the water film with the cement film. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .00180 
 
 .00170 
 
 .00160 
 
 .00175 
 
 .00170 
 
 = 
 
 .00171 
 
 .00175 
 
 .00188 
 
 .00175 
 
 .00175 
 
 .00175 
 
 = 
 
 .00177 
 
 .00185 
 
 .00195 
 
 .00190 
 
 .00195 
 
 .00190 
 
 = 
 
 .00195 
 
 .00205 
 
 .00172 
 
 .00195 
 
 .00185 
 
 .00195 
 
 = 
 
 .00194 
 
 .00165 
 
 .00170 
 
 .00175 
 
 .00170 
 
 .00160 
 
 = 
 
 .00168 
 
 General average, .00181 inch. 
 Corrected average, .00171 inch. 
 
 TABLE 5.— HARVARD SPECIAL W 
 
 Harvard Special = Harvard cement especially prepared for Dr. Head and 
 used by him before these tests were undertaken. 
 
 Harvard Special W = Harvard special, one-quarter inch glass, 8 pounds pressure 
 for I minute and released = one-eighth inch glass under 2 pounds pressure. 
 
 Water film that floated cement on face plate measured 0.0001 inch. There- 
 fore, O.OOOI inch should be subtracted from each result as an error due to measur- 
 ing the water film with the cement fihn. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Average 
 
 .0015 
 
 .00145 
 
 •00155 
 
 •00155 
 
 •00155 
 
 = .00152 
 
 .0017 
 
 .0018 
 
 .0019 
 
 .0017 
 
 .0019 
 
 = .0018 
 
 .00195 
 
 .0015 
 
 .0018 
 
 .0017 
 
 .00195 
 
 = .00176 
 
 .00155 
 
 .00155 
 
 .00165 
 
 .00165 
 
 .0016 
 
 = .0016 
 
 .0015 
 
 •00155 
 
 .0016 
 
 .0017 
 
 .0018 
 
 = .00163 
 
 General average, .00166. 
 Corrected average, .00156 inch. 
 
 TABLE 6.— HARVARD SPECIAL W' 
 
 Harvard Special W' = same as Harvard Special W, only pressure is continued 
 for 15 minutes or until set. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 •0015 
 
 .0016 
 
 .0015 
 
 .0017 
 
 .00175 
 
 = 
 
 .00161 
 
 .00145 
 
 .0015 
 
 .00165 
 
 .0016 
 
 .00145 
 
 = 
 
 .00153 
 
 .00195 
 
 .00175 
 
 .0018 
 
 .0017 
 
 .00195 
 
 = 
 
 .00171 
 
 .00145 
 
 .00155 
 
 .0016 
 
 .00175 
 
 .0018 
 
 = 
 
 .00163 
 
 .0016 
 
 .0018 
 
 .0017 
 
 .00145 
 
 00165 
 
 = 
 
 .00164 
 
 General Average, .00162 inch. 
 Corrected average, .00152 inch. 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 
 
 315 
 
 TABLE 7.— HARVARD SPECIAL X 
 
 Harvard Special X = Harvard special, 25 pounds pressure for i minute and 
 released. 
 
 Water film that floated cement on face plate measured o.oooi inch. Therefore, 
 o.oooi inch should be subtracted from each result as an error due to measuring 
 the water film with the cement film. 
 
 Inch 
 
 •00155 
 
 .00148 
 
 .00160 
 
 .00164 
 
 .00162 
 
 Inch 
 
 Inch 
 
 Inch 
 
 .00145 
 
 .00155 
 
 •00155 
 
 •0015s 
 
 .00142 
 
 .00145 
 
 .00145 
 
 .00130 
 
 .00148 
 
 .00160 
 
 .00152 
 
 .00144 
 
 .00150 
 
 .00172 
 
 .00161 
 
 Inch 
 
 
 Average 
 
 
 = 
 
 .00152 
 
 .00134 
 
 = 
 
 •00155 
 
 .00145 
 
 = 
 
 •00145 
 
 .00155 
 
 = 
 
 •00155 
 
 .00152 
 
 = 
 
 •00159 
 
 General average, .00153 inch. 
 
 Corrected average, .00143 inch. 
 
 TABLE 8.— HARVARD SPECIAL X' 
 
 Harvard special X' = Harvard special, 25 pounds pressure until set, or about 
 30 minutes. 
 
 Inch 
 .0016 
 .00120 
 .00125 
 .00130 
 .00110 
 
 Inch 
 
 Inch 
 
 Inch 
 
 .0016 
 
 .00135 
 
 .0013 
 
 .00125 
 
 .00115 
 
 .00120 
 
 .00132 
 
 .00125 
 
 .00134 
 
 .00132 
 
 .00132 
 
 .00125 
 
 .00110 
 
 .00122 
 
 .00110 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .0013 
 
 .0014 
 
 = 
 
 .00145 
 
 .00135 
 
 
 = 
 
 .00145 
 
 .00130 
 
 
 = 
 
 .00129 
 
 .00130 
 
 
 = 
 
 .00130 
 
 .00108 
 
 
 = 
 
 .00129 
 
 General average, .00135 inch. 
 
 Corrected average, .00125 inch. 
 
 TABLE 9.— HARVARD SPECIAL Y 
 
 Harvard special Y = Harvard special, under 50 pounds pressure, one-quarter 
 inch glass, i minute and then released. 
 
 Inch Inch Inch Inch Inch Average 
 
 .00125 = .00129 
 
 .00098 .00080 = .000976 
 
 .00135 .00135 = .00136 
 
 .00100 .00085 ~ .00094 
 
 .00135 .00135 = .00124 
 
 .00120 
 
 .00125 
 
 .00145 
 
 .00105 
 
 .00120 
 
 .00085 
 
 .00120 
 
 .00145 
 
 .00145 
 
 .00090 
 
 .00100 
 
 .00095 
 
 .00160 
 
 .00140 
 
 .00150 
 
 General average, .00116 inch. 
 
 Corrected average, .00106 inch. 
 
 TABLE 10.— HARVARD SPECIAL Y' 
 
 Harvard special Y' = Harvard special, under 50 pounds pressure, one-quarter 
 inch glass, until set. 
 
 Inch 
 .00125 
 .00135 
 .00130 
 •oono 
 .00135 
 
 Inch 
 .0015 
 .00140 
 .00115 
 .00115 
 .00110 
 
 Inch 
 .00125 
 .00130 
 .00120 
 •00135 
 .00125 
 
 Inch 
 .0013 
 .00160 
 
 .00140 
 .00110 
 
 Inch 
 .0015 
 .00150 
 
 •00135 
 .00100 
 
 Inch 
 .00135 
 
 .00105 
 
 Inch 
 .0015 
 
 Average 
 .00133 
 .00143 
 .00122 
 .001235 
 .00116 
 
 General average, .001275 inch. Corrected average, .001 175' inch. 
 
3l6 MODERN DENTISTRY 
 
 . TABLE II.— HARVARD SPECIAL Z 
 
 Harvard special Z = Harvard special, under loo pounds pressure, one-quarter 
 inch glass, i minute, released. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Average 
 
 .00140 
 
 .00125 
 
 •00155 
 
 .00120 
 
 .00150 
 
 = .00138 
 
 .00120 
 
 .00125 
 
 .00125 
 
 .00110 
 
 .00125 ' 
 
 = .00121 
 
 .00110 
 
 .00115 
 
 .00095 
 
 .00120 
 
 .00120 
 
 = .00112 
 
 .00110 
 
 .00110 
 
 .00125 
 
 .00130 
 
 .00120 
 
 = .00121 
 
 ,00130 
 
 .00120 
 
 .00130 
 
 ■00135 
 
 .00125 
 
 = .00128 
 
 General average, .00124 inch. Corrected average, .00114 inch. 
 
 TABLE 12.— HARVARD SPECIAL Z' 
 Harvard special Z' = Harvard special, 100 pounds pressure until set, one- 
 quarter inch glass. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .00095 
 
 .00100 
 
 .00125 
 
 .00100 
 
 .00095 
 
 .001 
 
 = 
 
 .00102 
 
 .00085 
 
 .00100 
 
 .00070 
 
 .00090 
 
 .00115 
 
 
 = 
 
 .00092 
 
 .00110 
 
 .00110 
 
 .00098 
 
 .00105 
 
 .00080 
 
 
 = 
 
 .00101 
 
 .00110 
 
 .00085 
 
 .00100 
 
 .00105 
 
 .0090 
 
 
 = 
 
 .00098 
 
 .00110 
 
 .0090 
 
 .00100 
 
 .00105 
 
 .0090 
 
 .00110 
 
 = 
 
 .00101 
 
 Inch 
 
 Inch 
 
 .00015 
 
 .0003 
 
 .00035 
 
 .00025 
 
 .0003 
 
 .00025 
 
 General average, .00099 inch. Corrected average, .00089 inch. 
 
 TABLE 13.— HARVARD PULVERIZED W 
 
 Harvard pulverized W = Harvard pulverized cement, pressure of 8 pounds 
 maintained until setting occurred. Factor of error due to water film not present, 
 as the measurements were made on adhesive films, the cement film being too thin 
 to be removed. 
 
 Inch Inch Inch 
 
 .00015 .0002 .00035 
 
 .0002 -00035 .0003 
 
 .00025 .0003 .0003 
 
 General average, .00027 inch. 
 
 Tests of the Ames inlay cement to determine the thickness of 
 the film under given surfaces, times, and pressures were as follows : 
 
 TABLE 14.— A-W 
 
 Ames— W = one-quarter inch square glass at 8 pounds pressure for i minute ; 
 one-eighth inch square glass at 2 pounds for i minute. 
 
 Water fihn that floated cement on face plate measured o.oooi inch. Tehrefore, 
 o.oooi inch should be subtracted from each result as an error due to measuring the 
 water film with the cement film. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .00105 
 
 .0011 
 
 .00105 
 
 .0012 
 
 .001 
 
 .00105 
 
 
 = 
 
 
 .00107 
 
 .0014 
 
 .0012 
 
 .00115 
 
 .0013 
 
 .0015 
 
 .0011 
 
 .00125 
 
 = 
 
 
 .00127 
 
 .0012 
 
 .0012 
 
 .00115 
 
 .0013 
 
 .0012 
 
 
 
 = 
 
 
 .00121 
 
 .00115 
 
 .0012 
 
 .00115 
 
 .00105 
 
 .00105 
 
 
 
 = 
 
 
 .00112 
 
 .0012 
 
 .00125 
 
 .0015 
 
 .0013 
 
 .0012 
 
 
 
 = 
 
 
 .00129 
 
 
 General average, .00119 
 
 inch. 
 
 Corrected average 
 
 , .00109 
 
 inch. 
 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 
 
 317 
 
 TABLE 15— A-W 
 Ames-W = one-quarter inch square glass at 8 pounds pressure for 15 minutes 
 or until complete setting = one-eighth inch square glass at 2 pounds for 15 minutes 
 or until set. 
 
 Inch Inch Inch Inch Inch Inch Average 
 
 .001 .00095 -ooi -ooi .00105 -ooi = -ooi 
 
 .001 .0011 .00105 -ooi .00105 = .001 + 
 
 .001 .001 .0011 .0012 .0012 = .0011 
 
 .00105 .00105 .0011 .0011 .00112 = .ooii-|- 
 
 .00112 .00112 .00112 .00112 .00112 = .00112 
 
 General average, .00106 inch. 
 Corrected average, .00096 inch. 
 
 TABLE 16.— A-X 
 Ames-X = one-quarter inch square glass, 25 pounds pressure for i minute 
 released, and allowed to harden. 
 
 Inch 
 .001 
 .00095 
 .00095 
 .0011 
 .001 
 
 General average, .000986 inch. 
 Corrected average, .000886 inch. 
 
 TABLE 17.— A-X' 
 Ames-X' = one-quarter inch square glass, 25 pounds continuous pressure 
 until hard. 
 
 Inch Inch Inch Inch 
 
 .00085 .0009 .0009 .0009 
 
 .00085 .0009 .00105 .0011 
 
 .0012 .001 .0014 .0012 
 
 .00095 .00082 .001 .0011 
 
 .0009 .001 .0009 .0011 
 
 General average, .000982 inch. 
 Corrected average, .000882 inch. 
 
 TABLE 18.— A-Y 
 Ames— Y = one-quarter inch square glass, 50 pounds pressure for i minute, 
 released, and allowed to harden. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 .001 
 
 .001 
 
 .001 -|- 
 
 .00105 
 
 .0085 
 
 .0009 
 
 .00095 
 
 .001 
 
 .0011 
 
 .00085 
 
 .0009 
 
 .00105 
 
 .00095 
 
 .001 
 
 .00105 
 
 Inch 
 
 
 Average 
 
 .00105 
 
 = 
 
 .00101 
 
 .001 
 
 = 
 
 .00095 
 
 .001 
 
 = 
 
 .001 
 
 .001 
 
 = 
 
 .00098 
 
 .00095 
 
 = 
 
 .00099 
 
 Inch 
 
 Inch 
 
 Average 
 
 .0009 
 
 
 = .00089 
 
 .001 
 
 
 = .00098 
 
 00095 
 
 .00103 
 
 = .00113 
 
 .00085 
 
 
 = .00094 
 
 .00095 
 
 
 = .00097 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Average 
 
 .00075 
 
 .0008 
 
 .00085 
 
 .00075 
 
 .00085 
 
 = .0008 
 
 .0008 
 
 .00095 
 
 .00085 
 
 .00085 
 
 .0009 
 
 = .00085 
 
 .0009 
 
 .00085 
 
 .0008 
 
 .00088 
 
 .00085 
 
 = .000856 
 
 .0008 
 
 .0008 
 
 .0009 
 
 .00095 
 
 .00085 
 
 = .00086 
 
 .00065 
 
 .00075 
 
 .0008 
 
 .00075 
 
 .00085 
 
 = .00076 
 
 General average, .000825 inch. 
 Corrected average, .000725 inch. 
 
3i8 
 
 MODERN DENTISTRY 
 
 TABLE 19.— A-Y' 
 
 Ames-Y' = one-quarter inch square glass, 50 pounds continuous pressure 
 
 until hard. 
 
 
 
 
 
 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .0008 
 
 .00075 
 
 .00082 
 
 .00082 
 
 .00085 
 
 = 
 
 .000808 
 
 .0008 
 
 .00075 
 
 .00077 
 
 .00072 
 
 .00069 
 
 = 
 
 .000746 
 
 .00095 
 
 .00085 
 
 .0007 
 
 .0008 
 
 .0008 
 
 = 
 
 .00082 
 
 .001 
 
 .00085 
 
 .00075 
 
 .00085 
 
 .001 
 
 = 
 
 .00089 
 
 .0007 
 
 .00085 
 
 .0007 
 
 .0008 
 
 .0007 
 
 = 
 
 .00075 
 
 General average, .000802 inch. 
 Corrected average, .000702 inch. 
 
 
 
 TABLE 20.—. 
 
 \-Z 
 
 
 
 Ames-Z = 
 
 one-quarter 
 
 inch square glass, 
 
 100 pounds 
 
 pressure for i minute, 
 
 released, and allowed to harden. 
 
 
 
 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .00085 
 
 .00085 
 
 .00095 
 
 .0009 
 
 .00005 
 
 = 
 
 .00093 
 
 .00085 
 
 .0007 
 
 .00095 
 
 .0007 
 
 .00075 
 
 = 
 
 .00079 
 
 .00095 
 
 .00085 
 
 .0007 
 
 .0008 
 
 .0008 
 
 = 
 
 .00082 
 
 .001 
 
 .00085 
 
 .00075 
 
 .00085 
 
 .001 
 
 = 
 
 .00089 
 
 .0011 
 
 .001 
 
 .00095 
 
 .00095 
 
 .0011 
 
 = 
 
 .00102 
 
 General average, .00089 inch. 
 Corrected average, .00079 inch. 
 
 TABLE 21.— A-Z' 
 
 Ames-Z' = one-quarter inch square glass, 100 pounds pressure until hard. 
 
 Inch Inch Inch Inch 
 
 .0008 .00082 .00075 .0007 
 
 .00065 .00075 .0007 .0006 
 
 .00075 .00065 .0008 .0007 
 
 .00061 .00073 .00061 .0006 
 .0006 .00065 .00065 .00085 
 
 General average, .000704 inch. 
 Corrected average, .000604 inch. 
 
 Inch 
 
 Inch 
 
 Average 
 
 .0008 
 
 .0007 
 
 = .00076 
 
 .0008 
 
 .00085 
 
 = .000725 
 
 .00065 
 
 
 = .00071 
 
 .00062 
 
 
 = .000634 
 
 .00075 
 
 
 = .00007 
 
 TABLE 22.— ASH W 
 
 Ash W = Ash common phosphate of zinc cement, 8 pounds pressure, one- 
 quarter inch square glass, for i minute, and released. 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 Inch 
 
 
 Average 
 
 .0021 
 
 .00215 
 
 .00195 
 
 .00195 
 
 .00212 
 
 = 
 
 .00206 
 
 .0022 
 
 .0023 
 
 .0024 
 
 .00233 
 
 .00235 
 
 = 
 
 .00230 
 
 .00231 
 
 .00230 
 
 .00230 
 
 .00230 
 
 .00230 
 
 = 
 
 .00230 
 
 .00215 
 
 .0029 
 
 .00265 
 
 .00210 
 
 .00220 
 
 = 
 
 .0024 
 
 .00280 
 
 .0029 
 
 .00290 
 
 .00310 
 
 .00280 
 
 = 
 
 .0029 
 
 General average, .00239 inch. 
 Corrected average, .00229 inch. 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 
 
 319 
 
 Comparisons are given of corrected general averages of cement 
 lines made under 8 pounds pressure. W = released after i 
 minute. W = pressure maintained until setting is complete. 
 Except in Harvard pulverized, which was measured adhering to 
 glass, o.oooi inch was subtracted from each as a factor of error. 
 
 Harvard coarse W 00243 i^^ch 
 
 Harvard coarse W 00249 inch 
 
 Harvard inlay W 00168 inch 
 
 Harvard inlay W 00171 inch 
 
 Harvard special W 00156 inch 
 
 Harvard special W 00152 inch 
 
 Harvard pulverized 00027 i^^ch 
 
 Ash W .00229 iiich 
 
 Ames-W 00109 i^ch 
 
 Ames-W 00096 inch 
 
 X = 25 pounds pressure one-quarter inch square glass for i 
 minute, then released. 
 
 X' = 25 pounds pressure one-quarter inch square glass until 
 complete setting occurs. 
 
 Y = 50 pounds pressure one-quarter inch square glass for 
 I minute, then released. 
 
 Y' = 50 pounds pressure one-quarter inch square glass until 
 setting occurs. 
 
 Z = 100 pounds pressure one-quarter inch square glass for 
 I minute, then released. 
 
 Z' = 100 pounds pressure one-quarter inch square glass 
 until setting occurs. 
 
 H = Dr. Head's special Harvard. 
 A = Ames Inlay Cement. 
 
 Comparison of corrected general averages between the Har- 
 vard special and the Ames cements : 
 
 H X = .00143 inch 
 
 AX = 
 
 .000886 inch 
 
 HX' = .00125 " 
 
 AX' = 
 
 .000882 " 
 
 HY = .00106 " 
 
 AY = 
 
 .000725 " 
 
 HY' = .00118 " 
 
 AY' = 
 
 .000702 " 
 
 HZ = .00114 " 
 
 AZ = 
 
 .00079 " 
 
 HZ' = .00089 " 
 
 AZ' = 
 
 .000604 " 
 
320 
 
 MODERN DENTISTRY 
 
 Having discussed the fineness of cement lines and having 
 arrived at the conclusion that the fine cement line is due to the 
 fineness of the cement powder, rather than to the amount of pres- 
 sure applied or to the length of time the pressure is maintained, 
 let us take up the question of strength and adhesion. As before 
 stated, the Harvard cements and the Ames' inlay cement were 
 the only ones investigated at length. Of Harvard, the coarse 
 and the pulverized were used as two extremes to show which gave 
 the most strength and the greatest adhesion. 
 
 Adhesion of Cement. — The first adhesion tests were made 
 with the glass squares etched with hydrofluoric acid. Pieces 
 j-inch square were cemented to pieces |-inch square under 8 
 pounds pressure for fifteen minutes, and set in water over night. 
 Two specimens of Harvard coarse, three of Harvard pulverized, 
 and two of the Ames inlay were thus prepared. In the morning 
 the glasses all fell apart. This result showed that the expansion 
 and contraction of the glass was sufficient to tear it loose from 
 the cement. At first it was thought the tests would have to be 
 made in a culture oven at a temperature of 98° F., the normal 
 temperature of the mouth ; but tests with a cHnical thermometer 
 in the mouth after eating hot soup at 152° F. showed that the 
 mouth could by this means be raised to a temperature of 108° F. 
 This demonstrated that experiments made in an even temperature 
 would not be fair, as it was apparent that a filling might be sub- 
 jected to hot soup at a temperature of 152° F. and ice cream at a 
 temperature of 32° F., a variation of 120 degrees. Therefore, for 
 the adhesion tests glass was discarded and pieces of porcelain 
 |-inch square and rS'-inch thick, perfectly flat, were cemented to 
 a block of ivory that had been draw-filed flat and smooth. In all 
 of these tests the porcelain and ivory were washed with alcohol 
 and dried before they were cemented together. In the tests 
 where the porcelain was only ground with a wheel the results 
 were so discouraging that they will only be summarized. The 
 porcelain pieces were carefully ground so as to be the same size 
 in order that a just comparison could be obtained. 
 
 A number of tests were made under 8 pounds pressure and 
 thumb pressure until setting was complete, and some under 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 32 1 
 
 thumb pressure for a minute, and then released. The Harvard 
 cement was paraffined before being placed in water. The Ames 
 cement was not paraffined, as the Ames cement set better when 
 exposed to water. The following morning the pieces of ivory 
 and porcelain were removed from the water, dried with a cloth, 
 and the paraffin and cement carefully cleansed from the edges. 
 The ivory block was then placed in a vise and the pieces of porce- 
 lain pulled off sideways with the hook of a spring balance scale. 
 Before each test the face of the scale was blackened in a gas jet 
 so that the indicator would mark the highest mark reached as 
 the cement broke and the pointer flew back. These same spring 
 scales were arranged with nails and board so that they could be 
 used to maintain the required pressure on the cement films as 
 they were setting. The results were so insignificant, there being 
 practically no difference between the maintained pressure, the 
 temporary pressure, the 8 pounds pressure, and the 4 pounds 
 or thumb pressure, that for the plain, ground porcelain surfaces 
 only those made under thumb pressure, released after one minute, 
 and then set in water over night will be quoted. The tests made 
 with the Harvard coarse gave a breaking strain of the following 
 figures: 3, 5, 14, 19, 21, 13, 27, 28, 34, 42 ounces — an average 
 of 20 ounces. Harvard pulverized gave the following figures: 
 10, 10, 16, 8, 31, 35, II, 16, 54, 32 ounces— an average of 22 
 ounces. The Ames cement under similar conditions gave: 
 o, o, 64, 20, 10, 6, o, o, 10, 32 ounces — an average of 14 ounces. 
 These roughly show a slight superiority of adhesion for the 
 pulverized Harvard, but the result is not sufficiently conclusive 
 to be of great value. It certainly shows that the adhesion of 
 cement to ground porcelain and to flat, smooth ivory is slight 
 and unreliable. In these tests the cement film seemed to break 
 away equally from the porcelain and ivory. 
 
 Having proved that draw-filed ivory and ground porcelain 
 have very little adhesion to cement, the pieces of porcelain were 
 etched for thirty seconds with hydrofluoric acid, washed thor- 
 oughly with water, dried, washed in alcohol, and dried again. 
 The blocks of ivory were simply given the ordinary soaking in 
 water to make them as much like the tooth structure as possible, 
 
322 MODERN DENTISTRY 
 
 wiped dry with a cloth, the surfaces washed with alcohol, and 
 dried with the air-blast. Because the etching with hydrofluoric 
 acid had caused so little adhesion of the cement to the glass, 
 I had doubts as to whether it would cause adhesion to a flat 
 surface of porcelain. Roughening the surface of a deep porce- 
 lain filling would obviously act as small undercuts and cause 
 the cement to retain the filling, but there was much doubt in 
 my mind concerning the power of etching to cause adhesion 
 of cement to a flat surface. 
 
 Six preliminary tests were made with the ^-inch square of 
 etched porcelain cemented to the ivory blocks under 8 pounds 
 pressure for one minute and then released, two with Harvard 
 coarse, two with Harvard pulverized, and two with the Ames 
 inlay. Next morning the four Harvard cement films tore away 
 from the ivory at about a 67-ounce pull, remaining firmly ad- 
 herent to the porcelain, while the Ames cement dropped off the 
 ivory with a pull too small to be measured. This seemed to give 
 a maximum adhesion of the Harvard cement to a plain ivory 
 |-inch square of a little over 4 pounds. 
 
 It was then seen that if the adhesion of cement to etched 
 porcelain was to be measured, some way would have to be 
 devised to make the cement stick more securely to the ivory. 
 This was done by making deep undercuts in the ivory. These 
 undercuts were filled with the cement and the pieces of etched 
 porcelain pressed upon the overflowing cement, kept under 8 
 pounds pressure for one minute, and then released and treated 
 in the usual way. Next morning, when these pieces of porcelain 
 were pulled off, the two etched squares of porcelain broke loose 
 from the Harvard coarse cement at 16 pounds and 22 pounds 
 each. The Ames broke at 6 pounds and 3 pounds each. In 
 each test there was clean tearing away of the porcelain from the 
 cement. The next tests were identical with those just described, 
 only the old cement in the undercuts was simply filed smooth, 
 and the cleansed porcelain squares cemented under 8 pounds 
 pressure for one minute to the old cement and the adjacent 
 ivory that had simply been washed with alcohol and dried. 
 Further tests proved that the fresh cement would stick to 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 
 
 323 
 
 the old cement more firmly than it would stick to the etched 
 porcelain. 
 
 The following tables and their general averages tell their 
 own story. Tests, as previously stated, were made under 8 
 pounds pres.ure for one minute. These same tests were dupli- 
 cated with the 8 pounds pressure maintained until setting was 
 complete. Harvard coarse, under 8 pounds pressure for one 
 minute, released, paraffined, set in water over night and pulled 
 off in the morning, showed that etched porcelain broke away 
 from undercut ivoiy at 16, 22, 16, 12, 11, 13, 15, 20, 16, 11, 12, 
 14, 14, i4> 16, 12, 15, 10 pounds. General average 13 pounds, 
 2 ounces, to i-inch square surface. When the pressure was 
 maintained until setting cccurred, the breaking strain was 
 found to give the following figures: 6, 16, 13, 10, 12, 18, 13, 4, 
 10, 8, 9 pounds, giving a general average of 11 pounds, 10 ounces. 
 This shows that with Harvard coarse maintaining the pressure 
 did not increase the adhesion. These same tests were made 
 with Harvard pulverized. Where the 8 pound pressure was 
 maintained for one mmute only, we have the following figures: 
 12, 12, 13, 8, 9, 13, 18, 21 pounds, giving a general average of 
 13 pounds, 4 ounces. Where pressure was maintained until 
 setting was complete, the following were the figures: 16, 12, 25, 
 24, 28, 17, 14, 13, giving a general average of 17 pounds, 7 ounces. 
 With the Ames cement, where 8 pounds pressure was maintained 
 for one minute, the following figures were obtained: 6, 3, 13, 13, o, 
 i7> iij 3 pounds, giving a general average of 8 pounds, 4 ounces. 
 Where the pressure was maintained until setting occurred the 
 Ames cement gave the following figures: 6, 8, 6, 7, 14, 16, 12, 11, 
 iij i3> 12, 9, 8, 10, 7, 8, 7 pounds, giving a general average of 
 9 pounds, 9 ounces. 
 
 Summary. — General average for 8 pounds pressure for one 
 minute only; ivory undercut, porcelain etched: 
 Harvard coarse, 13 lbs., 2 oz. 
 Harvard pulverized, 13 lbs., 4 oz. 
 Ames inlay, 8 lbs., 4 oz. 
 Average, 11 pounds, 8 ounces. 
 
324 MODERN DENTISTRY 
 
 General average for 8 pounds pressure until setting is com- 
 plete : 
 
 Harvard coarse, ii lbs., lo oz. 
 
 Harvard pulverized, 17 lbs., 7 oz. 
 
 Ames inlay, 9 lbs., 9 oz. 
 Average, 12 pounds, 14 ounces. 
 The fact that the Harvard coarse cement does not show 
 greater stress-bearing power when the pressure was maintained 
 until complete setting is possibly explained by the fact that with 
 coarse powder sometimes a particle might be so large as to pre- 
 vent general pressure. Certainly with the Harvard cement it is 
 clear that the finer the powder, the stronger the adhesion and the 
 finer and truer the film. These tests also show that new cement 
 will stick firmly to old cement; that a thin film does not seem 
 to be as strong as a thick film; that ground porcelain and rough- 
 ened ivory have little adhesive power, while etched porcelain 
 has great power of adhesion to cement. This seems at first an 
 anomaly, since etching with hydrofluoric acid has no such power 
 on glass, but a little thought will solve the difficulty. Glass is a 
 homogeneous substance, and etches smoothly and homogeneously, 
 but porcelain, being composed of quartz, feldspar, and flux, 
 etches unevenly in pits and undercuts. 
 
 The fact that the old cement will adhere to the new cement 
 more firmly than the new cement will adhere to the etched 
 porcelain, makes it feasible to fill undercut cavities with cement 
 until setting occurs, and then to cut out of the cement a simple 
 cavity with clean enamel edges. Thus may a difiicult filHng 
 be converted into a simple filling. 
 
 Numerous tests were made with the flat porcelain on which 
 zinc oxid had been fused to see if such porcelain had greater 
 adhesion to the cement than etched porcelain. When zinc oxid 
 was given just the right fusion, |-inch square of porcelain with 
 Harvard pulverized stood as high as 30 pounds pressure, but 
 later fusions of zinc oxid to the porcelain, made with equal care, 
 gave sometimes no adhesion at all, or only 2 or 3 pounds. There- 
 fore, although at first it was thought that the principle of par- 
 tially fusing zinc oxid to the porcelain filling for purposes of 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 
 
 325 
 
 adhesion might prove of value, its unreHabihty finally forced 
 the conclusion that etching with hydrofluoric acid is more feas- 
 ible and trustworthy. 
 
 In order to verify the accuracy of 
 these data it was decided to insert a 
 series of ten porcelain fillings of stand- 
 ard size in a piece of ivory, and after 
 they had been cemented into position 
 imder various conditions with the Ames 
 and Harvard pulverized cements respec- 
 tively, to push the fillings out of the 
 cavities with a plunger inserted from 
 below and attached to a scale. 
 
 The cavities were made and reamed 
 to standard size — 0.3125 inch in diam- 
 eter at the top, 0.125-inch deep, and 
 0,187-inch in diameter at the bottom. 
 Holes about 0.031-inch in diameter 
 were carefully bored in the bottom of 
 each cavity through the piece of ivory 
 to make easy passage for the plunger. 
 The porcelain fiUings were made with 
 the platinum matrices in the usual 
 way, the holes in the bottom of the 
 cavities being temporarily stopped with 
 wooden plugs. The plunger was ce- 
 mented into the inside of a celluloid 
 ring attached to a spring balance. 
 Thus, by inserting the plunger in the 
 holes under the fillings, pressure against 
 the fillings was obtained by a pull on 
 the spring (Fig. 279). When the pres- 
 sure tests were to be made the block 
 
 of ivory containing the cemented inlays was placed upright in 
 a vise. The ring containing the plunger was sHpped over it and 
 the plunger inserted in the hole beneath the fiUing to be tested; 
 then the spring was steadily pulled and pressure made until 
 
 Fig. 279. — Machine for 
 measuring force reqmred to 
 push out a cemented porce- 
 lain inlay: A, ivory block 
 with inlay cemented into 
 position as shown; B, 
 ivory ring fitted with a 
 plunger that is inserted 
 into a hole beneath each 
 filling. Pressure is applied 
 and measured by spring 
 balance 
 
326 MODERN DENTISTRY 
 
 the filling was loosened. The exact pressure reached at the giving 
 way of the fillings was measured by the needle marking a carbon 
 film on the scale, as described previously in the other adhesion 
 tests. 
 
 The first two tests were to obtain the adhesion of perfectly 
 smooth ivory walls to smooth, glazed, closely fitting porcelain. 
 These filHngs were cemented into place with pulverized Harvard 
 cement at thumb pressure for one minute and then allowed to set, 
 care being taken to remove all superfluous cement in the holes 
 under the fillings, so that there would be free movement and 
 apposition of the plunger against the porcelain. The filhngs 
 were then paraffined and placed in water over night. In the 
 morning not one of these fillings stood a pressure of 8 ounces, 
 and most of them came out with very much less. The fillings 
 and cavities were then carefully cleansed of cement with dilute 
 sulphuric acid and washed in alcohol and dried. The filhngs 
 were then recemented into position with the Ames inlay cement 
 with a similar result — no filHng stood more than 8 ounces, and 
 most came out with a pressure of 2 or 3 ounces. These tests 
 proved that plain ivory surfaces in apposition with glazed porce- 
 lain with a thin film of cement did not make a satisfactory union. 
 
 The next two tests were made under exactly similar conditions, 
 except that the fillings were etched with hydrofluoric acid for 
 thirty seconds. The walls of the cavities were smooth and with- 
 out undercuts. The following results were obtained : Harvard 
 pulverized, 37, 28, 47, 96, 20, 30, 34, 66, 88 ounces respectively, 
 average 3 pounds, 3 ounces. Ames inlay, 40, 40, 32, 57, 90, 64, 
 39} 33) 385 37 ounces respectively, average, 2 pounds, 12 ounces. 
 
 In the next tests the cavities instead of being smooth, with 
 sloping walls, were deeply undercut: Harvard pulverized, 8|, 
 9, II, 15!, 7, 6, 13, 14 and 18 pounds respectively, average 11 
 pounds, 6 ounces. Ames inlay, 14, 10, 13I, 7I 7, 17, 11, 13, and 
 17I pounds respectively, average, 12 pounds, 10 ounces. 
 
 In the final tests the fillings were deeply midercut, resembling 
 small coUar buttons, without the slightest attempt being made 
 to fit the cavity except at the margin, and the cavities were more 
 deeply undercut, -to make as great a cement mass around the 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 
 
 327 
 
 filling as possible. The results were as follows: Harvard pul- 
 verized, 32, 25, 24, 23, 20, 18, 28, 30, and 27 pounds respectively, 
 average, 25 pounds, 7 ounces. Ames inlay, 18, 20, 17I, loj, 
 172, 33} 26, and 21 pounds respectively, average, 19 pounds. 
 
 Conclusions on Cement as an Inlay Bond.— These tests and 
 tables indicate: (i) Glazed or ground porcelam and smooth 
 ivory have but little power of adhesion for cement. (2) A thin 
 film of cement is not so strong a bond as a thick mass. (3) The 
 edges of a filHng should be in as close apposition as possible, 
 but wherever feasible the cement that holds the filKng m the 
 cavity should have body and act as a dowel. (4) Etching of 
 porcelain with hydrofluoric acid is a valuable means of obtaining 
 adhesion where the filHng is too shallow for undercuts; but 
 undercuts are to be preferred where they can be obtained, and 
 there is good reason to beheve that the best results are gained 
 by both undercutting and etching the filHng. (5) Fusion of zmc 
 oxid to the porcelain inlay for adhesion purposes is unreliable. 
 (6) Fineness of grit in a cement is more responsible for a fine 
 cement line than pressure. (7) Reduction of the cement grit 
 adds to the strength and power of adhesion. This is a law that 
 appHes to aU cements if they are not thereby made to set too 
 quickly. (8) With Harvard pulverized cement, maintaining 
 the pressure during the complete process of setting sHghtly 
 diminishes the cement line and increases the adhesion 24 per 
 cent. (9) Where the mlay and cavity are sufficiently deep to 
 allow the final expansion characteristic of the Harvard cement 
 during crystaUization to be exerted on the filHng and cavity, 
 maintaining the pressure is only valuable for the sake of apposi- 
 tion, as more pressure is probably obtained by the crystalHzation 
 of the cement than can be exerted by external pressure. 
 
 These tests were made ten years ago, and suice that time 
 Dr. Ames has done magnificent work in evolving cements that 
 are of incalculable value to the profession, and that have now 
 largely replaced the earlier cements. 
 
 Solubility of Cement Line. — When I started to put in inlays 
 I beHeved that an accurately fitting inlay with a so-called perfect 
 edge and microscopic line of phosphate of zinc cement would 
 
328 MODERN DENTISTRY 
 
 preserve its integrity in any mouth where there was proper 
 hygienic care. I believed that the mucin of the saliva acting 
 as a plug in a fine hne would stop osmosis of any neighboring 
 solvent and prevent continued deterioration, and that a coarse 
 Une would not have any such preservative effect, as here the 
 mucin would be constantly changed and washed away. I also 
 held that the more perfectly the inlay fitted the cavity and the 
 less room there was for cement, the greater would be the security 
 against dislodgment. Since that time I have noticed that in 
 some mouths a certain percentage of inlays with perfect adapta- 
 tion will show undoubted signs of discoloration and disintegra- 
 tion at their margins, and that the Httle shallow labial cavities 
 that allow only a thin cement film for retention are the inlays 
 most likely to drop out. 
 
 I decided, therefore, to undertake experiments to determine 
 the relative solubility of thick and thin lines of cement. In 
 preparation for these tests pieces of plain glass were etched 
 with hydrofluoric acid, then creamy cement was firmly pressed 
 between them and allowed to set for fifteen minutes. These 
 pieces of glass and cement were then placed in water and at the 
 end of twenty-four hours the glasses fell apart, leaving free 
 cement films. What was desired was glass so etched that it 
 would permanently adhere to the cement, in order that the action 
 of solvent fluids could be studied on a cement film protected 
 as at the margins of an inlay. Finally, after many experiments 
 it was found that the fumes of hydrofluoric acid would occasion- 
 ally form an undercut etch on glass sufiicient to cause wet 
 cement to permanently adhere to the glass, and in such cases 
 the glass was carefully preserved and cut up into l-inch squares. 
 Agate etched with liquid hydrofluoric acid was found to give 
 permanent hold to wet cement. Therefore, the J-inch squares 
 of glass were cemented to the etched agate and the edges care- 
 fully cleaned. Thus the corroding action of the various solvents 
 on the cement films could be noted, being discernible through 
 the glass with the dark agate as a background. 
 
 Having solved the problem of making cement stick to glass 
 when immersed in an aqueous solution, the next question was 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 329 
 
 to decide on the fluids with which to carry on the tests. Free 
 films of cement and tooth enamel were placed in various solvents 
 such as acetic, valeric, butyric, citric, and lactic acids and c. p. 
 ammonium hydrate (28 per cent.), all of which reagents have been 
 detected in a diluted form in the human sahva. Their effect 
 was primarily tried on natural tooth enamel, because it was 
 considered that fair tests on the solvency of protected cement 
 could only be made with fluids that would not dissolve tooth 
 enamel more rapidly than cement, nor, in fact, dissolve enamel 
 at all, as only such solvents would approximate the conditions 
 found around inlays in the mouth. Natural tooth enamel and 
 thin unprotected pieces of Harvard cement were tested simul- 
 taneously in solutions of various strengths of the solvents just 
 mentioned. For instance, a tooth and cement film when placed 
 in 28 per cent, aqua ammonia showed rapid dissolution of the 
 cement with practically no harm to the enamel. When, how- 
 ever, the ammonia was reduced to 2 or i per cent, it ren- 
 dered the cement film only shghtly defective in the course of 
 some days, and when a film of cement protected on each side 
 by glass and agate was placed in such an aqueous solution of 
 ammonia, the power of osmosis seemed incapable of either 
 weakening or dissolving the cement during a period of months. 
 Therefore, ammonia in any strength that could possibly exist 
 in the mouth was found to be harmless to the cement fine. When, 
 however, lactic, valeric, butyric, and acetic acids were tested, a 
 conclusion was not so readily reached. Anhydrous c. p. lactic, 
 valeric, and butyric acids had, as would be expected, no dis- 
 cernible effect on tooth enamel, and Httle, if any, on cement, 
 except in the case of valeric acid, which made the free cement 
 film defective. But when these acids, as well as acetic and citric 
 acids, were tested in aqueous solutions of from i to o.i per 
 cent., or even 0.05 per cent., the action on tooth enamel was 
 terrific. For instance, i per cent, aqueous solutions of lactic, 
 acetic, or citric acids would roughen enamel in three minutes; 
 in ten minutes a chalky surface appeared, and in twenty-four 
 hours all enamel was practically eaten away. Valeric and butyric 
 acids in i per cent, solutions did not seem to materially hurt 
 
33° MODERN DENTISTRY 
 
 enamel during twenty-four hours, but at the end of three months 
 they had made deep holes in the dentin — a clean scoop with no 
 leathery dentin remaining. These acids, it is true, affected 
 cement fihns in various degrees, but by comparison with their 
 action on enamel the cement was practically permanent, and it 
 was apparent that if we could find a cement that would last in 
 the mouth as much longer than the enamel, as the film of cement 
 outlasted the enamel in these aqueous solutions, we would have 
 a cement that would in ordinary circumstances last many times 
 a man's lifetime. But these results were preposterous, since 
 ordinarily in the mouth the enamel remained while the cement 
 dissolved. Proceeding with the experiments with aqueous 
 solutions and taking lactic acid as a basis, teeth were tested in 
 I : 20,000 lactic acid and water and it was found in three days that 
 the enamel was softened to the cut of a lancet, giving a cheesy, 
 colloid shaving. And yet it must be understood that this amount 
 of acid, powerful as it was, was so minute as to be hardly per- 
 ceptible to any chemical tests. At last, after carrying on innumer- 
 able tests with solutions at blood temperature, it was found that 
 the source of error lay in the use of aqueous solutions, and that 
 saHva solutions should be used if results approximating those 
 found in the mouth were to be obtained. 
 
 For instance, a solution i : 500 of lactic acid and one saliva 
 tested, although it turned blue litmus-paper brilHantly red and 
 had a sharp acid taste, preserved enamel for days or even weeks 
 unharmed. At other times this same person's saliva in lactic 
 acid solutions of from i : 800 to i : 1000 would not be able to pro- 
 tect enamel from decalcification for any length of time. It was 
 also discovered that in saliva solutions the cement was less 
 protected from acid disintegration than was the enamel; it was 
 noted, too, that some saHvas were much better protectives for 
 cement than others. For instance, a i : 1000 solution of lactic 
 acid and one saliva would steadily dissolve cement, while it 
 would not dissolve enamel. A i : 500 lactic acid solution with 
 another sahva would protect both enamel and cement; and as 
 an interesting fact it might be mentioned that cement lasts 
 extremely well in the mouth from which this latter saliva was 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 33 1 
 
 derived. So the problem of what fluids to use in these cement- 
 dissolving tests was solved by using saliva solutions of lactic 
 acid. Lactic acid was chosen not because acetic, citric, butyric, 
 and valeric acids might not also attack the cement in the mouth, 
 but because its action in these tests more nearly represented 
 the kind of decalcification which the author had noted in the 
 mouth. Valeric and butyric acids slightly attack cement, while 
 acetic and citric acids attack it quite vigorously, and it is quite 
 possible that these acids are responsible for the dark cement 
 line that sometimes appears around inlays in the front teeth, 
 these acids being the ones most commonly found in fruit into 
 which the front teeth are apt to be sunk. 
 
 The procedure for testing the solubDity of the cement films 
 was as follows: The above-mentioned j-inch squares of etched 
 glass and etched agate were carefully cleansed and dried. Then 
 finely ground Harvard cement was mixed to a creamy consistence 
 and squeezed between the pieces of glass and agate for about a 
 minute, and the cement allowed to set for fifteen minutes in 
 the air. At the end of that time the edges of the glass were 
 cleansed of cement with a lancet and the protected films placed 
 in a bottle containing the solutions in which they were to be 
 tested. They were then placed in a culture oven where blood 
 temperature was maintained, and observations taken at suit- 
 able intervals. The first action of any dissolution of the cement 
 was noticed when the remnants of the cement film that adhered 
 to the face of the etched agate after the glass had been cemented 
 in place dissolved, leaving the surface of the agate absolutely 
 clean. Any disintegration of the cement film between the glass 
 and the agate was clearly visible through the glass. These 
 tests made with sahva solutions were accompanied by control 
 tests of aqueous solutions of the same strength. 
 
 The first test to be reported was made with a protected film 
 in I : 1000 solution of lactic acid and saliva, and i : looo aqueous 
 solution of lactic acid. To the saliva were always added a few 
 drops of ether or chloroform to prevent fermentation. In one 
 day there was a perceptible fine of disintegration about the 
 glass-covered film in the aqueous solution, which steadily in- 
 
332 MODERN DENTISTRY 
 
 creased. The film in the saliva solution did not show disintegra- 
 tion until the third day. At the end of ten days the film in the 
 aqueous solution had dissolved 0.035 inch all around the edge. 
 It took the saliva solution thirty days to accomplish the same 
 result, this test showing clearly that the saliva reduced the speed 
 of the cement disintegration to one-third of what occurred in 
 an aqueous solution. Moreover, lactic acid in this solution made 
 a clean dissolution without causing the cement to become rotten 
 and soft. For final observation the glasses were taken off the 
 films, which were tightly adherent to the agate, and the cement 
 beneath was examined. In each instance what remained was 
 found to be hard and apparently unchanged to the cut of the 
 knife. The films when measured were about 0.0015 inch in 
 thickness, the extra thickness being due to the uneven etching 
 of the glass and agate. Hereafter the ordinary thin film of cement 
 will be considered to be about 0.0015 inch in thickness. 
 
 Tests were next made on cement films in solutions of saliva 
 and lactic acid that would not cut enamel. Cement films, as 
 above described, of about 0.0015 iiich in thickness were placed 
 in a sahva and lactic acid solution, i : 1000, and also in a i : 1000 
 aqueous solution of lactic acid. It might be interesting to note 
 here that lactic acid and saliva, i : 1000 solution, has a decided 
 acid taste. At the end of thirty days the film in the aqueous 
 solution of I : 1000 lactic acid had dissolved to a distance of 
 0.0625 iiich from the edge of the glass, while the film in the 
 I : 1000 lactic acid and saliva solution showed no signs of dis- 
 solution at all. Covered films placed in i : 500 lactic acid and 
 one person's saliva in thirty days showed sHght but perceptible 
 dissolution around the edge of the glass; while a similar test made 
 with another sahva in a corresponding lactic acid solution 
 showed no perceptible deterioration in the cement film. In fact, 
 one of the cement films kept in a i : 500 lactic acid solution with 
 the latter sahva for six months just began to show signs of dete- 
 rioration at the glass edge at the end of that time. Thus, some 
 saHvas unquestionably are better able by far to preserve cement 
 and enamel against acids of a certain strength than are others. 
 Numerous tests with acid solutions made from the salivas of 
 
EXPERIMENTS CONCERNING VARIOUS CEMENTS 333 
 
 various patients conclusively proved that salivas vary in their 
 relative power of restraining acid decalcification both of tooth 
 structure and cement. 
 
 Another test of interest was the following : A covered cement 
 film had been left in a i : looo solution of lactic acid and saliva 
 for two months in the summer, during which time the solution 
 had fermented. The specimen was taken out and found to be 
 apparently unharmed. The specimen was replaced in a fresh 
 solution of lactic acid and sahva, i : 300. At the end of twenty- 
 four hours the author was astonished to find the cement film 
 dissolved 0.0625 inch from the edge of the glass. A further 
 immersion in the i : 300 lactic acid and saliva solution made 
 only the slow progress one would naturally expect. At the end 
 of ten days the glass was pried off, and the remaining cement 
 was very adherent and apparently unsoftened, as shown by the 
 knife. This test seemed to show that during the summer, al- 
 though the edge of the cement film had been rendered defective, 
 the I : 1000 lactic acid and sahva could not entirely dissolve it, 
 and that a solution of i : 300 lactic acid and sahva later readily 
 dissolved the rotten portion in a few hours, while the gradual dis- 
 solution of the normal cement went on with the ordinary speed. 
 
 Tests were then made to show the relative speed with which 
 a thick and a thin cement film would dissolve in a given solution. 
 Covered films 0.0015 inch thick, as above described, were used 
 for thin films and a thickness of about 0.004 inch for the thick 
 films. The thick films were made by squeezing the cement 
 between agate and glass held apart with several layers of plati- 
 num foil, o.ooi inch in thickness, folded together. The thin 
 film, 0.0015 inch, dissolved twice as fast as the thick film. In 
 fact, during a period of two months the thin film had dissolved 
 0.0625 inch from the edge, while the 0.004-inch film in the same 
 time had dissolved 0.003 inch. The thick and thin films tried 
 in I : 1000 lactic acid and sahva had not dissolved at all during 
 the same time, not even a little film of exposed cement that had 
 not been cleaned from the etched agate. This experiment, 
 many times repeated, was a stumbling-block, as up to that 
 time a very fine joint had been thought to be a protection against 
 
334 MODERN DENTISTRY 
 
 disintegration of the cement around the edge of an inlay. Moss 
 fiber gold was cemented with great pressure between the glass 
 and agate slabs, and the edges trimmed clean and flush with a 
 sharp lancet. This was done to get the finest possible adapta- 
 tion and the thinnest film of cement, so that just as an inlay 
 would be kept from its position by the largest grain of cement, 
 so with the moss fiber gold the apposition might be said to be 
 represented by the smallest cement layer possible, since the 
 large grains of powder would be bedded in soft gold. But these 
 tests only reaffirmed the fact that a thin layer of cement will 
 dissolve more rapidly than a thick layer under similar conditions. 
 And yet this phenomenon, when we come to think it over, is 
 only natural — the less cement there is to be dissolved by a solvent, 
 the more rapidly it will disappear. 
 
 And so, after all that has been said and done, the fine phos- 
 phate of zinc cement film of an inlay is no protection against 
 disintegration; it only looks better, especially if the margins of 
 the inlay tend to discolor. This explains why the old Bing gold 
 inlay lasted so well, consisting as it did of a thin gold shell and a 
 pin cemented into a cavity, both shell and cavity having been 
 filled with cement. Badly fitting though the edges were, the 
 author has seen Bing inlays last for years and does not remember 
 ever having been able to pull one of them out. 
 
 These tests lead to- the following conclusions: (i) In saUva 
 solutions of acid, phosphate of zinc cement ordinarily dissolves 
 more rapidly than enamel. (2) Some saHvas are able to protect 
 the cement from disintegration, and some salivas are not. (3) 
 Where disintegration occurs as the only factor, a fine line of 
 cement will dissolve more rapidly than a coarse line of cement; 
 but where friction and jambing of the carbohydrates into a 
 coarse line occurs by mastication, undoubtedly the cement in a 
 coarse line will disappear more rapidly than in a fine line. 
 
 While the foregoing experiments concerning solubility have 
 not the value that they had at the time they were made, due to 
 the fortunate development of the almost insoluble silicious 
 cements, they are still valuable for what they have shown con- 
 cerning the protective action of saliva. 
 
CHAPTER XII 
 
 STUDY OF THE ROOTS AND GUMS BY MEANS OF THE 
 
 X-RAY 
 
 The x-ray is most valuable as an aid to diagnosis, but, as pre- 
 viously stated, it is not always to be relied upon except as an 
 important link in the chain of evidence on which a scientific 
 diagnosis should be based. 
 
 Many dentists are now using x-ray machines with great 
 benefit to their dental knowledge and technic. In following 
 a root canal it is often of great advantage to stop in the middle 
 of the operation, and leaving the broach in position, to take an 
 x-ray film which will promptly show just how far the canal ex- 
 tends and the distance yet to be explored by the broach. How- 
 ever, a word of caution here may not be out of place. Medicine 
 has had numerous x-ray martyrs who died or were hopelessly 
 crippled in finding out the danger of using x-ray machines with- 
 out adequate protection or instruction; and dentists in using such 
 machines are not only subjecting themselves to a great risk, but 
 they are also subjecting their patients to the danger of burns 
 and permanent deformity. This risk no doubt will only be 
 eliminated when a number of abnormally sensitive patients 
 have been subjected to a too long exposure by the inexperienced 
 practitioner, who does not take the now recognized precau- 
 tionary measures either for himself or his patients. I do not 
 wish to have it inferred that I object in principle to the dentist 
 taking x-ray plates. I only mean to state that a dentist who 
 takes x-ray films and plates should obtain his knowledge under 
 the supervision of an expert rather than at the painful expense 
 of his patients. In the early history of anesthesia deaths 
 from nitrous oxid gas did not occur by the wholesale because 
 at the approach of complete anesthetization the blue skin of 
 asphyxiation warned the untrained dentist that death was 
 hovering near, and so he was scared into a state of proper 
 caution; but with the x-ray machine no such warning is given, 
 
 335 
 
336 MODERN DENTISTRY 
 
 and a burn may be administered by the inexperienced operator 
 that may mar and injure the unsuspecting patient for life. 
 
 Whenever it is possible to have a prehminary study made of 
 the mouth by a series of x-ray plates or films, it should be done, 
 as by this means much valuable information concerning the 
 condition of the roots, alveoH, and peridental membrane will 
 unquestionably be obtained; but we should not forget that the 
 x-ray plates cannot tell the whole story, as some of the following 
 cuts will show, and conditions are pictured concerning pulp 
 canals that appear sometimes worse and sometimes better than 
 they really are. Complete knowledge can only come through 
 the use of three valuable factors: the quaHty of the x-ray plate; 
 scientific interpretation of the plate by the practitioner; and a 
 careful control of the plate findings by judicious comparison 
 with the clinical symptoms of the patient. 
 
 When the diagnosis has been arrived at by means of the 
 factors just mentioned, every area of infection should be treated 
 accordingly. But in interpreting the data it should not be for- 
 gotten that heretofore in dentistry there has been an overzealous 
 tendency to magnify the necessity for the complete filling of 
 root canals to the exact tips. This has been injudiciously claimed 
 to be the only means by which infection at the tip could be ab- 
 solutely avoided. This complete filling of the root canals, as 
 has been shown in Chapter VI, is ordinarily quite impossible, 
 since there are frequently three or even five separate openings 
 at the ends of a root ; and then the mere filling of a root canal to 
 the tip cannot insure against the progressive increase of infection 
 that may have already started in the bone outside of the tooth 
 before the root canal was filled. The dentist's greatest care 
 after a prehminary study of the x-ray plate should be first to 
 see that the tooth is thoroughly sterilized before it is filled ; not 
 the root canal, but the entire internal structure of the tooth; 
 second, to fill it as thoroughly as he reasonably can, with the 
 aid of all the scientific data obtained; and third, to have more 
 x-ray plates taken six months or a year later. At that time if 
 it is found that the tips have healed aseptically, even though 
 the root canals may not be filled to the tip, they can be safely 
 left to take care of themselves. But if areas of infection still 
 
STUDY or ROOTS AND GUMS BY THE X-RAY 337 
 
 appear, even about the apices of perfectly filled roots, there 
 should be surgical interference; the tip should be amputated, 
 the infected bone curetted, and the wound packed with antiseptic 
 gauze until complete heahng is obtained. 
 
 Interpretation of Plates.— The following ^-ray plates are 
 presented with a full appreciation that they have not, ui places, 
 the perfect outUne and clear dehneation found in many other 
 books on this subject. Many of the pathologic conditions shown 
 by the plates are only obscurely demonstrated, but as this is the 
 difficulty that ordinarily confronts us in the interpretation of 
 r^^-ray plates, the plates are presented without being touched up. 
 
 Case No. i (Fig. 280). Here is a case of an active woman, 
 aged forty-five, who in her youth had tuberculosis, but recovered 
 from it. A careful examination of the mouth disclosed no pockets 
 of infection and only an abnormal red line around the necks of 
 the teeth, and yet the x-my plates seem to uidicate that the 
 lime salts are being absorbed from the bones around the teeth 
 in a way characteristic of the beginning of infection. Blood 
 taken from the infected gums shows the presence of Streptococcus 
 viridans, hemolytic streptococcus, and Bacillus influenzse. The 
 patient also had osteophytes in the knee and in the lumbar 
 vertebra, and certainly needed treatment, systemic rather than 
 local, since the local condition could be readily controlled by 
 mouth scrubbing and local cleansing, as described in Chapter II. 
 Vaccine treatment was given, the vaccine being made from the 
 germs found in the blood from the gums. 
 
 Case No. 2 (Fig. 281). The next case is of a woman aged 
 forty-three. The films show an apparently normal condition 
 of the tips and the alveolar process, with the single exception 
 of the anterior root of the left lower second molar, which has a 
 spot of infection and indicates that the root canals will have to 
 be opened and treated with Buckley's mixture; and if this is not 
 successful the root must be excised from the rest of the tooth 
 and extracted. However, the shadow upon the tip of the anterior 
 root is accentuated by the fact that it lies in the line of the inferior 
 dental canal, and therefore may not be so seriously involved 
 as it appears to be. And yet a careful study of the bony structures 
 
338 
 
 MODERN DENTISTRY 
 
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STUDY OF ROOTS AND GUMS BY THE X-RAY 
 
 339 
 
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 MODERN DENTISTRY 
 
 generally indicates a lack of lime salts, and consequently a lowered 
 bacterial resistance of the bone. Such a diagnosis, however, can 
 only be made when the dentist knows just how long the exposures 
 were made and what tubes were used. 
 
 Case No. 3 (Figs. 282-284). This case is of a woman forty- 
 two years of age who had recovered from tuberculosis of the 
 lungs some ten years previously. Her right knee was badly 
 infected and enlarged to twice its size, with marked crepitus, 
 and yet the x-ray of the knee-joint, because the infection is still 
 
 Fig. 282. — Case 3. Right knee, the bone of which seems normal and yet the 
 knee was swollen to twice its normal size. It lost its swelling and shortly returned 
 to normal condition when three badly fitting shell crowns were removed from th^ 
 two right lower molars and second bicuspid. (Plate made by Dr. Willis F. Manges.) 
 
 confined to the soft tissues, reveals nothing. The radiograph 
 study of the mouth and also of the knee are shown. The x-ray 
 shows nothing abnormal at the tips of any of the roots except 
 in the case of the right lower first molar. The rarefied bone in 
 the upper jaw was not associated with pockets; the gum was in- 
 flamed, but not to the point of breaking down. The patient, 
 however, had not used floss-silk nor kept the back teeth free 
 from bacterial deposits. Just before the x-ray plate was made 
 three gold shell crowns that were collectors of foul infection 
 were removed from the first and second right lower molars 
 
STUDY OF ROOTS AND GUMS BY THE X-RAY 
 
 341 
 
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342 MODERN DENTISTRY 
 
 and the lower right second bicuspid. The knee began at once 
 to improve. What the author wishes to emphasize in this case 
 is that serious external mouth infection, not discoverable by 
 the x-rs^y, obviously caused the serious knee inflammation, 
 because when the external infection was removed, the swelling 
 and inflammation in the knee began rapidly to subside. An 
 attempt was made to extract the lower right first molar, and as a 
 preHminary precaution the tooth was cut into two parts so that 
 the roots would be separate from each other, but it was impossible 
 to get them all out at the first operation without causing exces- 
 sive laceration. The roots broke, leaving about one-third of each 
 root in the jaw bone. These root tips were allowed to remain, and 
 were easily removed in the course of a month, when the inflam- 
 mation had loosened them and caused them to float near the 
 surface. The excessive tightness is interesting in the light of 
 
 Fig. 284. — Case 3. Shape of tips of roots due to the exostosis. 
 
 the area of infection at the tips. The tips, when extracted, were 
 found to be of the shape shown in Fig. 284, which accounted for 
 the difficulty encountered in the extraction. It will be observed 
 that the x-ray plates gave some warning of the exostosis, but 
 did not picture it completely. The enlargement was in the line 
 of the x-rays and the consequent difficulty of extraction was not 
 made fully obvious. The removal of the tips at the time of ex- 
 traction would have been attended with great danger of frac- 
 turing the jaw, and yet four weeks later the inflammatory proc- 
 ess made it possible to easily remove the broken ends with the 
 simple pry of an elevator. Had it not been for the systemic 
 condition I am convinced that judicious canal treatment would 
 have been justified and would probably have saved the tooth. 
 The point of interest about the case is that the areas of decal- 
 cification in the alveolus, being general, were not such as to im- 
 peril the teeth or body if judicious cleansing had been maintained; 
 
STUDY OF ROOTS AND GUMS BY THE X-RAY 
 
 343 
 
 and the only tooth that did show a darkened area of inflammation 
 was so firmly lodged that it would not come out whole. The mere 
 removal of three infecting overhanging crowns caused the acute 
 symptoms in the knee to abate, and an autogenous vaccine was 
 used to raise the germicidal power of the blood, thereby effecting 
 a complete cure. 
 
 Case No. 4 (Fig. 285). The next case is that of a married 
 woman aged thirty-six, whose three elder sisters had died in 
 infancy from hereditary syphiHs. Plates are shown of the in- 
 fected upper and lower incisors as indicating the condition 
 when the patient was first examined. Mark the darkened areas 
 
 Fig. 285. — Case 4. Necrotic areas at tips of roots A and B due probably to 
 hereditary syphilis. Pulp alive in upper central incisor. Note white line of bone 
 extending from apical foramen of the upper central incisor to healthy bone beyond. 
 (Films made by Dr. Willis F. Manges.) 
 
 of infection above the superior left central and lateral incisors, 
 and below the lower left lateral incisor. The patient suffered 
 excessively from a burning sensation in the tip of the tongue 
 that was reflected into the sublingual glands and the glands of 
 the neck. The lower left incisor, marked A, was extracted, 
 the bone drilled away, and the opening packed with sterilized 
 gauze. All of the black bone that was not removed by the prim- 
 ary operation was removed with an excavator during the sub- 
 sequent daily dressings. Occasional applications of aromatic 
 sulphuric acid were made which expedited the separation of the 
 unhealthy from the healthy tissues. At the end of a week the 
 entire wound was clean, pink, and covered with healthy granu- 
 
344 MODERN DENTISTRY 
 
 lations. It was then allowed to fill up and the wound closed 
 satisfactorily. Immediately after the cutting away of the dead 
 bone the tongue symptoms were greatly ameliorated. During the 
 period of inflammation they again appeared, but finally, when 
 the wound entirely healed, they were greatly improved, although 
 not entirely ehminated. In the meanwhile the patient was having 
 a course of mercurial treatment on account of the hereditary 
 sj^hilitic history. It was next determined to extirpate the 
 infected area over the left upper superior central and lateral 
 incisors, marked B. It will be interesting to know that the pulp 
 in the central incisor was alive, and the course of the blood-vessels 
 can be seen in the plate, running through the thin septum of 
 bone that had not yet become broken down. Novocain and 
 suprarenin were injected and the bone drill inserted through 
 the gum into the infected region, which was found to be black, 
 cavernous, and far-spreading in various small tentacle-like pro- 
 jections. To have cut all the black bone out at the first operation 
 would have meant the loss of the teeth as far as the first bicuspid 
 on one side and the lateral incisor on the other. Therefore, the 
 tips of the lateral and central incisors were amputated, the pulp 
 canals cleansed and filled with Buckley's mixture of tricresol 
 and formahn, and the wound packed with sterilized gauze. The 
 next day the dressing was removed and aromatic sulphuric 
 acid was applied for three minutes on a pellet of cotton, and the 
 wound repacked with gauze. This was repeated on the fourth 
 day, and by this time the wound was spread open, the tips of 
 the amputated tips were exposed, and the black remnants of 
 bone so softened and loosened that they could be easily picked 
 out with a spoon excavator, leaving only living, sensitive bone 
 and the bottom of the wound clean. No such wound should 
 be allowed to heal up while there is any insensitive bone left at 
 the bottom. To do so spells failure and probably a recurrence 
 of decay. When this had been accomplished the upper left 
 central and lateral incisors were again opened and the canals 
 resterilized. Gutta-percha cones were then forced into the canals 
 until they projected through the foramina, the gutta-percha 
 trimmed off at the tips with a hot instrument, and the teeth 
 
STUDY OP ROOTS AND GUMS BY THE X-RA.Y 345 
 
 then completely and permanently filled with cement. After 
 this the wound was kept open with gauze until the granulations 
 filled up to a point where the wound was more shallow than 
 broad, care being taken to see that the bottom was entirely 
 covered by sound, healthy tissue. The use of a flap of gum and 
 the blod-clot method, in this instance, would have been hopelessly 
 inefficient. Bone operations about the teeth roots can hardly 
 ever be based on the supposition of asepsis. Such a wound 
 practically always contains infected material, and drainage is 
 always necessary. This wound healed satisfactorily and the 
 incisors were saved. 
 
 Case No. 5 (Fig. 286). This case^ shows another illustration 
 of a darkened area of bone at the tip of a root, indicating evident 
 infection, although the root contained a Hving pulp. The tooth 
 referred to is the left upper bicuspid supporting the bridge. This 
 case is that of a woman suffering from secondary anemia. Four 
 years previously she had a hemoglobin of 30 per cent, and had 
 become so weakened that she had lost the use of her legs. She 
 was put to bed for six months, and under medical treatment 
 her hemoglobin rose to 75 per cent. Since that time she had 
 been steadily relapsing, and when the author first saw her the 
 hemoglobin of the blood had again dropped to 30 per cent., 
 poikilocytes, macrocytes, and microcytes being present. An 
 autogenous vaccine was prepared from material taken from a 
 pus pocket in the gum around the tooth C. The left upper 
 second bicuspid, marked A, was extracted, the anterior buccal 
 root of the right upper second molar, B, cut loose and extracted, 
 and the lower right second molar, C, that showed an area of 
 infection at the tips, also extracted. In three days the poikilo- 
 cytes disappeared, the red cells had increased from 3,616,000 
 to 3,960,000, and the patient felt distinctly stronger. The 
 vaccine treatment was started, the mouth put in hygienic con- 
 dition, and the teeth restored so as to perform their proper func- 
 tions for accurate mastication by means of cleansable fillings, 
 crowns, and bridges. The great point of interest in the case Hes 
 in the fact that the mere removal of the three roots could have 
 
 1 See page 106. 
 
346 
 
 MODERN DENTISTRY 
 
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STUDY OF ROOTS AND GUMS BY THE X-RAY 347 
 
 in three days caused a rise of seven points in the hemoglobin and 
 a disappearance of poikilocytes. At the end of two months the 
 patient returned to her home in the West and the vaccine treat- 
 ment was continued there. In four months after the treatment 
 was inaugurated the hemoglobin rose to 67 per cent. After that 
 she steadily improved until her health was completely restored. 
 Case No. 6. The next case is that of a man aged forty-five, 
 who had been suffering from severe neuralgic pains in the right 
 side of his head. The x-yslj plate (Fig. 287) shows a superior 
 second bicuspid that had an area of inflammatory infiltration 
 with a projecting point of gutta-percha at the tip. The bone 
 
 Fig. 287. — Case 6. Second bicuspid tip showing projecting root canal fillin g 
 and infected bone area. The tip was amputated and a neuralgia of two years' 
 standing at once disappeared. (Film made by Dr. Willis F. Manges.) 
 
 over the tip was anesthetized with novocain, the area drilled 
 out, and the tip of the root smoothed. This simple operation 
 alone caused his headaches to disappear permanently. This is 
 especially interesting as it shows how slight an irritation at the 
 tip may cause a reflex action. And is is especially of interest to 
 consider, if so minor a spot of irritation happened to cause so 
 marked a neuralgia, might it not have easily caused other types 
 of systemic disorders that were nevertheless serious, although 
 their presence may not have been made manifest by the symp- 
 toms of pain? This man also had a case of general mouth in- 
 fection that necessitated treatment for over three years before 
 it could be controlled. Figure 288 shows his right shoulder 
 
348 
 
 MODERN DENTISTRY 
 
 containing marked osteophytes; and Fig. 289 is a picture of 
 the same shoulder taken three years later, showing the absorp- 
 
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 tion of the osteophytes so that the joint is practically normal. 
 When this patient first came under observation he had contem- 
 
STUDY OF ROOTS AND GUMS BY THE X-RAY 349 
 
 plated an operation for having the osteophytes removed from 
 the head of the humerus. The author advised against it and told 
 him to await the effect of the mouth treatment and the vaccine. 
 At that time he was having acute pains in his shoulder and could 
 hardly move the arm. The treatment produced such beneficial 
 results that the patient decided against an operation. At the 
 end of three years the osteophytes had disappeared, there was 
 no longer any pain, and his arm had regained its normal power 
 of movement. 
 
 Fig. 290. — Case 7. Gutta-percha projecting beyond tip of bicuspid necessitating 
 root excision. (Plate made by Dr. Willis F. Manges.) 
 
 Case No. 7. This case shows a well-marked bhnd abscess 
 at the tip of a root, shown by the dark area of inflammation 
 at the tip of the lower second bicuspid (Fig. 290). The gutta- 
 percha root canal filling protrudes through the apical foramen 
 into the abscessed region. The value of the x-ray plate is here 
 made apparent, for this condition would not have been allowed 
 to exist had an :r-ray plate been made at the time the root was 
 filled. Moreover, the gutta-percha would not have protruded 
 
350 
 
 MODERN DENTISTRY 
 
 if the gutta-percha point with the oil of eucalyptus had been used 
 as described in Chapter VI. There were only two possible 
 remedies — one was to extract the tooth; the other was to anesthe- 
 tize the gum and bone over the tip and amputate the lower 
 portion of the root, leaving the end smooth and even. This latter 
 was done and the tooth has been giving good service ever since. 
 It will be noticed that the infected region lies close to the mental 
 foramen. When the operation of excision was performed the 
 patient was warned that he might lose sensibility of the lower lip 
 on that side. Immediately after the operation it was found that 
 the sensibility was unimpaired; but later the inflammation 
 
 Fig. 291. — Case 8. Posterior root excised of molar marked A. Crowned 
 according to Fig. 292. Molar marked B hopelessly infected. Extracted and 
 replaced by removable bridge. (Films made by Dr. Willis F. Manges.) 
 
 spread and the nerve trunk at the mental foramen became in- 
 volved, and he lost sensibility in the right side of the lower lip 
 for three months. Since that time, however, the normal sensi- 
 bility has returned and the mouth is comfortable. 
 
 Case No. 8. This patient, a man aged forty-five, had two 
 lower molars that were infected at the tips — the right lower 
 second molar, marked A, and the first lower left molar, B. The 
 two cases would have appeared equally difficult to manage 
 without the aid of the x-ray plate. The left lower first molar 
 roots, B, were extracted, being hopelessly infected, and the molar 
 replaced by a removable bridge. The anterior root alone of the 
 right second molar was extracted, leaving, as the plate shows, a 
 
STUDY OF ROOTS AND GUMS BY THE X-RA.Y 
 
 351 
 
 healthy posterior root, A, on which a satisfactory crown was 
 constructed which entirely filled the space, and which has been 
 doing good service for over a year and a half (Fig. 292). It 
 was constructed as follows: The crown of the anterior adjacent 
 tooth was composed almost entirely of amalgam. Let A repre- 
 sent the anterior tooth; B the remaining root of the tooth from 
 which the anterior root has been extracted. A platinum band 
 was fitted to the projecting portion of B. Porcelain was built 
 up on the band to form a crown, C, with a notch on the side. Then 
 crown, A, was enlarged by the amalgam addition, D, so that 
 it fitted into the adjacent 
 porcelain crown. To make 
 the portion Z), the crown. A, 
 was well undercut and soft 
 amalgam added and dried of 
 its mercury by sponge gold. 
 When this was polished the 
 floss-silk could be passed be- 
 tween the amalgam and the 
 porcelain crown for the daily 
 cleansing, and yet the ledge 
 of amalgam formed a perfect 
 support for the porcelain dur- 
 ing the stress of mastica- 
 tion. In this way the tooth 
 function was as hygienically 
 maintained as it was prior 
 root. 
 
 Case No. 9 (Fig. 293). The x-ray plate shows that the 
 roots of the right lower second molar were so badly infected that 
 the tooth had to be extracted. The tips were found to be necrotic. 
 The tooth was replaced by a removable bridge. The two upper 
 left bicuspids were opened on account of the darkened area at 
 the root tips, and were given a course of sterilization, filled with 
 gutta-percha cones that were pushed into position through 
 eucalyptus oil until the tips wedged. The cones were then packed 
 thoroughly into the canal with warm instruments. The first 
 
 Fig 292. — Case 8. A, first molar 
 with large amalgam filling in crown; 
 B, posterior root of second molar, ante- 
 rior root having been excised; C, porce- 
 ain crown with platinum shell for reten- 
 tion; D, amalgam addition to molar A 
 to make a side support for crown C. 
 
 to the excision of the anterior 
 
352 
 
 MODERN DENTISTRY 
 
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STUDY OF ROOTS AND GUMS BY THE X-RAY 353 
 
 wedging of the cones at the tips prevented any possibiHty of the 
 liquid gutta-percha being driven through the apical foramen. 
 The gums over the darkened areas of the tips were stimulated 
 once a week for several weeks by appHcations of the violet ray, 
 which greatly aided the restoration of the vitality of the infected 
 areas. The tip of the right upper second bicuspid also was treated 
 in a similar manner, although excision of the root tip through the 
 alveolus might have been advisable. The impacted upper wis- 
 dom teeth were left undisturbed, as they were apparently causing 
 no reflex disturbance. If, however, neuralgia should develop 
 or even any serious, unexplainable systemic symptoms arise, 
 however far removed, the extraction of such teeth should always 
 be held under consideration. The bones around the lower in- 
 cisors unquestionably have lost a portion of their Kme salts, but 
 a rehef from the irritation of the general mouth infection will 
 allow the forces of recuperation in the bones to assert themselves. 
 Case No. lo (Fig. 294). In the next case we have a similar 
 appearance, but more marked, of the loss of the lime salts in 
 the tips of the left upper central incisor and left upper lateral 
 incisor, in which teeth the pulps are alive and without the a;-ray 
 would have been considered normal. The bone around the tips 
 has started to degenerate, and unless it can be stimulated to 
 health, will unquestionably in time require the bone drill. Appli- 
 cations of the violet ray or electrolysis in this region wiU be val- 
 uable; but if these are not successful in controlling the infection 
 the canals will have to be opened, cleaned out, and filled, in 
 spite of the fact that the pulps in both teeth are alive and show 
 no physical signs of disturbance. The right upper lateral in- 
 cisor and left upper second bicuspid gave no evident clinical 
 signs of disorder, and yet the pulps are dead and the tips seem 
 unquestionably absorbed. The bony areas require that the root 
 tips should be excised and that the adjacent area of lowered 
 vitaHty in the bone should be stimulated to healthy growth. 
 These tips are only less diseased than the left lower second bicus- 
 pid and left lower molar, the roots of which have become hope- 
 lessly absorbed. These teeth will have to be extracted and re- 
 placed by a removable bridge. The bridge replacing the lost 
 23 
 
354 
 
 MODERN DENTISTRY 
 
 
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STUDY OF ROOTS AND GUMS BY THE X-RA.Y 355 
 
 right lower second bicuspid has been in position many years, 
 and is doing excellent service. It is composed of an inlay in 
 the molar to which a gold cap for the retention of a cemented 
 tooth and spud have been attached. It will be noted that the 
 tips of the second molar are in good condition. The lack of cal- 
 cic salts in the alveoli around the lower incisors indicates an 
 infection, and the need of careful cleansing with fioss-silk and 
 brush and a raising of the bacterial resistance with bacterial 
 vaccine. 
 
 Case No. ii. The next case is that of a man aged forty-eight 
 years, who has been under the author's care twenty-five years. 
 The work looks '^pretty poor," but a great deal of it was early 
 practice work, and since the patient was perfectly comfortable 
 there never seemed to be any necessity for changing it. But 
 finally, although his mouth was still comfortable, he began to 
 show symptoms of toxemia, the cause of which his physician 
 was unable to locate. The radiograph, however, was most 
 enlightening. All of the bicuspids except the right lower first 
 bicuspid were extracted. They are marked A, B, C, D, E, F, G 
 (Fig. 295). All had tips denuded of peridental membrane, and 
 cementum dissolved and roughened with sharp points. The 
 first lower right bicuspid, marked H, that has a much deeper 
 shadow than the others, had a Hve pulp which was removed, 
 with every chance that the tip would recover under the healing 
 effects of asepsis and electrolysis. In Fig. 296 B represents 
 the extracted root of the left upper first bicuspid, and G the 
 extracted root of the lower second bicuspid. These are typical 
 of the way all the extracted bicuspids appeared. The anterior 
 palatal root of the left upper second molar was excised and removed 
 by means of the elevator. The right upper first molar was opened 
 and a cotton dressing of years standing was disclosed. Oh, 
 Shade of Flagg! The dark areas over the upper central incisors 
 should also be noted, merely to show how much the anterior 
 palatal foramen may resemble an area of infection. 
 
 Case No. 12. The plate (Fig. 297) shows three right lower 
 molars. The first molar, marked A, is sufficiently sound to be 
 treated externally with the violet ray and the dry cell battery,, 
 
356 
 
 MODERN DENTISTRY 
 
 
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STUDY or ROOTS AND GUMS BY THE X-RAY 
 
 357 
 
 Molar C also seems sound, but the anterior root of molar B is 
 badly infected, as is shown by the plate. This tooth was ex- 
 cessively sensitive to the shghtest touch. The anterior root of 
 molar B was extracted, leaving the posterior root in position. 
 Figure 298 is a photograph of the extracted root with the abscess 
 
 Case II. 
 
 sac attached. Being a recently acute condition, the sac was still 
 in position, but later on chronic suppuration would have set in, 
 and the membranous condition would have been replaced by 
 a necrotic cavity of bone. 
 
 Fig. 297. — Case 12. Anterior 
 root of B excised through the crown 
 and extracted (Fibn made by Dr. 
 Willis F. Manges.) 
 
 Fig. 2c 
 
 -Case 12. Extracted anterior 
 root of molar B. 
 
 Case No. 13. Figure 299 pictures an apparently similar 
 inflammatory condition of the right lower second molar root. 
 And yet the photograph of the extracted root (Fig. 300) shows 
 that the conditions were more advanced. The abscess sac had 
 been completely absorbed and the cementum at the tip has been 
 denuded of its membranous covering. In this case there was 
 no pain or discomfort and the root was extracted on the evidence 
 of the x-ray plate. 
 
3S8 
 
 MODERN DENTISTRY 
 
 Case No. 14 (Fig. 301). The next case is that of a woman, 
 aged twenty-nine years, very poorly nourished. The fihn of 
 the lower incisors is missing, but the other illustrations will show 
 that a marked destruction of bone and peridental membrane 
 has occurred. Her teeth were loosening and spreading in all 
 directions, but a study of the plates indicated that the mem- 
 branes and bone around the root tips were still in a healthy 
 condition. The teeth were drawn into place by twisted silk. 
 Mouth hygiene was inaugurated, with applications of ammonium 
 bifluorid comp., and last, but not least, an autogenous vaccine 
 was given once a week. The patient made a rapid recovery, 
 gained weight, her teeth became firm, and the gums healthy. 
 
 Fig. 2Q9. — Case 13. First molar 
 infected at tip. Note photograph of 
 extracted tooth. (Film made by Dr. 
 WiUis F. Manges.) 
 
 Fig. 300. — (Zase 13. Photograph 
 of extracted first molar. Tip de- 
 nuded of peridental membrane and 
 roughened. 
 
 Case No. 15 (Fig 302). This case is that of an unmarried 
 woman of thirty-seven years. It will be noted that the left lower 
 first molar and second bicuspid and the first lower right bicuspid, 
 marked respectively. A, B,C, have areas of infection at the tips. 
 Observe the photographs of the extracted teeth (Fig. 303). 
 Their pulp canals had been filled years previously with cotton, 
 a fact which the x-ray did not, of course, discover. The molar 
 root tips, A , were found to be necrotic, without enlargement of 
 the cementum. The second bicuspid, B, was denuded of its 
 peridental membrane at the tip, but otherwise, with the exception 
 of a slight exostosis, was normal. The right lower first bicuspid, 
 C, had an exostosis half-way down the root to the tip with a small 
 peridental sac at the end. The exostosis at the tip of the left 
 
STUDY OF ROOTS AND GUMS BY THE X-RAY 359 
 
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360 
 
 MODERN DENTISTRY 
 
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STUDY OF ROOTS AND GUMS BY THE X-RAY 36 1 
 
 lower first bicuspid is of interest, and the fact that extraction was 
 unnecessary was a source of congratulation. The. upper right 
 first molar had to be extracted owing to absorption of the buccal 
 roots and infection at the tip of the lingual root. 
 
 Case No. i6 (Fig. 304). Note especially the right upper 
 lateral incisor containing a living pulp and the first buccal root 
 of the left upper first molar where the pulp had died. The former 
 was extracted and the buccal root of the latter was excised at 
 the bifurcation. It will be noted that the other bony processes, 
 although absorbed, are unusually retentive of their lime salts, 
 indicating good bacterial resistance of the patient, which proved 
 to be the case. The patient is a vigorous, active man of fifty, 
 and responded with great readiness to the vaccine treatment 
 after the two infecting roots were extracted and careful mouth 
 
 I 
 
 ABC 
 
 Pig 203. — Case 15. Extracted teeth. Excessive exostosis in B and C. 
 
 hygiene instituted. In spite of the loss of bone around the lower 
 incisors, they are perfectly firm under mastication, owing to the 
 healthy condition of the peridental membrane that yet remains. 
 If, however, this should get infected, the teeth will loosen and 
 be lost almost immediately. 
 
 Case No. 17 (Fig. 305). The next plate is of a young un- 
 married woman of twenty-seven. The patient showed marked 
 mouth infection, especially of the soft tissues, associated with 
 great general weakness and loss of vitahty, a slight overtendency 
 to fat, but previously athletic and active. The two lower sixth 
 year molars are infected at the root tips. These were extracted 
 and showed inflammatory membranous sacs at the tips, smaller, 
 but nevertheless of the same type as the root shown in Fig. 298, 
 Case No. 12. But the point of particular interest in this case 
 
362 
 
 MODERN DENTISTRY 
 
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STUDY OF ROOTS AND GUMS BY THE X-RAY 
 
 363 
 
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364 MODERN DENTISTRY 
 
 lies in the general absence of lime salts in the bones, especially 
 around the upper bicuspids and the lower incisors. This indicates 
 a tendency for the breaking down of all the tissues. The mouth 
 was placed in a satisfactory hygienic condition and autogenous 
 vaccine given with beneficial results. 
 
 Case No. 18 (Fig. 306). This skiagraph portrays the lower 
 central incisors showing an area of decalcification at the tip 
 of the right central incisor. This was supposed to be a spot 
 of infection, and marked as such by a prominent x-rsij man. 
 But the tooth gave normal responses to heat, and a close study 
 of the plate will show that the lacunae are present in the decalci- 
 fied area, showing that the bone is not broken down. A later 
 study of the mouth is shown by the larger plate (Fig. 307). 
 
 Fig. 306. — Case 18. Supposed spot of bone infection marked by arrow. 
 
 The right first lower bicuspid contained a cotton root canal 
 dressing that had been slowly spreading infection in the root under 
 the crown ever since the crown was inserted — a period of some 
 five or six years. The right upper first bicuspid that was ex- 
 tracted shows a slight infection of the buccal root, the Jingual 
 root appearing normal. There is little doubt that the root might 
 have been saved if general symptoms of rheumatism had not 
 demanded its removal. The right lower second molar had a 
 membranous sac on the tip with a certain amount of absorption 
 of the alveolar process around it. The dark line in between the 
 roots of the left lower molar did not indicate a breaking away 
 of the peridental membrane from the tooth or any real pocket 
 of infection. It only shows a loss of lime salts in the bony tissues. 
 
STUDY OF ROOTS AND GUMS BY THE X-RAY 
 
 36: 
 
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366 MODERN DENTISTRY 
 
 Case No. 19 (Fig. 308). The lower second bicuspid shows 
 so apparent a spot of infection at the tip that the local dentist 
 on the evidence of the x-ray plate had drilled into the tooth only 
 to find the pulp alive and apparently normal. He was conse- 
 quently at a loss to understand the defined darkened area and sent 
 the plate to me for examination. To my mind it was plainly 
 a case of enlarged mental foramen. In the x-ray plate the mental 
 foramen is apt to appear as a dark spot and great care must be 
 
 Fig. 308. — Case 19. Darkened area at tip of second bicuspid is not a chronic 
 abscess — it is the mental foramen. 
 
 taken in differentiating it from a spot of infection by clinical 
 evidence. 
 
 Case No. 20 (Fig. 309). This case is that of a man of forty- 
 three years, of fairly good health, but who for the last four or 
 five years has suffered from progressive nervousness with a tend- 
 ency to get tired easily. His mouth had been looked after by a 
 happy-go-lucky dentist who still uses cotton as a pulp canal 
 filling. The patient for years has used a tooth-brush without 
 cleansing his teeth. This case will be discussed in detail, as 
 the study of the extracted roots serve as a key for solving the 
 condition of the whole mouth. The first two teeth that will 
 be noted are the lower second molar, A, and the upper first 
 molar, B. The anterior root of the right lower molar was excised 
 by cutting the crown in half, according to the dotted line, from 
 the bifurcation of the roots up to the grinding surface. In 
 Fig. 310 ^ represents the excised half of the tooth which was 
 
STUDY OF ROOTS AND GUMS BY THE X-RAY 
 
 367 
 
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368 MODERN DENTISTRY 
 
 found to have two distinct roots with absorbed and necrotic 
 tips. Note the type of shadow around this tip in the plate 
 (Fig. 309). It is extremely faint and the lines of demarcation 
 in the adjacent bone are most indistinct. When we examine 
 the bone next to the normal root, which bone was found to be 
 living, containing canahculi, the shadow is far greater than in 
 the spot where bony absorption was complete and the peridental 
 membrane completely destroyed. The bone at the bifurcation 
 of the two roots was alive and healthy to the cut of the bur, 
 merely showing a sHght loss of density, indicating that it had 
 begun to lose its lime salts, while the same bone immediately 
 adjacent, that has much less of a shadow, had lost all of its 
 lime salts and organic structure. The infected area clinically 
 
 A B 
 
 Fig. 310. — Case 20. Root marked A, remarkable as it is, is a bifurcated ante- 
 rior root of lower second molar. As can be seen, the root tips were necrotic and 
 absorbed. Tip of the extracted root, B, was almost, if not quite, normal, and yet 
 it appeared badly diseased in the plate. 
 
 was nevertheless much in evidence, and yet, when studied by 
 the x-ray, the Hne between the healthy and unhealthy bone 
 became so indistinct as to require the closest observation for its 
 detection. The upper first molar has a decided area of calcic 
 absorption around the anterior buccal root. The buccal root 
 was found to be filled with cotton, while the palatal root contained 
 gutta-percha. It was decided to excise the anterior buccal root 
 from the rest of the tooth, both for the sake of saving the tooth 
 and in order that it might be possible to examine the extracted 
 root and adjacent bone for the purpose of determining the mean- 
 ing of the changed bone around the roots of the upper bicuspids, 
 canines, and incisors. It will be seen from the x-ray plates that 
 the bones around the tips of the bicuspids and canines are appar- 
 
STUDY OF ROOTS AND GUMS BY THE X-RAY 369 
 
 ently more lacking in lime salts than the bone around the tip 
 of the buccal root that was extracted. There is no absorption 
 of the tip, and a macroscopic examination of the root showed 
 that it contained a moderately healthy tip with an adherent 
 peridental membrane that was perhaps slightly thickened 
 (Fig. 309, B). This fact convinced the author that antiseptic 
 treatment and filling combined with external electrolysis might 
 have been amply able to restore health to the complete tooth. 
 The tooth, A, was then restored to normal occlusion by carving 
 the crown and building it up to proper contour with porcelain. 
 The pulp in the right upper lateral incisor proved to be dead 
 and putrescent, although the bone at the tip did not seem es- 
 pecially unhealthy. Strangely enough, it gave a sharp thrill 
 under the application of the cautery, which at first seemed to 
 indicate that the pulp was aHve, but later tests and further 
 analysis of the plate convinced me that the pulp, even if it were 
 alive, should be removed. I then found on opening this tooth 
 that the pain from the cautery application had arisen from the 
 e3q)ansion of the heated gas sealed within the canal, making 
 pressure upon a sensitive, inflamed apical foramen. The right 
 upper central incisor also had a putrescent pulp, but it gave no 
 response to the application of heat. All of the upper teeth, 
 where there were bony changes similar to those that had occurred 
 in the upper extracted molar root, were filled, with the full con- 
 viction that antiseptic dressings and fillings, combined with 
 external electrolysis and mouth hygiene, would be amply able to 
 restore the tissues to health. The case is kept under observa- 
 tion, and if a later x-ray plate shows that complete healing has 
 not taken place amputation of the tips of the roots will be neces- 
 sary. 
 
 Case No. 21 (Fig. 311). This represents the mouth of a 
 woman of seventy, well preserved and active. The plates show 
 a general loss of bony substance that at her age might be called 
 normal, although in a person of thirty it would be considered 
 a sign of some depressing systemic infection. All of the teeth are 
 firm with the exception of the left lower second molar, marked A . 
 This was quite loose, and a careful examination will show the 
 24 
 
37° 
 
 MODERN DENTISTRY 
 
 P^ 
 
 U 
 
 
 
 X! • 
 
 ^ s 
 
 > 
 
 *liiilllh 
 
 U 
 
STUDY OF ROOTS AND GUMS BY THE X-RAY 
 
 371 
 
 faint area of tissue change that was noticeable in the previous 
 case around the lower molar root that had to be extracted. 
 This tooth was extracted and the tips were found rough and 
 denuded of peridental membrane. The right lower second 
 bicuspid, marked B, claimed attention, owing to the changed 
 bony area at the tip. This area, it will be noted, was much more 
 obvious than the area around the molar marked A. There is 
 exostosis of the root, and the lacunae of the bone in the affected 
 area are very indistinct. The tooth was opened, disclosing a 
 living infected pulp, which was removed with the expectation 
 that the tooth and adjacent bony tissue would recover their 
 
 Fig. 312. — Healthy man, thirty-five years of age. Anterior root of ^ excised 
 through the bifurcation of the root and extracted. It had an abscess sac only 
 slightly smaller than that of Case 12. (Films made by Dr. Willis F. Manges.) 
 
 normal tone. This was especially probable from the fact that 
 the adjacent molar, marked C, the root canals of which had been 
 filled, had healed so satisfactorily about the canal tips. General 
 mouth hygiene and routine dentistry caused the rest of the mouth 
 to heal satisfactorily. 
 
 Case No. 22 (Fig. 312). This next case is that of a healthy 
 man of thirty-five years whose right lower molar, marked A , is 
 defective in the anterior root. This was excised in the usual 
 way from the bifurcation of the root up through the crown to 
 the grinding surface. The membrane was thickened on the end 
 of the extracted root to form a sac somewhat less than that in 
 Case 12. The posterior root was treated and filled, and later 
 
372 MODERN DENTISTRY 
 
 formed an excellent abutment for a bridge. It will be noticed 
 that the two lower incisors, marked C, have a much more readily 
 observable area of infection around their tips. Both of these 
 teeth were loose, although the teeth had no external signs of 
 decay and both pulps were ahve. The pulps in both were re- 
 moved, the canals steriHzed and filled, and in about six months 
 the teeth tightened and the mouth made a satisfactory recovery. 
 Case No. 23 (Fig. 313). In this case the two upper central 
 incisors had received a blow during a game of football. The 
 right upper central incisor became sensitive and began to dis- 
 color. The pulp was removed and the canals filled. With the 
 
 Fig. 313. — Case 23. Right upper central incisor given a blow during a game of 
 football, that caused the pulp to die. (Fibns made by Dr. Willis F. Manges.) 
 
 history and clinical facts at our disposal, the slight discoloration 
 at the tips, as shown by the plate, are significant, but it must 
 not be forgotten that such discolorations are apt to occur in this 
 region owing to the presence of the anterior palatal foramen, 
 and therefore it is probable that the x-ray by itself would not 
 give rehable evidence. A soft tube will differentiate soft tissues 
 more than a hard tube, but, after aU, we must remember that the 
 x-iSiy of the mouth usually only gives information concerning 
 the hard tissues, while the inflammation may be largely confined 
 to the soft tissues. Still a careful examination of the right upper 
 central will show an interesting area of darkening. 
 
STUDY OF GUMS AND ROOTS BY THE X-RA.Y 
 
 373 
 
 
 2Q 
 
 s -^ 
 -a g 
 
 11 
 
 S.2 
 
 
 
 
374 MODERN DENTISTRY 
 
 Case No. 24 (Fig. 314) is that of the mouth of a young woman 
 of twenty-five years who has suffered intense neuralgic pains 
 for over two years. These pains were in both jaws, the left ear, 
 and radiated down the left shoulder and arm to the first and 
 second fingers. So desperate was her condition and so obstinate 
 her case that it seemed a true case of central trifacial neuralgia. 
 Her doctor, a diagnostician of wide reputation, was unable to 
 find anything wrong with her organs or general system. Her 
 ears were pronounced normal by a specialist, and finally she 
 was sent to have an x-ray taken of her mouth and teeth, and the 
 
 Fig. 315. — Case 24. A represents pulp stone, actual size, taken from molar 
 
 marked A. 
 
 author was requested to examine her mouth for possible sources 
 of trouble. A cursory examination of the x-ray plates seemed to 
 show an unusually healthy condition of membranes and bone 
 around the tips of all the teeth. But a more careful examination 
 of the right upper second molar, A , shows the presence of a large 
 pulp stone within the pulp chamber. This tooth was excessively 
 sensitive to the application of heat. The pulp was anesthetized 
 and removed, and Fig. 315 shows the photograph, actual size, 
 of the pulp stone that was removed from the pulp. It does not 
 appear as large in the x-ray plate as in the photograph, since it 
 was foreshortened, lying in the tooth in the line of the ray. 
 
STUDY OF ROOTS AND GUMS BY THE X-RAY 375 
 
 The lower right first molar, B, gave excessive response to the 
 application of heat, and its pulp was removed. It contained a 
 large infiltration of calcic salts. The left upper canine, C, also 
 had a congested infected pulp that was removed. These three 
 teeth were treated in one day, the intense neuralgic pain was 
 accentuated for twenty-four hours, and the next day disappeared 
 permanently. 
 
 The intense pain being removed, other teeth began to give 
 local manifestations, and the upper first and second right bicus- 
 pids revealed partly necrotic and dead pulps. These were re- 
 moved and the teeth treated. The upper left second bicuspid 
 was found infected and inflamed under a cement filling, and the 
 upper right molar revealed an aching pulp from which five small 
 pulp stones were removed, and the canals finally cleansed and 
 treated. 
 
 This procedure caused almost complete alleviation of the 
 suffering. The arm is steadily improving, and under the vaccine 
 treatment, supplemented by obvious dental work, there is every 
 reason to believe that her relief will be permanent. This case 
 particularly shows the value as well as the limitations of the 
 x-ray. 
 
 It will be noted that the most serious conditions are by no 
 means shown by obvious signs, and that the most threatening 
 changes may be rather the beginning of infection than the actual 
 infection itself. And yet there is the ink-black area associated 
 with hereditary syphilis that certainly demands surgical inter- 
 ference. 
 
 In the light of these varied degrees of shadow, the contra- 
 dictory significance of the shadows and the absence of shadow, 
 we must repeat that although the a;-ray is invaluable as one of 
 the means of diagnosis, it is not in itself always conclusive, and 
 should be supplemented by all the clinical confirmatory evidence 
 possible if the threatening beginnings of infection are not to be 
 overestimated, and the dangerous, faintly defined areas of in- 
 fection are not going to be altogether overlooked. 
 
INDEX 
 
 Abrasives in dentifrices, injury from, 
 
 60 
 Abscess, alveolar, 109 
 treatment, no 
 self-perpetuating, of mouth infection 
 20 
 Abutments, divergent, in bridge work, 
 
 292 
 Acid calcium phosphate solution, effect 
 of, on enamel, 44 
 sodium phosphate solution, effect of, 
 on enamel, 44 
 Acids, fruit, effect of, on enamel, 53 
 
 protective power of saliva against, 
 46 
 protective power of saliva against, 44- 
 Active immunization, 86 
 Adhesion of cements, 320 
 All-gold and porcelain bridge 303 
 Alveolar abscess, 109 , 
 
 treatment, no 
 Amalgam as cement, 187 
 crown with porcelain facing, 267 
 fillings, 186 
 
 method of making, 190 
 for attaching facings, 188 
 for repairing broken roots, 1 88 
 for restoration of crown, 189 
 for retaining inlays, 185 
 uses of, 185 
 Amboceptor, 87 
 
 Ameba buccalis in mouth infection, 108 
 Ames cement slab, 308 
 Amputation of roots, x-ray examination 
 
 before, 137 
 Anaphylaxis, 88 
 Anchorage, Baker, for orthodontia, 222- 
 
 225 
 Anemia and vaccine treatment, 106 
 24 
 
 Anesthesia, local, infiltration of gums in, 
 114 
 
 nerve-blocking in, 114 
 
 Ringer's solution for, in 
 
 syringe for, t 13 
 pressure, 117 
 
 disadvantages, 119 
 Angle appliances for orthodontia, 223 
 Antigen, 87 
 
 Antiseptics as mouth-washes, 57 
 Arch, expansion, Fauchard's, 208 
 Attached bridge, 282 
 Author's method for ascertaining proper 
 
 vaccine dose, 105 
 Autogenous vaccines, 91 
 
 advantages, 92 
 
 germs used for, 96 
 
 Bacilli used for autogenous vaccines, 96 
 
 for stock vaccines, 97 
 Bacillus influenzae, 96 
 Baker anchorage for orthodontia, 222- 
 
 225 
 Baking fillings, 1 74 
 Band crown, 272 
 Beutelrock driUs, 122, 123 
 Bifluorid of ammonium in tartar re- 
 moval, 81 
 Bleaching after removal of dental pulp, 
 
 133 
 Blood, bactericidal power of, in mouth 
 infection, 56 
 
 examination, in mouth infection, 67 
 Bone drills, 143 
 Bridge, attached, 282 
 
 double clasp, 298 
 
 inlay cantilever, 285 
 
 porcelain and all-gold, 303 
 
 removable, 290 
 
 377 
 
378 INDEX 
 
 Bridge work, attention to, in mouth in- 
 fection, 76 
 divergent abutments in, 292 
 gold clasps in, 290 
 Broken roots, repair of, with amalgam, 
 
 188 
 Brush, tooth-, proper selection of, 28 
 
 Calahan method of treating root canals, 
 
 126 
 Calcium phosphate, acid, solution, effect 
 
 of, on enamel, 44 
 Canals, root, Calahan method of treat- 
 ing, 126 
 emetin for treating, 128 
 exploring for, Flagg's technic, 131 
 filling of, 1 24 
 preparation of, 122 
 steriUzation of, 1 24 
 treatment, ioq 
 variations, 128 
 Cantilever bridge, inlay, 285 
 Cautery, electric, in diagnosis of mouth 
 
 infection, 69 
 Cement, adhesion of, 320 
 amalgam used for, 187 
 as inlaj' bond, 327 
 experiments with, 307 
 line, solubility of , 3 2 7 
 
 tests on, 310 
 phosphate of zinc, 309 
 siHcious, 307 
 
 mixing of, 307 
 slab for mixing, 308 
 Children, fractured teeth in, treatment, 
 204 
 orthodontia in, for general practi- 
 tioner, 207 
 proper time for, 209 
 Children's teeth and gums, care of, 197 
 Citric acid in mouth infection, 100 
 Clasp bridge, double, 298 
 Cleansing mouth, 26. See also Month 
 
 cleansing. 
 Cocain, dangers from, 113 
 Color selection of fillings, 170 
 Complement, 87 
 Crowns, 258 
 
 Crowns, amalgam, with porcelain facing, 
 
 267 
 band, 272 
 inlay, 268 
 pin, 260 
 
 method of making, 263 
 restoration with amalgam, 189 
 setting, gutta-percha for, 192 
 varieties, 258 
 work, attention to, in mouth infection, 
 
 75 
 
 Dental pulp, 109 
 
 indications for removal, no 
 removal of, 120 
 bleaching after, 133 
 Dentifrices, 56 
 
 abrasives in, injury from, 60 
 
 destructive action of, 60 
 
 magnesium peroxid, 59, 62 
 
 relation to mouth hygiene, 43 
 
 sodium perborate, 62 
 
 tests for loss of tooth substance from, 
 61 
 Dentistry, operative efficiency in, 150 
 Dentition, faulty, from malnutrition, 
 
 treatment, 252 
 Discoloration of teeth, 133 
 Divergent abutments in bridge work, 292 
 Double clasp bridge, 298 
 Drills, Beutelrock, 122, 123 
 
 bone, 143 
 
 Ear, infection of, relation to mouth in- 
 fection, 23 
 Electric cautery for diagnosis of mouth 
 infection, 69 
 furnace, 179 
 Electrolysis test for mouth infection, 71 
 Emetin for treating root canals, 128 
 in treatment of pyorrhea alveolaris, 
 108 
 Enamel, effect of acid sodium phosphate 
 on, 44 
 of fruit acids on, 53 
 of lactic acid solution on, 43 
 hardening of, 43 
 softening of, 43 
 
INDEX 
 
 379 
 
 Enamel, study of, 43 
 
 tests with living saliva, 51-53 
 microdynamometer, 46-54 
 
 Excision of roots, 142 
 
 Expansion arch, Fauchard's, 208 
 
 Exposed pulp, treatment of, in tem- 
 porary teeth, 203 
 
 Extirpation of frenum of lip in ortho- 
 dontia, 239 
 
 Extraction of teeth in mouth infection, 
 limitations of, 66 
 
 Eye, inflammation of, relation to mouth 
 infection, 24 
 
 Fauchard's expansion arch, 208 
 Filling of root canals, 124 
 Fillings, 150 
 amalgam, 186 
 
 method of making, 190 
 baking of, 1 74 
 color selection of, 1 70 
 for temporary teeth, 202 
 gutta-percha, 192 
 hammered gold, 151 
 making of, 1 74 
 plastic, 184 
 porcelain inlays, 154 
 Flagg's technic in exploring for root 
 
 canals, 131 
 Floss-silk, functions, 27 
 importance of use, 27 
 method of using, 31 
 Force required in mastication, 54 
 
 gnathodynamometer for measur- 
 ing, 55, 56 
 Fractured teeth in children, treatment, 
 
 204 
 Frenum of lip, extirpation of, in ortho- 
 dontia, 239 
 Fruit acids, effect of, on enamel, 53 
 
 protective power of saliva against, 46 
 Furnace, electric, 179 
 
 Gnathodynamometer for estimating 
 
 force in mastication, 55, 56 
 Gold clasps in bridge work, 290 
 
 fillings, hammered, 151 
 
 inlays, 179 
 
 Gram-negative coccobacillus in vaccine, 
 
 102 
 Gum infiltration in local anesthesia, 114 
 
 lancing in infants, theory of, 195 
 Gums of children, care of, 197 
 
 unhealthy, effect of vigorous brushing 
 on, 29 
 
 a;-ray examination of, 335 
 Gutta-percha as cement for inlays, 192 
 
 as filling, 192 
 
 for setting crowns, 192 
 
 properties of, 194 
 
 uses of, 192 
 
 Hammer, automatic, for diagnosis of 
 
 mouth infection, 71 
 Hammered gold fillings, 151 
 Hammond electric furnace, 179 
 Haptophore, 87 
 Hardening of enamel, 43 
 Hydrogen peroxid for bleaching, 134 
 solution as mouth-wash, 64 
 effects of, on bacteria, 58 
 
 Immunization, active, 86 
 
 passive, 86 
 Impaction of teeth, treatment, 242 
 Infants, gum lancing in, theory of, 195 
 Infected roots, excision of, 109 
 Infection, mouth, 17 See also Mouth 
 
 infection . 
 Infiltration of gums in local anesthesia, 
 
 114 
 Inlay bond, cement for, 327 
 
 cantilever bridge, 285 
 
 crowns, 268 
 
 matrix, porcelain, 161 
 Inlays, gold, 179 
 
 gutta-percha as cement for, 192 
 
 porcelain, 154 
 
 construction of, 162 
 insertion of, 176 
 cautions in, 1 76 
 
 retention of, with amalgam, t8.<; 
 Ionization test for mouth infection, 71 
 
 Lactic acid solution, effect of, on enamel, 
 43 
 
38o 
 
 INDEX 
 
 Lancing gums in infants, theory of, 
 
 195 
 Lip, extirpation of frenum, in ortho- 
 dontia, 239 
 Local anesthesia, infiltration of gums in, 
 114 
 nerve-blocking in, 114 
 Ringer's solution for, iii 
 syringe for, 113 
 Logan-Buckley scalers, 81 
 Lost teeth, replacement of, 282 
 
 Magnesium peroxid as dentifrice, 59, 62 
 
 Making fillings, 174 
 
 Malnutrition, faulty dentition from, 
 
 treatment, 252 
 Mastication, force required in, 54 
 Matrix, porcelain inlay, 161 
 Membrane, peridental, tooth nutrition 
 
 by, 121 
 Micrococcus catarrhalis, 97 
 Microdynamometer, 47, 48, 50 
 
 tests of enamel, 46-54 
 Mouth cleansing, 26 
 dentifrices for, 56 
 floss-silk in, 31-34 
 methods, 26 
 mouth- washes for, 56 
 relation of dentifrices to, 43 
 
 of mouth-washes to, 43 
 tooth-brushing for, 28, 34-40 
 infection, 17 
 
 Ameba buccalis in, 108 
 attention to bridge work in, 76 
 
 to crown work in, 75 
 bactericidal power of blood in, 56 
 blood examination in, 67 
 causes, 17 
 citric acid in, 100 
 course of, 20 
 diagnosis, 65 
 
 by electrolysis, 71 
 general, 65 
 local, 67 
 
 with automatic hammer, 70 
 with electric cautery, 69 
 effects, 17, 23 
 electrolysis test for, 71 
 
 Mouth infection, emetin in, 108 
 examination of teeth in, 68, 76 
 genera] causes, 19 
 
 physical examination in, 67 
 germs commonly obtained in, 95 
 ionization test for, 71 
 local causes, 21 
 osteoarthritis in, vaccine treatment, 
 
 106 
 prevention of, 26 
 relation of internal ear infection to, 
 
 23 
 of ocular disease to, 24 
 of salivary gland infection to, 
 
 23 
 
 of spinal irritation to, 24 
 
 of tonsillar disease to, 23 
 removal of foci in dental work, 77 
 restoring normal occlusion in, 77 
 self-perpetuating abscess of, 20 
 Streptococcus viridans in, 22 
 tooth extraction in, limitations of, 
 
 66 
 treatment, 65 
 
 emetin, 108 
 
 local, 75 
 
 of loose teeth in, 78 
 
 of pus pockets in, 100 
 
 specific, 79 
 
 vaccine, 85 
 
 cautions in, 90 
 urine examination in, 67 
 vaccine treatment, 85 
 
 cautions to observe, 90 
 violet-ray in, 74 
 
 with tuberculosis, treatment, 100 
 a;-ray examination in, 78 
 restoring, proper approximation in, 
 
 77 
 Mouth-washes, 56 
 antiseptic, 57 
 
 peroxid of hydrogen solution, 40, 64 
 relation of, to mouth hygiene, 43 
 sodium silicofluorid solution, 40, 64 
 
 Necrotic roots, excision of, 109 
 Nerve-blocking in local anesthesia, 114 
 Novocain, advantage of non-toxicity, 1 13 
 
INDEX 
 
 381 
 
 Novocain-suprarenin solution for local 
 anesthesia, no 
 
 Nutrition, tooth, by peridental mem- 
 brane, 121 
 
 Orthodontia, Angle appliances for, 
 223 
 Baker anchorage for, 222-225 
 extirpation of frenum of lip in, 239 
 in children for general practitioner, 
 207 
 proper time for, 209 
 Osteoarthritis, mouth infection in, vac- 
 cine treatment, 106 
 Oxalic acid for bleaching, 134 
 
 Parent germs, obtaining of, for vac- 
 cines, 93 
 Passive immunization, 86 
 Perborate of sodium as dentifrice, 62 
 Peridental membrane, tooth nutrition 
 
 by, 121 
 Peroxid of hydrogen for bleaching, 134 
 solution as mouth-wash, 40, 64 
 effect of, on bacteria, 58 
 of magnesium as dentifrice, 59, 62 
 Phosphate of zinc cements, 309 
 Pin crown, 260 
 
 method of making, 263 
 Plastic fillings, 184 
 Pneumococcus capsulatus, 98 
 Porcelain and all-gold bridge, 303 
 inlay matrix, 161 
 inlays, 154 
 
 construction of, 162 
 insertion of, 176 
 cautions in, 176 
 strength of, 155 
 tests for, 157 
 Pressure anesthesia, 117 
 disadvantages, 119 
 Pulp, dental, 109 
 functions of, 76 
 removal of, 120 
 bleaching after, 133 
 indications for, no 
 exposed, treatment of, in temporary 
 teeth, 203 
 
 Pus pockets, treatment of, in mouth in- 
 fection, 100 
 
 Pyorrhea alveolaris, emetin treatment, 
 108 
 
 Removable bridge, 290 
 
 Ringer's solution for local anesthesia, 
 
 III 
 Roentgen ray. See X-ray. 
 Root canals, Calahan method of treating, 
 126 
 emetin for treating, 1 28 
 exploring for, Flagg's technic, 131 
 filling of, 124 
 preparation of, 122 
 steriUzation of, 1 24 
 treatment, 109 
 variation, 128 
 Roots, amputation of, ar-ray examination 
 before, 137 
 broken, repair of, with amalgam, 188 
 excision of, 142 
 
 infected or necrotic, excision of, 109 
 x-ray examination of, 335 
 
 Saliva, living, enamel tests with, 51 
 protective power of, against acids, 44 
 
 fruit acids, 46 
 study of, 43 
 
 Salivary gland infection, relation of, to 
 mouth infection, 23 
 
 Scalers, tartar, 80, 81, 82 
 
 Self-perpetuating abscess of mouth in- 
 fection, 20 
 
 Sensitization, 89 
 
 Sensitized vaccines, 98 
 
 Silicious cements, 307 
 mixing of, 307 
 
 Slab for mixing cement, 308 
 
 Smith scalers, 82 
 
 Sodium perborate as dentifrice, 62 
 phosphate, acid, solution, effect of, on 
 
 enamel, 44 
 silicofluorid solution as mouth-wash, 
 40, 64 
 
 Softening of enamel, 44 
 
 Solubility of cement line, 327 
 
 Solvent, tartar, 80 
 
382 
 
 INDEX 
 
 Spine, irritation of, relation to mouth 
 
 infection, 24 
 Sterilization of root canals, 124 
 Stock vaccines, 91 
 advantages, 92 
 germs used for, 96 
 Streptococcus pyogenes, 95 
 
 viridans in mouth infection, 22 
 Syringe for local anesthesia, 113 
 
 Tartar, removal of, in mouth infection, 
 
 79 
 
 with bifluorid of ammonium in, 81 
 scalers, 80, 81, 82 
 solvent, 80 
 Teeth, cleaning of, 26. See also Moidh 
 
 cleansing. 
 examination of, in mouth infection, 
 
 68, 76 
 fractured, in children, treatment, 204 
 gums, x-x3t.y examination, 335 
 impaction of, treatment, 242 
 loose, treatment of, in mouth infection, 
 
 78 
 lost, replacement of, 282 
 of children, care of, 195 
 roots, x-xdiY examination, 335 
 temporary, fillings for, 202 
 
 treatment of exposed pulp in, 203 
 Test, electrolysis, for mouth infection, 
 
 71 
 
 for loss of tooth substance from denti- 
 frices, 61 
 
 ionization, for mouth infection, 71 
 
 of enamel with living saliva, 51-53 
 
 with microdynamometer, 46-54 
 
 Tonsils, disease of, relation to mouth 
 
 infection, 23 
 Tooth discoloration, 133 
 
 enamel. See Enamel. 
 
 extraction in mouth infection, limita- 
 tions of, 66 
 
 nutrition by peridental membrane, 
 121 
 
 pulp, functions, 76 
 
 Tooth substance, tests for loss of, from 
 dentifrices, 61 
 
 Tooth-brush, proper, selection of, 28 
 
 Tooth-brushing, 28 
 
 effect of, on unhealthy gums, 29 
 proper method, 34-40 
 
 Toxophore, 87 
 
 Tubercle bacilli in vaccines, 102 
 
 Tuberculosis complicating mouth infec- 
 tion, treatment, 100 
 
 Urine examination in mouth infection, 
 67 
 
 Vaccination, theory of, 85 
 Vaccine treatment of mouth infection, 85 
 cautions to observe, 90 
 with osteoarthritis, 106 
 Vaccines, autogenous, 91 
 advantages, 92 
 germs used for, 96 
 dosage, 100 
 
 author's method for ascertaining, 
 
 105 
 Gram-negative coccobacillus in, 102 
 in anemia, 106 
 
 obtaining parent germs for, 93 
 preparation of, 90 
 sensitized, 98 
 stock, 91 
 
 advantages, 92 
 
 germs used for, 97 
 symptoms of reaction in, loi 
 tubercle bacillus in, 102 
 Violet-ray in mouth infection, 74 
 
 X-RAY examination in mouth infection, 
 78 
 of gums and roots, 335 
 of roots before amputation, 13 7 
 plates, interpretation of, 337 
 
 YuNGER scalers, 80 
 
 Zinc phosphate cements, 309 
 
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