Columbia UnibersJitp in tfje Citp of i^eto ^orfe ^cfjool of Bental anb (j^ral burger? l^itirarp Digitized by the Internet Archive in 2010 with funding from Open Knowledge Commons http://www.archive.org/details/dentalsciencequeOOinge Nev) York DENTAL SCIENCE; ^ Questions and Answers, Dentai- Materia Medica, De:ntal Physiology, Dental Pathology and THEKAPEinTCS; LUMAN C. INGERSOLL, A, M., D. D. S. Dean of the Dental Depaktjient oi THE State Univekbity oi" Iowa. R. B, OQDEN Si SON, PRINT , KEOKUK. 1386, Entered according to Act of Congress, in the year Eigliteen Hundred and Eighty-Six, by L. C. INGERSOLL, in the Office of the Librarian of Congress, at Wash- ington, D. C. DEDICATION. CO-ADJUTORS. WHO HAVE GIVEN TO ME SUCH GENEROUS AND AMPLE SUPPORT IN ALL MY WORK, THIS VOLUME IS MOST RESPECTFULLY INSCRIEEL BY THE AUTHOR. CHAPTER I. Dkntai, Materia Medica. CHAPTER H. Dental PmsioLocn- CHAPTER HI. Dkx'iai. Patholoc;^ and Tiieh apkutrs PREFACE. The tliree Chapters of this iJook are :i compendium f)f the Lectures ilehxered by the Author iu the Dental Department of the .State University of Iowa, As the Lectures were not intended to cover the ground of all our Dental Literature, the Compenchum, of necessity, must come far short of it. The purpose has heen simply to bring conspicuously into notice the fundamental facts and principles which underlie the practice of Dentistry. Having that in view, the Lec- tures were prepared from the stand-point of an otfice practice. In the Lectures I cracked many nuts; in the Compendium I have thrown away the shells and saved only the meats. 1 have adopted the catechetical style as the most di- rect mode of fixing attention upon the facts and pi'inciples to be learned, and as the most concise mode of formula- ting instruction. The blank pages will serve for taking notes of read- ing, or of information derived from other sources, on the same subjects as are made points of inquiry- on the page opposite. Thus the work becomes a LTand Book of Ready Reference for the Office. My object in putting Materia Medica first, in the order of subjects treated, is, that it is more easily com- prehended and learned bv the large class of students who go to a Dental College with their minds out of training for the close and connected thought required in the studv of Phvsiology and Pathologv. LUMAN C. INGERSOLL, July, 188(). Keokuk, Iowa. CHAPTER I. MATERIA MEDIC A, [MATERIA MEDICA broadly considered, is an embodi- ment of the History, Chemical Nature, Medicinal Prop- erties and Therapeutical action of all substances used in modern days as medicines. The United States Dispen- satory is designed to be such an embodiment. The use of Medicines should be reduced to the smallest number possible to secure the desired results. It is better to enter upon the practice of Dentistry with few medicines- such as have been tested by a long experience of the Dental Profession — than to try many new medicines with doubtful knowledge of their effects. Those here to be noticed are of the former class. New remedies should be experimented with only when the tried remedies either fail, are feebly effective, or are rendered objectioii^^ble by the idiosyncrasies of the patient.] GEORGil tVANS Of what does Materia Medica ti^^^t 39th St., N. Y. City, Ans. Of the properties of those substances which are used as medicines. How are medicines classified ? Ans. Accordinor to their effects. Name the different classes in common use bv dentists. Ans. Stimulants; Tonics; Sedatives; Narcotics; Refrigerants; Astringents; Styptics; : Caustics; escharotics; Antiseptics; Disinfectants; Laxatives; Anesthetics; ■ DENTAL MATERIA MEDIC A. In what ways are medicines used? Ans. Topically and generally. What is understood by a topical, and what by a g-eneral use of medicines? ^ ' Ans. Medicines are used topically, when applied to a local and circumscribed part; and generally, when used to affect the whole system. Which of the two methods is specially adapt- ed to Dental practice ? Ans. The topical. Are dental diseases local or general? Ans. Usually local; but local affection may produce general disease. In the latter case, which class of medicines should be used? Ans. Local, usually; for, removing the local cause, will in most cases relieve the general system. May general disease manifest itself locally in the Dental organs? Ans. Yes. Give an example. Ans. Malarial disease manifesting itself in facial neuralgia. What class of remedies is indicated in such a case? Ans. Both general and local. Local, to re- lieve the local pain, and general, to remove the cause. DENTAL MATERIA MEDICA. 9 Is it wise tor dentists to attempt to treat general disease? Ans. It is not; tiie larcrer experience of the ^ ^ • ^""^^^^ — general practitioner enables him to be more ''x. successful. STIMULANTS. Define. — Stimulants are medicines which ex- cite functional action, especially, the action of the vascular and nervous systems. Give the origin and primary signification of the word stimulant. Also its singular and plural forms, Ans. It is derived from the latin word stitnulare, to goad into action. Sing. Stimulus. PI. Stimuli. How are stimulants classified? Ans. A two fold classification, viz: 1st. Vascular and nerve stimulants; - 2nd. Diffusive, and persistent stimulants. What is a diffusive stimulant ? Ans. A stimulant prompt in action, but temporary in its effects. What is a persistent stimulant? Ans. One that is lasting in its effects, though pot always prompt in action. What are the most common stimuli in use by dentists? Ans. Capsicum, Oil of Cloves, Creasote, Heat and Cold, and the various vegetable oils. 10 DEN TAL MATERIA MEDICA. Which of the stimuH named is both the most prompt and the most persistent ? Ans. Capsicum. Capsicum. — Describe. Ans. A yellowish-red vegetable powder — has a sharp, pungent, bitterish taste, with a sense of burnino- over the whole mouth. o What is its solubility ? Ans. Slightly soluble in water and vinegar; very soluble in alcohol and ether. What preparations are usually found in the shops. Ans. The extract and the tincture. Why is Capsicum peculiarly adapted to local use ? Ans. Because it is prompt and persistent in action and will not vesicate, unless confined. In what diseased conditions is it specially indicated ? Ans. In chronic inllammations, in indura- tions, in peridental inllammation, and in cases of incipient abscess. In what combination is it used as a general pain obtundent ? Ans. In combination with Chloroform and Tinct. of Aconite, equal parts. In such combination should it be applied ex- ternally, as a compress ? DENTAL MATKKIA MKDICA. H Ans. It should not, unless the object is to vesicate. It should be applied on a ball of cotton moved lightly over the affected part. Oil of Cloves. — Give a description of this Oil. Ans. It is an aromatic oil distilled from cloves; is very Muid, clear and colorless; be- comes yellowish by exposure, and finally of a reddish brown color. What are its common adulterations, and what the tests of its purity? Ans. Adulterated with other essential oils. Its specific gravity being greater than that of water, when water is added the oil of cloves will be found at the bottom of the bottle, ex- cept when adultered with the oil of Cinnamon, which is also heavier than water. What are the two most prominent and im- portant elements contained in this oil? Ans. An aromatic and pungent oil, and Tannin, in equal proportions. What are its effects? Ans. A prompt and active stimulant and astrinaent. What is its use in dentistry? Ans. To quiet the pain of an exposed pulp; peculiarly adapted to children's teeth, and all cases of demineralized dentine. Is it antiseptic? 12 DENTAL MATERIA MEDICA. Ans, In small degree only; but having stim- ulating and astringent properties it is indicated in all cases of ulceration, superficial and deep seated, Creasote. — Give a description of its appear- ance and properties? Ans. Pure Creasote is a distillation from wood tar, of which it retains the odor; it is a nearly colorless oil; a stimulant prompt in ac- tion, creating a sharp stinging and burning sense in the mouth; promotes an active circula- tion in the parts with which it comes in con- tact; combined with Oil of Cloves, equal parts, it is one of the most valuable pain obtundents in use for cases of exposed pulp. [More fully treated of under the head of Antiseptics.] Heat and Cold. — What is the effect on the tissues when heat is applied ? Ans. Heat expands the blood vessels and increases the circulation. What is the effect of cold? Ans. Cold contracts the vessels, and de- creases the circulation; also decreases the heat of an inflamed part. What is the effect of heat in cases of acute inflammation of a pulp ? Ans. Moderate heat increases the pain, intense heat relieves it. DENTAL MATKKIA MKDICA. 1;-^ What is the (effect of cold on the same condition? Ans. It increases the pain. What is the effect of cold in a case of chronic inflammation? Ans. It relieves it. What is the special use of ice coldness? Ans. Ice is used to prevent an alveolar abscess from pointing externally upon the face. What is the best method of applying- cold water for the relief of an achine tooth^ Ans. With a napkin, externally. In cases of chronic inflammation of the root membrane, what is the best method of employ- inor heat ? Ans. By a hot foot bath, and by the inter- nal use of hot ginger tea or other stimulating tea. In what way may you combine the effects of both heat and cold? Ans. By using heat at the feet and cold water on the face. How, and on what principle, may the stimula- ting effects of cold induce heat? Ans. By using intense cold; the effect being to excite vital re-action. Mention examples. Ans. A glow of heat and perspiration, induced by a copious draught of cold water; 14 DENTAL MATERIA MEDICA . a redness and warmth of the fingers when playing with the bare hands in snow. TiNCT. OF Iodine. — How obtained? Ans. Iodine is obtained from the ashes of sea- weed; is found in the shops in the form of flat purple- colored ciystals, with a metalic lustre, and as a tincture. How is it used in Dental practice? Ans. To promote absorption of superfluous growths and swellings, and also to allay inflam- mation of the alveolo-dental membrane, and to arrest abscess. Prep. — Tinct. 1 part, Iodine crystals, 12 parts by weight of alcohol . Aqueous Solution. — ^ oz. Iodide of Potas- sium, ^ oz. Iodine, 8 oz. warm water. First dissolve the I. P. Why are acqueous solutions preferable? Ans. Because water is more readily ab- sorbed by the gum than alcoholic preparations. TONICS.— Define. Ans. Tonics are medicines which by in- sensible degrees give healthful activity and vigor to the functions. To what class of medicines are the Tonics allied? Ans. To the Stimulants. What is the difference experimentally, be- tween a Stimulant and a Tonic? bENTAL MATKHIA MKDICA. lO Ans. A Stimulant produces a very prompt and sensible impression; a tonic produces an impression so mildly as to be scarcely sensibly felt. How would you use a Stimulant to produce a tonic effect? Ans. Reduce a stimulant until its effect is mild. What other tonics may be used beside the mild stimulants? Ans. Sulphate of Zinc, Tannin, Tea, Cam- phor, SuLPH. Zinc. — Describe. Ans. It is a transparent, colorless salt, crystalizing in 4 sided prisms, and having a disagreeable metalic taste. What is the character of the commercial article? Ans. It is impure and should never be used medicinally; it is know^n as white vitriol. What are the properties of Sulphate of Zinc? Ans. It is tonic, astringent, and in its full strength, caustic. Is it recommended in its caustic strength? Ans. It is not, because of the pain which it produces. What is the strength of the preparations recommended? l6 DENTAL MATERIA MEDtCA. Ans. One to five grains to the ounce of water. It is insoluble in alcohol. In what cases is Sulph. Zinc, specially indi- cated? Ans. In cases of chronic ulceration, not of a malignant character ; cases of debilitated function in a part. What is its action in reducing inflammation? Ans. By its astringency it contracts and de- pletes the blood vessels. What is its use in diseased conditions of the gum and contiguous parts? Ans. It is valuable in ulcerative conditions of the gum about the necks of the teeth and in peripyema. What is the peculiarity of this preparation which renders it well adapted to be used on the gum? Ans. Being an acqueous solution, it is more readily absorbed than alcoholic medicines. Tea. — Is tea a vascular or a nerve tonic? Ans. A nerve tonic. What two varieties of tea are usually found in the market, and how are they distinguished? Ans. Green and black; green tea has a leaf long and pointed, three times as long as it is broad; the leaf of black tea one-third shorter. What are the elements contained in tea? fc^i/kM^^-^^ DENTAL MATERIA MICIUCA. 17 Alls. A Volatile Oil, Tannic Acid, Theine, Albumen and a number of other elements of less importance. To which of these elements does it owe its stimulating and tonic effects? Ans. To its volatile oil and theine; especial- ly the latter. Which variety of tea possesses the most theine? Ans. Green tea; contains from 2 to 4 per. cent of theine: What is its taste? Ans. Astringent, aromatic and coolinp-. To what is its astringency due? Ans. To the element of tannin. What are its other properties? Ans. It is an antifebrile, removing the fe- verish condition of the mouth. It is a de- oderizer, and is in small degree antiseptic. When is its use specially indicated? Ans. After the extraction of teeth, to cor- rect all disacrreeable taste in the mouth, and to promote the healing of lacerated and in- llamed gums. How is it used? Ans. In a decoction two or three times as strong as that prepared for the table, and used cold instead of hot. 18 DENTAL MATERIA MEDICA. Camphor. — Describe. Camphor is a white, tenacious and translu- cent gum, with a pungent, penetrating and fra- grant odor; it is soluble in alcohol, acetic acid, chloroform and the fixed oils; alcohol forms a 75 per cent, solution. What are its properties ? Ans. Sedative, tonic, and gives a sense of coolness. What is its most direct action ? Ans. It acts primarily upon the nerves, and secondarily upon the vascular system, NARCOTICS AND SEDATIVES. What are Narcotics and Sedatives? Ans. Medicines vvhich allay irritability, re- lieve pain and promote sleep. What is the chief of the Narcotics used lo- cally ? . Ans. The preparations of Opium. Opium. — Describe. Ans. A gum obtained from the poppy plant; a very poisonous drug, producing sleep and death. In small and diffused quantities it is used as a Sedative, acting upon the nervous system. Laudanum. — What is it ,^ Ans. A tincture of opium. DENTAL MATKKIA MEDICA. 19 Prep. 1% oz. opium to 1 pint of equal parts of alcohol and water. What other preparation of opium is adapted to local use ? Ans. Wine of opium. Prep. — 2 oz. powdered opium, 75 grs. each of powdered cloves and powdered cinnamon, macerated in 1 pint Sherry wine for seven days, then filter. How is it affected by age? Ans. It loses its sedative effect, gradually. ' Which of these preparations is preferable? Ans. Wine of opium. How is sedation produced ? Ans. In two ways; sedation may be pro- duced mechanically, by removing the cause of irritation, as when air is excluded from an in- flamed pulp, or it may be produced fttnctionally by allaying the susceptibility of the nerves to the effect of an irritant. May stimulants produce a sedative effect ? Ans. They may as a secondary effect. What stimulants produce this secondary effect ? Ans. Alcohol, Chloroform, Creasote, Car- bolic acid, Tinct. of Aconite. TiNCT. OF Aconite. — What preparation is preferred ? 20 DENTAL MATERIA MEDIC A. Ans. That prepared from the root of the plant. What is the effect of the drug when taken internally ? Ans. It is a powerful and active poison. What is the effect applied externally ? Ans. Its first effect is stimulant, its second- ary effect, sedative . Name two preparations valuable as a lini- ment in neuralgic affections? Ans. 1. Equal parts of Tinct. of Aconite and wine of Opium. 2. Equal parts Tinct. of Aconite. x\lcohol and Chloroform. Which of these is safest to be applied as a local anaesthetic in the mouth? Ans. The latter. REFRIGERANTS. What are Refrigerants ? Ans. Medicines which reduce heat and give a cooling sensation. What are those best adapted to dental use externally ? Ans. Ice and cold water; to theVater may be added an equal quantity of alcohol or vine- gar with cooling effect. What may be used with good effect inter- nally ? DENTAI, MATKRIA MKOrCA. 21 Ans. Chlorate of Potash, lemon juice di- luted, and other mild acid drinks and acid fruits. ASTRINGENTS. What are Astringrents ? Ans. Medicines which contract the tissues to which they are applied, and co-agulate albu- menous substances. What is the chief element in all vec^etable astringrents ? Ans. Tannin. From what is tannin usually obtained ? Ans. Nuto-alls. Name the per cent, of tannin in the different veg-etable substances in use as medicines. Ans. Nutgalls, 52 to 80 per cent. Kino, 57 Catechu 32 to 50 Oak Bark 11 Black Tea 13 Green Tea 16 Blackberry Root ; 9 Describe the appearance of Tannin. Ans. It is a very light , flaky powder, of a yellowish color. What is its solubility ? Ans. It is soluble in water, alcohol and ether. 22 DENTAL MATERIA MEDICA. How is it best preserved ? Ans. In the powder; in solution it is liable to deteriorate. (See Styptics.) STYPTICS. What are Styptics ? Ans. Medicines which tend to arrest hem- orrhage. How is the arrest of hemorrhage accom- plished ? Ans. In three ways. By co-agulating the blood at the mouths of the bleeding vessels, — by contracting the vessels, — and by compres- sion, artificially. What is the effect of the atmosphere on fresh blood ? Ans. It co-agulates it. What is co-agulation of blood ? Ans. It is a thickening of the fibrin of the blood into a glutenous clot. Is all blood alike co-aeuable ? Ans. It is not. Why? Ans. All blood has not the same relative amount of fibrin. Upon what class of medicines do we rely for the styptic effect ? Ans. Astringents; all the vegetable and mineral astringents. DteNTAL MATERIA MfiDICA. 2'6 Name the three in most common use by dentists. Ans. Tannin, alum, per-sulphate of iron, and the concentrated extract of hamamehs. How applied? Ans. The first two should be used in the dry state, but may be used in solution. Of the three styptics named, which is the most powerful ? Ans. Per-sulphate of Iron. Describe it. Ans. It is a reddish-brown, heavy powder, a powerful astringent and mild caustic. Which is preferable for dental use, the powder, or Monsel's solution ? Ans. The powder. What is the method of arresting- severe hemorrhaore occurinor after extraction of teeth? Ans. By the use of per-sulphate of Iron. Take a pellet of cotton or sponge, little larger than a pin's head, moisten with water and pass it into the open socket to the very bottom, holding it there for a moment to allow time for a firm coagulum to form, then gently remove the instrument. What constitutional peculiarity indicates the use of compression ? Ans. The hemorrhao^ic diathesis. In case of such patients secondary hemorrhage is 24 DENTAL MATERIA MEDtCA . liable to occur, when compression is indi- cated. Fill the socket loosely with cotton, covered with tannin or powdered alum, then form a pad of linen cloth, covering- one sur- face with tannin, bring the jaws together upon the pad, and bandage over the head and under the chin. CAUSTICS.— Define. Ans. Caustics are medicines which create a sense of burning, and devitalize animal tissue superficially. For what purpose are Caustics used ? Ans. Caustics are used in all cases of chronic ulceration, cases of superfluous growth, and in treatment of alveolar abscess. For what direct purpose are caustics used In treatment of abscess? Ans. To devitalize the abnormal tissue formed about the apical portion of a tooth root. Name the caustics in most common use by dentists. Ans. Carbolic Acid, Iodine, Chloroform, and Iodine combined with Creasote, equal parts. ESCHAROTICS.— Define . Ans. Escharotics are medicines that pene- trate the surface, burning and devitalizing the tissue deep and producing an eschar. How is the escharotic effect usually checked ? DENIAL MATKKIA JMEDICA, 25 Ans. Its strength is lost by dilution in the tissues. Why are escharotics so seldom used by dentists ? Ans. Because of the pain they produce, and the difficulty of arresting their action at the proper time. How may a caustic be used with escharotic effect ? Ans. By repeated applications. Which of the caustics named is preferable for this purpose ? Ans. Carbolic Acid. Name a few escharotics in use by dentist. Ans. Chloride of Zinc, Sulphate of Zinc, Potash, Arsenic. ANTISEPTICS.— Define. Ans. Medicines which prevent putrefaction. What antiseptic substances are in common use for culinary purposes ? Ans. Salt, sugar, spices, vinegar, alcohol, What drugs are in general use by dentists for their antiseptic effect ? Ans. Creasote, carbolic acid, phenol-sodique salicylic acid, iodoform, alcohol, eucalyptus oil. These are the chief. Creasote and Carb. Acid. — How are they distinguished, the one from the other ? 26 DENTAL MATERIA MEDICA. Ans. 1st. By the sources from which they are derived; the former being- a distillation from wood tar, and the latter from coal tar. 2nd. By their chemical relations; Creasote be- ing" an oil, and Carbolic Acid an alcohol; Creasote being a liquid non-crystalizable, and Carbolic Acid always, in its pure state, crys- talizable; Creasote is not soluble in water, and Carbolic Acid is readily soluble in 5 per cent, of water, and in any proportions by the ad- dition of glycerine. 3d. By their difference of medicinal properties; pure wood Creasote is not a caustic; carbolic acid is a powerful caustic; Creasote is not a germicide; Carbolic Acid is a prompt germicide for most micro- organisms. Phenol Sodique. — What is this drug. Ans. It is formed by the action of caustic soda on impure carbolic acid. What impurities are combined ? Ans. Cresylic and Picric Acids; both good antiseptics and not objectionable in the combi- nation. It derives its name from Phenol, the name formerly given to crude carbolic acid. What are its uses ? Ans. The same as Creasote. Salicylic Acid. — Describe. Ans. It is a white, light, feathery powder, DENTAL MATERIA MEDICA. 27 having a slightly sweetish taste, afterwards stinging. What are its solvents ? Ans. Alcohol, ether, glycerine and hot water. Alcohol dissolves it freely; cold water sparingly. The alcoholic solution is an excel- lent dressing for root canals previous to filling. Iodoform. — Describe. Ans. It is in the form of small, pe.arly, yel- low crystals, volatile and of a disagreeable odor, which may be disguised by combination with Oil of Cloves or Eucalyptus Oil or both. How is it obtained ? Ans. It is a preparation of Iodine obtained from the alcoholic solution of Iodide of Potassa. What are its solvents ? Ans. It is soluble in alcohol, chloroform, ether and the volatile oils, but insoluble in water. What are its properties and uses? Ans. It is stimulant, anaesthetic, tonic; a valuable antiseptic and sedative for suppurating surfaces; it is of the nature of a specific in treatment of teeth in which the pulps have died spontaneously; it promotes cicatrization; it is valuable combined with chloroform so- lution of gutta percha and the oxi-chloride of zinc for filling root canals; although it contains 75 per cent, of Iodine, it is non-irritant. 28 DENTAL MATERIA MEDICA. Eucalyptus Oil. — A distillation from the leaves of the Eucalyptus tree. What are its properties? Ans. It is an aromatic sedative and good antiseptic. Combined with Iodoform it is highly jecommended in treatment of suppurating pulps and incipient abscess, also in treatment of caries of the alveolar processes, and in necrosis, DISINFECTANTS AND GERMICIDES — Define. Ans. Disinfectants are medicines which deodorize, nutralize and sterelize the products of decomposition and putrefaction . Germicides are medicines which destroy the micro-organisms concomitant with putrefactive decomposition. Name those best known in dental practice y Ans. Carbolic Acid, Chloride of Zinc, Sul- phate of Iron, Permanganate of Potassa, Per- oxide of Hydrogen, Bi-chloride of Mercury, Aromatic Sulp. Acid. Carbolic Acid. — Long considered the best disinfectant known; although active as a disin- fectant, it is found that all the products and concomitants of putrefaction are not destroyed by it, which is probably true of every drug in use for disinfecting purposes. (See Anti- septics.) DKNTAL MATERIA JVIEDICA. 29 Chloride of Zinc. — Formed by the action of hydro-chloric acid on metahc zinc. What are its properties? Ans, Physically, it is a white, crystaline mass, readily deliquescent on exposure to the atmosphere, and wholly soluble in water, when pure. Medicinally, it is an escharotic, astrin- gent and powerful disinfectant. Used as an escharotic it causes severe pain. What are its uses in the mouth? Ans. It is used in phagedenic ulceration of the gums, peripyema, caries of the alveolar process and necrosis. Prep. — 2 to 10 grains to the fluid ounce of water. It is also valuable in the roots of teeth where putrescent matter is found. Sulphate of Iron. — Copperas; dissolved in twice its weight of cold water; or three fourths its weight of hot water, is used to cleanse spittoons, slop pails and sinks. Permanganate of Potassa. — How obtained? Ans. By the action of manganic acid upon caustic potash. It forms in long blue-black quadrangular or prysmatic crystals. What is its solubility? Ans. It is freely dissolved in water; it is used in solution of from 5 to 20 parts, by weight, to 100 of water. It is most conve- 30 DENTAL MATERIA MEt)ICA . nient to form a 20 per cent, solution as a stan- dard of strength, then reduce as needed. What are its properties ? Ans. It is one of the most powerful disin- fectants known; has extraordinary power in destroying fetid odor from organic sources, poisonous emanations from gangrenous ulcers, abscesses and wounds of all kinds. As an oxidizer it is not second to per-oxide of hydro- gen. It is valuable in treatment of deep seated ulceration, caries of bone and necrosis, Per-oxide of Hydrogen. — Of what does it consist ? Ans. It consists of water with an additional equivalent of oxygen, united in the nascent state . What are its properties ? ' Ans. It is a powerful oxidizer, freely part- ing with its oxygen at the temperature of 60°, hence should be kept in close stoppered bottle in a cool place. What restrains and what promotes its action? Ans. Tobacco, aconite and other narcotic substances restrain its action, and contact with platinum or gold increases the activity with which its oxygen is liberated, hence it can be applied most effectively with a gold or platinum instrument. DENTAL MATEltIA MEDICA. 31 Bi -CHLORIDE OF Mercury. — Corvosive Subli- mate. What are its properties and uses? Ans. It is stimulant, antiseptic, disinfectant and a powerful germicide. In a strong prep- aration it is a danorerous escharotic. It is used chieHy as a germicide. What is the preparation for common use in ulceration and in treatment of peripyema i^pyorrhcea alveolaris}) Ans. 1 gr. Bichloride of Mercury and 40 drops of alcohol to 3 fluid ounces of water. Aromatic Sulphuric Acid. — What are its properties ? Ans. In full strength it is mildly caustic and a good disinfectant, causing some pain . It is astringent, and in its milder solutions is stimu- lant and tonic. What are its uses ? Ans, It is used in cases of peripyema, caries of bone, and necrosis; also in cases of mercurial sore mouth and salivation. For ordinary treatment it should be reduced 50 per cent. LAXATIVES. Give the effect of medicines of this class ? Ans. Laxatives are mild cathartics, acting upon the bowels to promote a more free dis- charge.from the mucous lining of the intestines, 32 DENTAL MATERIA MEDICA. and to relieve costiveness by unloading the bowels, and increasing their peristaltic action. How are laxatives employed in dental practice ? Ans. Both as medicines and diet. What medicines are used ? Ans. The saline cathm^tics^ such as solution of Citrate of Magnesia, Sulph. of Potassium, Cream of Tartar and Rochelle Salts. What articles of diet are laxative in their effect ? Ans. Figs, Tamarinds, Cane Molasses, Cracked Wheat, Graham Bread. Oat Meal and all the small garden fruits. ANESTHETICS. What are Anaesthetics ? Ans. Medicines which destroy sensibility to touch and pain. What is the difference between the caustic and anaesthetic effect in this particular ? Ans. Caustics render the tissues insensible by devitalization; an anaesthetic acts upon the nerves to render them insensible to the impres- sion of an irritant. What is a local anaesthetic ? Ans. A medicine that renders a circum- scribed part insensible to pain. What is a general anaesthetic ? DENTAL MATERIA MEDICA. 33 Ans. A medicine that renders all parts of the body insensible ? Do local anaesthetics usually produce com- plete anaesthesia of a part? Ans. They do not. Mention the classes of medicines that fur- nish the local anaesthetics. Ans. Stimulants, narcotics and sedatives. Mention a valuable local anaesthetic Ans. Aconite, alcohol and chloroform, equal parts . Mention other local anaesthetics that are sometimes used. Ans. Cold produced by ether spray, elec- tricity, chloride of zinc, cocaine, tinct. of aconite root. What is the danger of the ether spray ? Ans, Freezing the gum and consequent slough . The objection to Chlo. Zinc. Ans, Produces great pain and endangers the life of the pulp if applied to sensitive dentine? Cocaine. — How obtained ? Ans. By distillation from the leaves of the cocoa plant. What are its medicinal properties ? Ans. Tonic and anaesthetic, It is also a powerful poison. 34 DENTAL MATERIA MEDICA. What preparations of the drug are most used in dental practice? Ans Oleate and citrate, 4 to 6 per cent, solutions. How is general ansesthesia produced? Ans. By an intoxicating drink, or by the in- halation of nitrous oxide gas, or the vapor of ether or chloroform. What previous incidental circumstance tends to modify the effect of an anaesthetic agent ? Ans. The previous state of mind — fearful apprehensions, want of confidence in the drug, want of confidence in the operator. What are the physical effects and pro- gressive stages noticeable in the patient? Ans. Stimulation, sedation, delirium, nar- cosis. Is complete anaesthesia usually necessary for a brief operation ? Ans. No. The sense of pain is of what two kinds ? Ans. Physical and mental. Which is the most difficult to be overcome ? Ans. The mental sense. How does this mental sense manifest itself? Ans. In apprehension and dread of suffering. In ordinary cases is anything more needed in using an anaesthetic than to overcome this dread and produce an indifference to pain? DENTAL MATERIA MEDICA . 35 Ans. There is not. Is this a common effect of alcohol and other anaesthetics ? Ans. It is. Nitrous Oxide. — What is it? Ans. It is a gas obtained from nitrate of ammonia; the nitrate is placed in a glass re- tort and melted, when it becomes water and gas. How is it used ? Ans. By inhalation. Can it be condensed into a liquid? Ans. It can be so condensed under very great pressure. Is it perfectly safe and harmless ? Ans. No. How is it, in this respect, compared with ether and chloroform ? Ans. It is the safest of the three. Ether Sulphuric. — Describe it. Ans. It is a colorless, volatile and inflam- mable liquid. What different qualities of ether are sold in the shops ? Ans. Commercial, pure, and stronger or concentrated. Which is used for inhalation ? Ans. The stronger. How is ether obtained? 36 DENTAL MATERIA MEDICA, Ans. By distillation of alcohol with sul- phuric acid. Chloroform. — What is it ? Ans. It is a colorless and volatile liquid, with a burning, aromatic and sweetish taste. How is it obtained ? Ans. It is obtained from alcohol by distilla- tion with chlorinated lime. How does it compare with the other anaes- thetics named? Ans. It is the most powerful, most persis- tent and the most dangerous. Upon what does the rapidity of its effects depend ? Ans. Upon the method of administering it and upon the susceptibility of the patient to its influence. CHAPTER ii. PHYSIOLOGY. [The Science, of Physiology, in its widest significance, ennbraces the entire Anatomy and Physiology of plants, animals and man. For convenience in study, each of these grand divisions is sub-divided into Anatomy and Physiology. Thus, we have Plant Physiology, Animal Physiology and Human Physiology. Anatomy and Physiology are separated on the life line. — Anatomy relating to the individual and dis- tinct parts of the body, regardless of life and function; Physiology to the organism, living, acting and in full performance of function. Hence, Anatomy can be best studied on the cadaver, while Physiology requires ex- perimentation on the living subject. Again, for purposes of special study and the more thorough application of the Science to the practical ser- vice of mankind, each sub-division is classified into sys- tems of organs related to each other in the performance of a distinct function. Dental Physiology is one of these latter classes or divisions, and pertains to the Dental Organs, embracing their origin and embryonic condition; their nutrition and developmental changes of form and structure; their arrangement in the jaws; their relations to contiguous parts, and their functions and special use as regards the entire physical econ- omy of the body. 38 DKNtAL PHYSIOLOGY. As a branch of study in a College, even this linnited amount of physiological lore is found to be too nnuch to be embraced in this course of Lectures. Hence, I have omitted the Nervous, Vascular and Lymphatic Systems in their relations to the Dental Organs, also Nutrition and Hygiene, trusting to the Lectures on General Physiology to supply this lack. It will be readily seen that their re- lations to the Dental Organs and associate parts are the same as their relations to other Organs and parts of the body, modified only by peculiarities of their anatom- ical structure.] DEFINITIONS. Define the words, structure, organic, in- organic, function, tissue. Ans. Structure; — Matter arranged in defi- nite form. Organic; — Possessed of such structural forms and forces as adapt an organized body to the spontaneous performance of function. Inorganic; — Such bocHes as have no such definite organization of parts, and perform no functions. Functions; — The activities or service which an organism is adapted to perform. Tissue; — A name apphed to all the different forms and parts of organized structure consider- ed separately. What does Physiology teach ? Ans. It teaches the development/structure, functions and laws t]iat govern organized bodies. DENTAL PHYSIOLOGY. 39 On what peculiar phenomena are the teach- ings of physiology based ? Ans. On the phenomena of life and function. What is the difference betwen Anatomy and Physiology ? Ans. The former pertains to organized bodies in a state of rest and inaction; the latter to the same bodies in a state of functional activity. What is that force called which produces functional activity ? Ans. Life-force. Give two definitions of life ? Ans. 1st, The term life, expresses the differ- ence between an organized body capable of motion from a source within itself, and the same organism incapable of motion from a sotirce within itself. 2nd, That force in organized bodies which resists the tendency to chemical decomposition. How do you prove the existence of such a force in organized bodies ? Ans. By its effects. What is the most common and appreciable exhibition of the life-force ? Ans. Motion, without the application of any external force. What is the theory of the objectors, concern- ing motion as a manifestation of the life-force ? 40 DENTAL PHYSIOLOGY. Ans. That motion is an inherent property of matter. What antagonistic theory is also held ? Ans. That inertia — a perpetual — rest, is an inherent property of matter. How may these opposing theories be recon- ciled ? Ans. Atoms of matter may be in motion relatively to each other, while, combined into molecules or larger bodies, the combined mass may be at perfect rest. What are the forces acting to produce motion in matter ? Ans. Chemical, electrical and vital. What is the minutest portion of vitalized matter called ? Ans. A cell, ameba, etc. Give a definition of a cell? Ans. The minutest portion of matter capable of the manifestation of life. What is the difference between the animal and the vegitable cell ? Ans, There is no known difference. Describe the cell as ordinarily found in or- ganized tissue. Ans. It consists of an outer filmy covering, called the cell wall, a semi-fluid, albuminous mass within, C2i.\\&(\. protoplasm, and a more solid mass floating in the semi-fluid called a nucleus. DENTAL PHYSIOLOGY. 41 What familiar example have we of this kind of structure ? Ans, An egg, deprived of its shell. Give its corresponding parts. Ans. The skin of the eg-or beneath the shell, represents the cell wall; the albuminous por- tion represents the protoplasm, and the yolk, the nucleus. Are these three parts considered essential to the existence of a cell ? Ans. Embryonic cells have no cell-wall and no nucleus. How is the cell-wall formed ? Ans. Of the waste matter thrown to the surface from within. What may be said of the independence of the cell ? Ans. Each individual cell is an independent organism. How does the cell derive its existence ? Ans. From the parent cell, — every cell from a pre-existing cell. How are cells propagated ? Ans. Usually by division, or by budding. What may be said of the functions of the cell ? Ans. All functional activity, nutrition and disease, are referred to the cell elements of the different organs. 42 DENTAL PHYSIOLOGY. THE DENTAL FOLLICLE. In what tissue of the body have the teeth their origin ? Ans. In the mucous membrane. Locate the mucous membrane. Ans. It is the hning membrane of the oral cavity and covers the internal organs and por- tions of the body; it is a continuation through the mouth, of the external skin. What general term is applied to this cover- ing of the body, both external and internal ? Ans. Derma. What other growths beside the teeth are peculiar to the derma ? Ans. Hair and nails. What is understood in dental science as the process of teething ? Ans. It includes all the processes of tooth formation from the development of the germs of the first set of teeth to the completion of the second denture in adult life. Of what three principal layers or parts does the mucous membrane consist ? Ans. The dermis, the epidermis, and the basement membrane lying between. Describe each. Ans. The dermis is the internal portion and is made up of connective tissue, blood- vessel, nerves and cells. DENTAL PHYSIOLOGY. 43 The epidei'mis is the external portion of the membrane and is composed of layers of cells of different forms. The basement membrane is a structureless film lying between the epidermis and the dermis. Name the different cells found in the epi- dermis ? Ans. Columnar or prismatic, spinous, hex- agonal or pavement, flattened, epithelial scales. In what part of the epidermis are the columnar cells found ? Ans. In the inner portion and resting on the basement membrane. Where are found the epithelial scales, and what are they ? Ans. Found on the external surface, and are considered to be the worn out and dead cells. Which are considered the embryonic cells ? Ans. The columnar layer. Have they a cell wall ? Ans. They have not. Have they a nucleus ? Ans. Not in their embryonic condition. What other contiguous structure undergoes the process of development simultaneously with the teeth ? Ans. The maxillary bone. 44 DENTAL PHYSIOLOGY. Does it come first into existence as a hard, mineralized tissue ? Ans. A cartilage is first formed, called MECKELS CARTILAGE. At what time and in what manner does it make its appearance in the human embryo ? Ans.* From the 15th to the 18th day of intra-uterine life; when the embryo appears but a gellatinous mass about one half inch in length, two faint and indistinct tongue-like processes may be seen which in a few days approach each other, swinging around into the form of a semi-circle. At about the 28th day, these semicircular processes become united. By the end of the first month the appear- ance is that of a glistening cartilaginous band. At the end of the second month the band has been condensed into a hard cord of about the size and appearance of a hog's bristle, at which time the embryo has attained the length of little more than three fourths of an inch and Meckel's cartilage about one fourth of an inch across its circular extremities. On what line do these first formed processes unite ? Ans. On the medium line. *The formation of Meckel's cartilage and the dental follicles as here presented, follows mainly the teaching ot Legros and Magi tot . DENTAL PHYSIOLOGY. 45 Where are the terminal extremities of Meck- els cartilage found ? Ans. In the malleus of the ear on either side. What purpose does this cartilage serve ? Ans. It serves as a temporary support for the soft tissues and cell elements of the tooth germs. When does it disappear? Ans. Usually vt'ith the development of the osseous structure of the jaw; sometimes, not until after birth. What is the first appearance and in what layer of cells is found the beginning of tooth formations ? Ans. In the line of columnar cells, which forms a deflection downward into the dermal tissue, carrying the basement membrane with it. At what period is this first development ? Ans. At the beginning of 2nd month. What is the epithelial ba7id and how is it pro- duced? Ans. It is the deflected portion of the epi- dermis, with the ridge above it, formed by the rapid prolification* of cells in the deflected por- tion and the crowding out of the older and worn out cells. *This term is derived from two latin words ; proles, oflfspring, and /acere, to make, to generate, to produce. The word ^'^prolif- eration''' very commonly used in the same sense, is derived from the words /ro/e5 and fere, to bear, in the sense of to carry; and only in its secondary sense does it signify to produce or generate. I consider, thereiore, prolificatiott the better word. 46 DENTAL PHYSIOLOGY. What cells are found in the deflected por- tion of the epidermis? Ans. The columnar cells in continuous line, and hexagonal cells in the intervening space. What is the next development of the pris- matic layer ? Ans. The formation of another fold from the inner or lingual side of the first fold, and projecting horizontally, — called a lamina. What is the third development ? Ans. A line of tubercles appear at intervals along the margin of the lamina, corresponding in number to the future teeth of the first set. What form do they assume ? Ans. They increase in length, turning downward, with a rounded extremity and neck, in bottle form. What is this pendent portion of the mem- brane called ? Ans. The enamel organ. Describe the first appearance in the develop- ment of the dentine organ ? Ans A papilla arises in the dermal tissue at a point immediately in contact with the rounded portion of the enamel organ, and simultaneously the bottom of the bottle-like form is rendered concave in exact correspon- dence to the form and size of the dentine papilla rising from the dermis. Cental physiology. 47 What change is next seen in the enamel organ? Ans. The change of the hexagonal cells into the stellate or star-shaped form. Their processes, inosculating, form a reticulum or net work. What change takes place in the columnar cells ? A.ns. The ends resting on the basement membrane are crowded into the hexagonal form, while their other extremities form into points and delicate processes, and unite with the processes of the stellate cells in the enclos- ure of the enamel organ. What is now the position of the basement membrane relative to these two forming organs ? Ans. It lies between and separates them. What are the cells employed in the formation of enamel called? Ans. Ameloblasts. What are the working cells of the dentine organ called ? Ans. Odontoblasts. What is the name of the cells employed in the formation of bone ? Ans. Osteoblasts. At what time does the dentine bulb begin to assume the tooth form ? 48 DENTAL PHYStOLOGY. Ans. At about the 9th week of embryo life. What tissue is next developed at the base of the dentine bulb ? Ans. The follicular wall, proceeding up- ward and surrounding the enamel and the den- tine organs. What third organ is formed to complete the group of the dental tissue ? Ans. The formative organ of the cementum. Where does it originate ? Ans. At the base of the dentine bulb, be- tween the follicular wall and the enclosed con- tents? Do any other organs have their origin here ? Ans. It is not probable that any other organs or functions are developed within the dental follicles, except those concerned in the formation of the dental tissues. Give the number and names of the dental tissues as indicated by the presence of their formative organs in the dental follicle. Ans. Five, viz: Enamel, dentine, dental pulp ^ cementum and peri- dental membrane. At what time are the follicles of the first set of teeth completed ? ' Ans. By the end of the 12th week. When the follicle is completed what change takes place ? DENTAL I'HYSIOI.OGY. 49 It is sundered from the epithelial band by absorption of its neck at about the lOth week. How early do the follicles of the permanent teeth begin their development? Ans. As early as the 15th or 16th week of embryo life. Which of the follicles of the permanent teeth is first, in point of development ? Ans. The follicle of the first molar. How soon is this succeeded by the follicles of the teeth anterior to it ? Ans. In about a week. Where do they originate ? Ans. Either from the necks of the primitive follicles, or from the epithelial lamina. At what time does the budding from the primitive cord take place ? Ans. Before the follicle is sundered from the epithelial lamina. Where originates the bud of the follicle of the first permanent molar ? Ans. From the epithelial lamina, back of all the follicles of the temporary set. What is the course of the follicles of the an- terior permanent teeth, relative to the positions of the primitive follicles ? Ans. They fall back of and below them . 50 DENTAL PHYSIOLOGY. What is peculiar in the form of the cord of the permanent teerh to distinguish it from that of the temporary ? Ans. It is longer and in spiral form. Which is first in the order of develop- ment, the follicle of the first permanent molar or the follicles of the permanent incisors? Ans. The first permanent molar — about a week previous to the incisor follicles. Where, according to Legros and Magitot, originates the follicle of the 12th year molar? Ans. From the neck of the follicle of the 1st molar. At what period of time does it begin to form ? Ans, At about the 4th month after birth. At what period of time does the follicle of the 3rd permanent molar begin its develop- ment ? Ans. At about the 3rd year after birth, bud- ding from the neck of the follicle of the second molar. How long a time is it in its follicular evolu- tion ? Ans. About 3 years. At what age of the child does this follicle lose its connection with the epithelial band? Ans. At about the 6th year of age. How long a time is this tooth in coming to such maturity as to emerge from the gum ? DENTAL PHYSIOLOGY. 51 Ans. Twelve or more years. Is this theory of Legros and Magitot, which derives the permanent teeth from the necks of the folHcles of the temporary teeth, accepted by all authors ? Ans. It is not; it is believed by some that all the teeth of the permanent set originate from the epithelial lamina the same as the temporary follicles. Development of the Maxillary, Bones and Mineralization of the Teeth. What is the relation of the bone structure to other parts and tissues of the body ? Ans. Bones give general form to the body, and are the frame work supporting the soft tissues through which the various bodily func- tions act. What may be said of the maxillary bones and of the teeth in this regard ? Ans. The maxillary bones help to give form to the face, and are subservient to the organs of mastication. The teeth are parts of the or- ganic structures employed in mastication. What direct and special purpose do the maxillary bones serve ? Ans. They support the teeth in a fixed position. What is the development of bone tissue called? Ans. Ossification. 52 DENTAL PHYSIOLOGY. Define ossification. Ans. It consists of a deposit of calcareous matter within the inter-spaces of cellular tissue. What class of cells accomplish this ? Ans. The osteoblasts. Does the process of ossification progress in all parts of a bone at the same time ? Ans. It begins at one, two or more points remote from each other, called centers of ossi- fication . How is continuity of the structure formed ? Ans. By a fusion of the radiating points from these centers of ossification. What is the economic reason for this method of development ? Ans. If the entire bone structure were in process of ossification at the same time, the nutritive system would be inadequate to supply the requisite amount of lime salts. From how many centers does the lower maxilla begin its ossification, and where lo- cated ? Ans. With two centers, located one in each lateral half of the jaw and on the line of Meckel's cartilage. How many centers of ossification are first noticed in the upper maxilla? Ans. Five centers. DENTAL PHYSIOLOGY. 53 What is the cause of cleft palate ? Ans. A failure in the union of the right and left halves of the palate processes of the upper maxilla, or of their union with the inter- maxillary bones. Where are located the inter-maxillary bones ? Ans. They form the anterior portion of the palate process. Where is the line of union with the palate process ? Ans. Between the cuspids and lateral in- cisor teeth. What teeth are developed in the inter maxil- lary bones ? Ans. The incisors. Explain the formation of double cleft palate and hare-lip. Ans. The inter-maxillary bones may fail to unite with the palate process on one side or the other, or on both sides; or the inter-maxil- lary bones may be entirely wanting, and a double cleft be the result. How is the groove formed in which the den- tal follicles are formed ? Ans. By the ossification of the external and internal plates of the jaw and their union at the basilar portion. At what time and in what manner are the alveoli formed ? 54 DENTAL PHYSIOLOGY. Ans. At about the fourth month of foetal Hfe cartilaginous processes project from the opposite sides of the maxillary groove, which unite and become ossified, thus forming the transverse septa of bone that separate the alveoli from each other. What is the difference in the degree of ad- vancement of the different follicles ? Ans. At this period there is no perceptible difference. MINERALIZATION. In what part of the tooth structure does mineralization begin first ? Ans. In the dentine bulb, and in that part of the bulb that forms the cutting edges of the incisors and the cusps of the other teeth. What is the arrangement of the odontoblast cells for the process of dentinification ? Ans. The larger cells are arranged along the periphera of the pulp and are called the odontoblast layer. Explain how it is that the tubular structure of dentine is formed? Ans. The odontoblast cells throw out pro- cesses from the external extremities, and around the processes the lime salts are deposited, the process lengthening with the thickening of the cap of dentine. Thus, if at any time the pulp t)ENTAI. PHYSIor.Or.V. 00 and these processes be withdrawn from the forming- dentine, the dentine cap would present perforations equal in number to the processes, and running entirely through it to the line of contact with the enamel organ. What are the processes occupying the tubules of the dentine called? Ans. Dentinal fibrilli. As age advances, what change takes place in the fibrilli and the tubules ? Ans. Both the tubules and the fibrilli de- crease in size, becoming very small in middle life, and in old age, the extremities are found wholly obliterated. What then is the tendency of the pulp from childhood to old age ? Ans. It tends to obliteration. Does it become wholly obliterated by a physiological process ? Ans. It does not usually, but becomes dor- mant after the maturity of the tooth structure. May it become stimulated into activity again, and how ? Ans. It may be stimulated to take on for- mative action by abrasion of the tooth crown or by disease. When a thin cap of dentine has been formed, what change takes place in the enamel organ ? b6 IJENTAl PHYSiOLO(i'y^. Ans. The peripheral cells lying in imme- diate contact with the cap of dentine become elongated to two or three times their original length and send out from their inner extrem- ities long processes to inosculate with like processes of the stellate cells in the central portion of the organ. As they are compacted together, what form do they take ? Ans. The hexagonal form, at their bases, while the extremities toward the interior of the enamel organ are pointed. Have these cells any cell wall ? Ans. They have not. Explain the process of formation of enam- el rods or prisms. Ans. The lime salts are first deposited at the base in contact with the cap of dentine, each enamel rod taking^ the exact form of the cell, which by compact becomes hexagonal, and the lime salts from each cell (there being no cell wall) are deposited in immediate contact with the lime salts deposited from each con- tiguous cell . In what form is the lime thus deposited? Ans. In solution, to harden by crystaliza- tion. What becomes of the cell as the lime deposit increases ? DENTAL PHYSIOLOGY. 57 Ans. It becomes less and less in substance, till what remains is atrophied in the central portion of the enamel rod. In a fracture of the enamel where is the line of cleavage, and why ? Ans. Along the central portion of the rods; because this portion being formed by the cell while wasting its strength and substance is weaker and in this portion of the enamel rods is found the larger portion of what remains of the animal or organic tissue. What is understood by the internal epithelium and what by the external epithelium ? Ans. The line of columnar cells in imme- diate contact with the formed dentine is called the internal epithelium and the remaining peripheral cells of the enamel organ are called the external epithelium. What becomes of the external epithelium ? Ans. The cells atrophy and remain upon the surface of the formed enamel, as a kind of "cuticle of the enamel" presumed to be "Nasmyth's membrane." What other organs are developed or modified contemporaneously with the teeth ? Ans. The stomach and the intestinal canal. What change takes place in the stomach ? Ans. It is changed from a mere tube as found in the infant, to the the pouch-Hke form. 58 DENTAL PHYSIOLOGY. How is this change brought about ? Ans. By a development of the lower curva- ture of the stomach to two or three times the length of the upper curvature. Why is this change necessary ? Ans. The development of teeth is an in- dication of a need of solid food, and the en- largement of the stomach to the pouch-like form is for the purpose of detaining such food for the process of digestion. EMERGENCE OF THE TEETH.* Deciduous Teeth. In what stage of development are the teeth when prepared to emerge ? Ans. The crowns are formed. Which teeth of the first set are earliest in cutting the gum ? Ans. The lower central incisors. At what age of the infant do these teeth begin to emerge ? Ans. At from 5 to 8 months of age. Which are the last teeth to emerge and at what apfe ? Ans. The cuspids; from 30 to 32 months of age. *The word "eruption" commonly used in this connection is a disgusting word, applied to loathsome forms of disease, and has no place in Physiology. One might as well speak of an e.ruftion of corn, or of a hill of potatoes erupting, as to speak of the eruption of the teeth. DENTAL PHYSIOLOGY. 59 At what age does the infant get its mastica- ting teeth ? Ans. At the age of 24 to 30 months. What does the development of the teeth in- dicate as to the diet of the child ? Ans. That solid food should not be given to a child until its masticating teeth have fully emerged. What may result from taking solid food before the masticating teeth have emerged ? Ans. Cramps, spasms, fits and other signs of indigestion. To what cause are such symptoms often attributed ? Ans. To the process of "teething." Is ''teething'' a physiological or a pathological process ? Ans. It is a physiological process. Is it proper in tables of mortality to attribute the death of infants to "teethingr ?" Ans. Death should not be attributed to a physiological cause. To what should such deaths be ascribed ? Ans. To some attending pathological con- dition. What is the force which causes the teeth to emerge ? Ans. Vital force. 60 DENTAL PHYSIOLOGY. How does it operate ? Ans. By growth; developing first the neck, then the remaining portion of the root. What resistance is offered to the emergence of the teeth ? Ans. 1st. The folHcular wall; 2d. The bone forming a cap over the alveoli; 3d. The dense fibrous tissue forming the gum; 4th. The mucous membrane. By what process is this resistance overcome ? Ans. By absorption of the overlying tissues. Suppose the absorption does not progress as rapidly as the growth of the advancing tooth, what will be the result ? Ans. Pain more or less intense, sometimes causing spasms. What is the chief cause of the pain? Ans. The resistance offered causes a re-ac- tionary force downward upon the pulp. How is this pain relieved ? Ans, By friction and pressure upon the gums to induce more rapid absorption, and in cases of intense pain or general disturbance of the system, by lancing the gum. What is the theory concerning the exciting cause of absorption ? Ans. That the pressure of the advancing tooth induces absorption of the overlying tissues. t)ENTAL] PHYSIOLOGY. 61 What would be the result if mere mechanical pressure induced absorption ? Ans. The pressure of the different organs of the body upon each other would induce their absorption — thus the body would become self- destructive. What should be the statement of the pres- sure theory of absorption ? Ans. The pressure of a foreign body induces absorption. After the emargination of the alveoli to allow the crowns to pass through, what change takes place regarding the alveolar bone ? Ans. Absorption ceases and there is a re- newal of bone-formation at the margins of the alveoli, to embrace the neck of the forming tooth. When the crowns have fully appeared how far advanced in mineralization are the roots ? Ans. They have attained about half their length . PERMANENT TEETH. In a harmonious development of the teeth and jaws, what are the indications of the time approaching for the development of the per- manent teeth ? Ans. The expanding of the alveolar ridge, an4 the spreading apart of the deciduous teeth. 62 DENTAL PHYSIOLOGY. If the teeth do not spread what does this in- dicate as to the future development? Ans. A contracted jaw, crowding and dis- placement of the permanent teeth. Which is the first of the permanent teeth to appear ? Where ? At what age ? Ans. The first inferior molars; — back of all the temporary teeth; — at about the sixth year of age. Which teeth emerge next, and at what age ? Ans. The lower central incisors, at about seven years of age. What class of teeth take the places of the deciduous molars ? Ans. The bi-cuspids. At what age do they appear ? Ans. At from nine to ten years of age. What position do they occupy in the jaw be- fore their emergence ? Ans. The crowns of the bi-cuspids are lo- cated between the roots of the deciduous molars. By what process are the temporary teeth re- moved to give place to the permanent teeth ? Ans. By absorption of their roots. Suppose that, on the pressure theory of ab- sorption, the advancing crown of the perma- nent tooth impinges upon the root of the tem- porary tooth, what is the result ? DENTAL PHYSIOLOGY. 63 Ans. The absorption of the root ceases at the point of pressure. How is the process of absorption of the roots of teeth accompHshed ? Ans. The absorbing organ exudes a sol- vent. What is the supposed origin of the absorb- ent organ ? Ans. Some suppose it to be a modification of the cementoblasts of the root membrane. Others that the tooth pulp having ceased its work of tooth formation, becomes an organ of absorption to take down the work of its own formation. What evidence is there that the pulp exer- cises a controlling influence in the work of re- moval of the roots of the temporary teeth ? Ans. The fact that when the pulp dies the work of absorption ceases as a physiological process, and afterward progresses only patho- logically. What are John Tome's theory and observa- tions concerning the absorbent cells? Ans. That the work of absorption of the roots of teeth is accomplished by a class of cells called "giant cells," which he describes as clusters of cells. 64 DENTAL PHYSIOLOGY. Functions and uses of Dentine, Enamel, Cementum, Alveolo-Dental Mem- brane, AND OF the Teeth and Jaws. DENTINE. Which of the tooth tissues gives form to the tooth ? Ans. The dentine. Remove all the other tooth tissues and the dentine remaining shows the typical form of the tooth. What are its chief characteristics which adapt it to constitute the main body of the tooth structure ? Ans. Its density, its elasticity and its vitality. Define elasticity. Ans. That property of any substance which causes it to recover its form when stretched, bent, or indented. What is the advantage of this property in the dentine of teeth ? Ans. It prevents breaking the structure under the force of mastication. Why does not dentine meet all the require- ments of a hard tissue in tooth formation ? Ans. It is not sufficiently dense to resist abrasion. DENTAL PHYSIOLOGY. 65 ENAMEL. What of enamel as to its density ? Ans. It is the most dense and the hardest of all organized substances. What uses does the enamel serve ? Ans. Primarily, its use is to protect the den- tine from abrasion. Secondarily, to protect it from decay, and thirdly, to beautify the teeth. What evidence is there that protection from decay is not the primary use of enamel ? Ans. 1st. In nearly every mouth teeth do decay. 2d. Enamel and dentine are composed chief- ly of the same element, — lime. 3d. Teeth with the enamel worn off from use. remain for years without decay. 4th. Teeth ground or filed in a dental opera- tion so as to expose the dentine, do not, for that reason, necessarily decay. What are the conditions of exposed dentine which serve to protect it against decay ? Ans. Smoothness and cleanliness of the surface. DENTAL PULP. What is the chief function of the dental pulp? Ans. It is the formative organ of the den- tine, 66 DENTAL PHYSIOLOGY. Has it any other function ? Ans. It is an organ of nutrition as regards its own substance, and, for a limited time after birth, it nourishes the dentine. Is there any evidence that the nutritive func- tion pertains to the hard substance of the tooth after the maturity of the tooth structure ? Ans. There is not. What are some of the facts and arguments in support of this theory. Ans. 1st. Teeth are different from every other structure, so that the laws governing other structures are not applicable to them. 2d. The hard tooth tissues are not wasted by physiological processes like other tissues of the body, hence do not need the same renewal. 3d. In their nature they are more permanent than any other organic structure. They resist decay on exposure to external influences, for hundreds of years after all other tissues of the body are dissolved. ^ 4th. Hones may be destroyed by disease or by a surgical operation, and nutrition will re- store the lost part under favorable circum- stances; but no lost part of a tooth is ever re- stored by nutrition under any circumstances. What may be said of the pulp as a necessity in mature teeth ? DENTAL PHYSIOLOGY. 67 After a requisite number of years in matur- ing the tooth structure the pulp is not essential to the integrity of the other tooth tissues. In what condition is the pulp after completing its work as a formative organ ? Ans. In a dormant condition. Under what circumstances is it again excited into action? Ans. By abrasion, or by decay causing irritation. Is this secondary formation, known as sec- ondary dentine, identical with the first forma- tion ? Ans. It is not. It is less dense and less regular in its structure. Name analogous cases of other organs com- pleting their organic work and becoming dormant. Ans. The root membrane ceases its forma- tive work of depositing cementum, and exists only as an organ of nutrition. The genital organs become dormant late in life and do not renew their vigor. CEMENTUM. What is the special use of cementum? Ans. Being intermediate in the density of its structure it serves to form a union of the soft tissue of the root-membrane with the den- 68 DENTAL PHYSIOLOGY, tine, thus preserving the vitality of the tooth after the death of the pulp. What two functions has the alveolo-dental membrane ? Ans. It is the formative organ of the cementum, and also the formative organ of the parietes of the alveoli. What does this double function indicate as to its structure ? Ans. That it exists as a double membrane. What conflicting teaching of authorities points to the same conclusion ? Ans. That the root membrane is a continu- ation of the periosteum of the alveolar ridge; and again, that it originates in the dental follicle. It cannot originate from these two different sources except it be a double mem- brane. Are the two layers or parts of this membrane sepefable, and by what means ? Ans. They are separated in the extraction of teeth. A membrane is found on the ex- tracted root, and also a membrane found lining the socket. What would be the result if the alveolar wall was denuded of its periosteum when a tooth is extracted ? Ans. Necrosis of the bone which consti- tutes the socket. mJ(^i/iMJ^ DENTAL PHYSIOLOGY. 69 What evidence is found in the structure of the two parts or membranes ? Ans. They are not of the same structure. Is there any evidence to prove, that the fibres composing the membrane next the cementum connect and become continuous with the net work in the part next to the bone ? Ans. As it is claimed to be only an"insensible" union, there is no proof of continuity of tissue. What evidence of duality of the membrane is found in the nerve and vascular supplies ? Ans. The nerve and vascular supplies are from two sources; from the nerves and vessels that supply the periosteum of the alveolar ridge and the gum, on the one hand, and from the nerves and vessels that supply the pulp, on the other hand. What evidence is found in the pathological conditions of the membrane ? Ans. In diseased conditions arising from peri- dental irritation it deposits cementum on the root, but no osseous formation on the wall of the socket opposite; showing that the nutrition of the two membranes is not from the samesource. For, if the blood vessels and nerves passed through from side to side, there would be the same inflammatory action on both sides and the same deposite on both sides, creating dental anchylosis — a condition never known to exist. 70 DENTAL piiVsioioGY. What united functions do the teeth and jaws serve ? Ans, The function of prehension and of mastication. Define prehension, Ans. The act of seizing a portion of food presented for ahmentation. What is mastication ? Ans. Crushing, grinding, pulverizing and insalivating food. What are the movements of jaws employed in mastication ? Ans. Movement is confined to the lower maxilla, working against the upper as a fixed body. There are three varieties of movements down and up, right and left, forward and backward; there is also a combined move- ment. What class of muscles furnish the power in mastication ? Ans. The temporal and buccal muscles. What other muscles aid in mastication ? Ans. The oral and lingual muscles are necessary aids. The oi^bicularis oris closes the mouth and prevents the food from escaping, and the lingual muscles aid the buccal in keep- ing the food between the jaws, during the pro- cess of mastication. What is the purpose of insalivation ? bENTAL PHYSIOLOGY. ^1 Ans. Insalivation serves three important purposes. 1st. It softens hard food so that it can be more readily masticated. 2nd. It compacts hard and dry food into a bolus suited to deg-lutition . 3rd. It is an aid to digestion in the stomach. *^ n <=> (^ / v XT \ CHAPTER III. PATHOLOGY AND THERAPEUTICS. [The study of Pathology has in modern times come to be, in Dentistry as in Medicine, the key to a successful practice. By far the largest number of teeth presented for a dental operation are not only in a pathological con- dition, but in such a pathological condition as to demand a careful investigation of disease and to require a change of conditions by therapeutical treatment, as necessary means of saving them. Much more attention has been given by the profession to Therapeutics than to Pathology. But to study thera- peutics independently of pathology is of no more use than to study the literature of a medical almanac. To treat disease by name and not by nature, is quackery. To use medicines by name and not according to their nature is also quackery. To treat disease, however simple its form, rationally and successfully, requires a knowledge of the working of disease underneath the surface and hidden from view. Disease must be treated according to its hidden nature. Pathology treats of both the visible and hidden workings of disease. Not to know pathology is to sacrifice to the forcep hundreds of teeth annually, that might have been saved had their diseased condition been understood and ration- ally treated. We speak of diseased action, implying the op- eration of a force within the tissues; not necessarily anew force, but the normal physiological force perverted ; a force tending by perverted functions to tear down what it had before built up and supported. This change of activities within the tissues is usually a fact of self-consciousness, The individual feels it sensibly, and expresses it in words with a meaning experimentally familiar to all mankind, — such as soreness, pain, inflammation, swelling and a long list of other words, equally significant, but among them none more significant or more comprehensive than the word inflammation. DENTAL PATHOLOGY AND THERAPEUTICS. 74 Writers of reputation and authority in pathology have said that the history of any disease is but the History of the Inflammatory processes manifest in its initiation and progress. A work on general pathological surgery could not be intelligently written without a thorough exposition of In- flammation. The same exposition is needed in dental surgery ; for the same processes of diseased action are manifested in the teeth and associate parts. Inflammation is one and the same thing every where, modified only by peculiarities of structure and intensity of action. I need therefore offer no apology for giving so large a place to the study of the inflammatory pro- cesses, without which dental pathology cannot be under- stood and pain cannot be interpreted. A study of the diagram, heading this chapter will make plain the teach- ing of the text. It is a device of my own to show by a glance of the eye out of what conditions and inflammatory processes any given development of disease has grown. Thus tumefaction, necrosis, molecular death or any other new formation or changed condition may be traced back to its source, and all the processes contributing to its formation may be seen at once.] Of what does pathology treat ? Ans. Of the origin and progress of those changes in the structure or functions of the body, which constitue disease. How does dental pathology differ from general pathology ? Ans. It differs only in those modifications of disease which result from peculiarities of structure and susceptibilities of the tissue involved. What is the literal signification of the word pathology. DENTAL PATHOLOGY AND THERAPEUTICS. 75 Ans. The science of sufferincr, or the science which treats of the body in a condition of pain. Is pain a necessary attendant of disease ? Ans. It is not. What is the Hteral signification of the word disease ? Ans. Want of ease, discomfort. Define dis^diS^ pathologically considered. Ans. Any abnormal condition or any func- tional change of those processes which consti- tute perfect health. Can the beginning of disease always be recognized ? Ans. It cannot, because it may be confined to an area so small as to involve but a single cell, and that in an obscure portion of the body. What word expresses the chief manifesta- tions of diseased action ? Ans. Inflammation, Give a comprehensive definition of inflamma- tion. Ans. It is the aggregate of those results which manifest themselves in an injured part, (Burdon Sanderson.) Give Strieker's definition. Ans. ''Inflammation manifests itself in two features, (1,) An active hypersemia, and (2,) an active tissue metamorphosis." 76 DENTAL PATHOLOGY AND THERAPEUTICS. What is the meaning of the word hypersemia ? Ans. An excessive flow of blood to a part. What other words are used as synonymous terms? Ans. Fluxion, determination, inflammation. What is understood by metamorphosis of tissue ? Ans. A change of tissue into another and different kind of tissue. Upon what does the extent and activity of the inflammatory processes depend ? Ans. Upon the susceptibility of the part to impression by foreign influences. What are the most commonly observed features of inflammation ? Ans. Heat, redness, pain, swelling and im- paired function. Are all these manifestations present in every case? Ans. The manifestations vary with the character of the tissue involved, and the severity of the injury. Is inflammation a simple condition ? Ans. It is a series of changing conditions, each the result of the preceding condition. What is the firsfr in the series of inflamma- tory conditions ? Ans. Irritation. bENtAL PATHOLOGV AND THERAPEUTICS. 77 What is understood by an irritant? Ans. The slightest foreign touch, element or influence, affecting the body to disturb the harmony and perfect performance of any of its functions. What is the distinction between excila?its and irritants ? Ans. Excitants are noi'inal stimuli to the functions. Irritants are abnormal stimuli, caus- ing abnormal functional action. Under what circumstances may a normal ex- citant become an irritant ? Ans. Any stimulus, normal in kind, but ab- normal in quantity, may become an irritant, (e. g.) Light, too intense or too feeble, irritates the eye. Food, either in too large or too small a quantity, irritates the stomach. In what part of the anatomy is the progress of inflammation most readily traced ? Ans. In the vascular system. What are the first observable effects of an ir- ritant upon an exposed surface ? Ans. Increased redness and warmth. Give the pathology of irritation ? Ans. Irritation excites the cell elements of the capillary vessels into active contractions and elongations, which has the effect to quicken the circulation of the blood and induce warmth. Warmth also expands and gives increased 78 DENTAL PATHOLOGY AND TIIERAPEUTICS4 length to the capillaries, so as to expose to view a greater amount of blood than is normal, thus causing an increased redness called deter- Tnination of blood or hyperaemia . The expan- sion of the blood vessels causes slight pressure on the filaments of nerves supplying the tissue, thus causing discomfort and the attention of the mind to the affected part. What is the result of this vascular activity ? Ans. If continued, a permanent dilatation of the vessels is the result. How does this affect the flow of blood ? Ans. It retards it. What change is indicated by the permanent dilatation of the vessels and the retardation of the blood flow . Ans. A change from the first to the second stage of the inflammatory processes. Why is the term inflmnmation applied specially to the second stage ? Ans. Because of the number of varying in- flammatory conditions resulting directly from either its acute or chronic form. Inflammation, Acute, — Give the symptoms of the second stage of the inflammatory processes. Ans. It is characterized by warmth, a sense of fullness, pressure, slight swelling and pain steadily increasing, or increasing at intervals. bfeNTAL PATHOLOGY AND THERAPEUTICS. '/'9 What is the pathology of inflammation ? Ans. The rapidity of the vascular action in the first stage induces warmth; the warmth ex- pands the blood vessels; the expansion increases the volume of blood and eives the sense of fullness, pressure and the swollen condition; and the over-full blood vessels, pressing upon the filaments of nerve supplying the inflammed tissue, cause the pain, which increases with the expansion of the vessels. Explain the therapeutical effect of heat and cold in case of acute inflammation of the dental pulp. Ans. Cold increases the pain by contract- ing the vessels and suddenly checking the ac- tivity of the circulation, this creates a re-action- ary pressure upon the nerves in the surround- ing tissue and consequent pain. Heat expands the vessels and promotes a more free circula- tion, and thus relieves the pressure and the pain. Give a diagnosis distinguishing the pain of irritation in the first stage, from the pain of acute inflammation in the second stage. Ans. In a case of pulp irritation the pain will cease and all other symptoms speedily sub- side on removal of the irritant. In case of acute inflammation a removal of the irritating 80 DENTAL PATHOLOGY AND THER APEljTICS. cause may lessen the pain, but will not restore the pulp to its normal condition. What is understood by acute and what by chronic inflammation ? Ans. When inflammation takes a decisive, active and painful form, running rapidly through the several processes, it is called acute. When from a slight injury or from a lessening of the activity of the acute manifestation, the in- flammation is prolonged with lessening pain and discomfort, it is called chronic. Does acute inflammation, unchecked, neces- sarily become chronic ? Ans. It may result in congestion or in chronic inflammation. Inflammation, Chronic. — What is the most noticeable characteristic of chronic disease, dis- tinguishing it from the acute form ? Ans. Its comparative painlessness. Are prolonged continuance and diminution of pain the most important characteristics of chronic inflammation ? Ans. They are not. The most noticeable characteristic of chronic inflammation is noticed in the changed functions of the part — changes effected by time. Upon what law of the physical organism are such changes based? DENTAL PATHOLOGY AND THERAPEUTICS. 81 Ans. Upon the law o{ functional habitude. All the functions of the body are subject to train- ing and adaptation to surrounding conditions. Hence, the continued irritation trains the func- tions of the tissues involved, to an adaptation to their changed conditions and to a less degree of susceptibility to the impression of an irritant. Thus, pain is lessened. Give examples. Ans. A tooth pulp exposed and suffering acute inflammation, will not tolerate contact with the atmosphere or with any solid substance; but when the inflammation becomes chronic the functions of the pulp become changed and ad- justed to the abnormal environment and it will tolerate the presence of the air, saliva and food without the sense of pain. The functional habitude of the stomach and the nervous sys- tem becomes changed by the continued use of tobacco, however irritating it may at first be. How is the chronic condition of the dental pulp affected by pressure of a foreign sub- stance ? Ans. Slight pressure causes no pain only the sense of touch. Severe pressure, as that of mastication, becomes an irritant* or an injury and causes a return of acute inflammation. Is the pulp in its normal condition peculiarly sensitive to external influences ? 82 DENTAL PATHOLOGY AND THERAPEUTICS. Ans. It is not It may be touched by the finger or with an instrument without causing pain. How does it become changed to the painful condition ? Ans. By inflammation. What changes of tissue are liable to result from chronic inflammation ? Ans, Chronic inflammation of the oral tissues is liable to result in hypertrophy or in one of two forms of metamorphosed tissue, viz; Induration or tumefaction; or the chronic condition may again, by irritation, become acute and pass speedily into congestion. Hypertrophy, Define. — Ans. Hypertrophy is an excessive growth of normal tissue by normal functions in a state of chronic in- flammation. What is the pathological difference between hypertrophy and the inflammatory swelling of the second stage ? Ans. The swelling in the second stage of the inflammatory processes is caused by the expansion and over fullness of the blood vessels. The enlargement of hypertrophy is caused by a multiplication of the cell elements of the tissue. What tissues of the mouth are most liable to hypertrophy ? Ans. The gum and mucous membrane. DENTAL PATHOLOGY AND THERAPEUTICS. 88 Give the pathology of hypertrophy ? Ans. The irritation of the first stage induces ahypersemic condition of the gum and a great- er flow of blood than is needed in the support of normal tissue; the excess is utilized in the development of an abnormal amount of tissue of the same kind. Name the two kinds of hypertrophy. Ans. Physiological and pathological. What is physiological hypertrophy ? Ans. It is an excessive nourishment and development of normal tissue by continued excitation and use, — e. g., the development of the muscle of a blacksmith's arm. What is pathological hypertrophy as distin- guished from the former ? Ans. It is an excessive growth of normal tis- sue by continued irritation, — i. e. norrmd excita- tipn so excessive as to become irritation. In what manner does hypertrophy of the gum manifest itself? Ans. In the growth of long points of gum in the inter-spaces of the anterior teeth, or a thickening of the margin of the gum along the buccal faces of the bi-cuspids and molars. What is the proper treatment of hyper- trophy ? 84 DENTAL PATHOLOGY AND THERAPEUTICS. Ans. Excision. Take pointed scissors and remove the long points of gum growing in the inter-spaces of the teeth, down to the level of the gum on the labial faces of the teeth, extend the cutting with scissors or bistoury along the buccal sides of the bicuspids and molars, if needed. Then reduce the inflammation with stimulants and astringents; wood creasote and tannin are suggested as among the best. They do not combine but they act harmo- niously when used together on the same pledget of cotton. INDURATION. How does induration manifest itself ? Ans. In a circumscribed, hardened swelling. When it pertains to the gum it presents to the touch a feeling much like bone underlying the gum. A hardened condition may manifest itself also in the buccal muscles or in the muscles of the neck, resulting from a diseased tooth. What is the pathology of induration ? Ans. It is a condition of chronic inflammation in which all the functions of the diseased part are morbid and inactive; the circulation is greatly impeded; exuded lymph coagulates in the interstices of the cells; the excessive amount of blood is utilized in producing a kind of cell plethora; the individual cells be* DteNTAL PATHOLOGY AND THERAPEUTICS. 85 come enlarged and fibrillated; all the above conditions contribute to produce the hardness of the tissue. What is the difference between hypertrophy and induration ? Ans. Both are enlargements of tissue, but in hypertrophy the enlargement is by the mul- tiplication of cells, while in induration it is the enlargement of individual cells, and not an en- largement by cell-prolification; in hypertrophy the circulation is active; in induration it is retarded; in hypertrophy the enlarged part has a normal softness, and in induration the enlarg- ment has an abnormal hardness. What is the external treatment for an in- durated condition of the neck and cheek ? Ans. Hot fomentations and persistent and active stimuli. Capsicum is very effective. What is the treatment for indurated gum ? Ans. Application of extract of capsicum, severe lancing to promote suppuration, or the use of a seaton for the same purpose — the latter when other methods fail. TUMEFACTION— Describe. Ans. Tumefaction is a condition of chronic inflammation, by which is produced an exces- sive growth of abnormal tissue by the develop- ment and exercise of abnormal functions. It is 86 DENTAL PATHOLOGY AND T^HfeRAPEUtlCg. characterized in its development and growth by its independence of the rest of the body. In what respects does tumefaction differ from hypertrophy ? Ans. Hypertrophy consists of the forma- tion of an abnormal amount of tissue of the same kind as the surrounding tissue. Tume- faction, the formation of an abnormal amount of tissue of a different kind from the surround- ing tissue. Hypertrophy shows no line of de- markation between the normal and abnormal tissue. Tumefaction exhibits a difference in color and in texture, and rises above the level of the surrounding tissue. What different kinds of tumors are common- ly found in the mouth and where located ? Ans, Epulis tumors, originating in the periosteum of the alveolar ridge. Cystic tumors originating, in the mucous membrane. Vascular tumors, springing from some blood- vessel supplying the gum. Describe the appearance of each. Epulis. — This tumefaction is usually found in the interspaces of the anterior and bi-cuspid teeth; has a deeper red color than the sur- rounding tissue, with a roughened, seeded or cauliflower appearance; about ragged edged roots of teeth, it is found in nodular clusters; its structure is fibrous. DENTAL PATHOLOGY AND THERAPEUTICS. 87 Cysts of the mucous membrane are of lighter color than normal mucous tissue and glistering; They are usually filled with mucous of degen- erate character. Their structure is mem- branous. Vascular Tumors are of a deep red color, highly vascular, venous blood predominating; they are smooth and shining, and more or less fibrous. Treatment. — Epulis should be treated by ex- cision. — the bistuory entering the healthy tissue about a line from the base of the tumor, should be passed entirely around and under it, as deep in as the periosteum, so as to remove it entire. After the removal the wound should be treated with caustic carbolic acid, thoroughly, in order to destroy the vitality of any remain- ing fibers. Vascular Tumors should be removed in the same manner. A CYSTIC tumor should be emptied of its mucous contents by a careful puncture at the lowest pomt and then should be collapsed by pressure. This can usually be done by a pad of considerable size dipped in dry tannin and held firmly upon the cyst by pressure of the lips or cheek. Medicinal treatment should be confined to the external surface of the cyst and consist of the use of stimulants and astrincrents. 88 DENTAL t'ATHOLOGY AND THERAPEUTICS. When any organ or tissue is in a state of acute inflammation, what other condition than the chronic state is Hable to supervene? Ans. CONGESTION. What are the symptoms of congestion ? Ans. Beginning with the warmth and hy- peraemia of acute inflammation, the heat pres- sure and pain, greatly increase. When the stage of congestion is fully reached, a severe throbbing pain is experienced; this, therefore, becomes a sure, diagnostic sign of congestion. What is the pathology of congestion ? Ans. The retardation of blood-flow which begins in the second stage is continued in congestion, the current becoming slower and slower, which causes a massing together of the corpuscular elements of the blood and an en- gorgement of some of the capillary vessels, while others permit but a limited flow of blood through the inflamed part. This increases the pressure and the severity of the pain. With the increasing number of the capillaries that become engorged, comes the arrest of the blood-flow to such an extent as to cause almost complete stasis. Blood stasis, therefore, is the most prominent histological feature of conges- tion, although it does not pertain to all vessels. How does the severity of the pain of con- gestion become intermittent? /^^H-./UL*''^^ / DENTAL PATHOLOGY AND THERAPEUTICS. 89 Ans. In one of two ways; 1st, By the gorges in the capillaries being broken through by the force of the blood current; or, 2nd, by the establishment of circumferential currents; the rebound of the blood which fails to pass the gorge causes a back-set of the current to the anastomoses of other vessels which the blood enters and thus passing around the inflamed area, temporarily relieves the pressure and the pain . What is the cause of the throbbing pain of congestion ? Ans. A throb is experienced with each pul- sation of the heart in consequence of the sudden arrest of the current of the blood by the engorgement of the capillary vessels in the inflamed part. • The throb is the rebound of the blood current. Why is the throbbing pain of a congested tooth pulp more severe than in other soft tissues ? Ans. Because the tooth pulp is confined by walls of dentine which will not admit of any expansion -of the blood vessels. What is the natural and necessary result of inflammatory stasis ? Ans. A loss of nutrition in the part where it occurs, a consequent impairment of the 90 DENTAL PATHOLOGY AND THERAPEUTICS. vascular functions and a weakening of the walls of the vessels themselves. If resolution does not take place at this junc- ture what must be the inevitable result ? Ans. The weakening of the vascular walls must continue until they become permeable; transudation of the contents of the vessels takes place and an infiltration of the same into the surrounding tissues. What peculiarity in the structure of capillary vessels favors their easy permeability ? Ans. Their coatings being composed of cells merely glued together by their protoplasm, when their functions become impaired by the processes of inflammation, the cells are easily parted from each other. What familiar illustration may be noticed ? Ans. The bleeding of inflamed gums, the Capillary vessels parting on the slightest touch of an instrument. What of the surgical operation of cupping ? Ans. Its accomplishment depends upon the easy parting of the cell elements of the capillaries. What is inflammatory transudation and in- filtration of blood into the surrounding tissues called ? Ans. Suppuration or pus-formation. DENTAL PATHOLOGY AND THERAPEUTICS. 91 Give the pathology of pus-formation. Ans. The permanent dilatation of the vessels and the retardation of the current of the blood, in the second stage, produce an en- gorgement of the capillary vessels, a massing together of the blood corpuscles and a weaken- ing of the walls of the vessels to such a degree as to permit a transudation of liquor sanguinis. - Immediately following, the white blood corpuscles which float languidly along the walls of the vessels, are excited into un- usual activity, send out points or processes, which penetrate the walls of the vessels and pass through, followed by red corpuscles in smaller numbers and by dead corpuscles in blood clot and other debris of broken down tissue. What are these cells, passing out of the blood vessels into the surrounding tissue, called ? Ans. Emigrant cells. Are the emigrants the only pus cells ? Ans. They are not. The connective tissue cells bordering the inflamed part are excited to a rapid prolification of embryonic cells for the purposes of repair and restoration of the broken down tissue; some of these cells minele freely with the emigrant cells, and both kinds are known as pus cells, 92 DENTAL PATHOLOGY AND THERAPEUTICS. Is pus to be considered as dead, waste matter? Ans. All pus is not so considered. Pus is composed of living as well as dead matter. Is the suppurative process always and only a destructive process of inflammation ? Ans. It may be, and usually is, both destruc- tive and reconstructive. Reconstructive agen- cies perpetually antagonize the destructive agencies of disease. What is the cause of the swelling when pus forms in the body of an organ or tissue ? Ans. The exudation from the blood vessels. How does this differ from the swelling noticed in the second stage of the inflammatory pro- cesses ? Ans. The swelling of the second stage is caused by the expansion and fullness of the blood vessels supplying the inflamed part. In the suppurative stage it is caused by transuda- tion and infiltration of the contents of the ves- sels into the surrounding tissue. What is the cause of the severe pain felt in the pus-forming processes ? Ans. The pressure of the infiltrated material and of gases formed by decomposition. What are the symptoms of pus-formation ? Ans. A lessening of the pain, a softening of the part, fluctuation when touched by the finger, DENTAT> PATHOLOGY AND THERAPEUTICS. 93 and if the area of supperation is of large extent so as to affect the oreneral system inducing a febrile condition, supperation may be attended with chills. If the suppurating area is limited and comparatively insignificant, no chill is ex- perienced. What is ulceration ? Ans. Suppuration on the surface of an organ or tissue. What is abscess ? Ans. Suppuration in the body of a tissue. What becomes of pus formed within the body of a tissue ? Ans. If in small amount, it may be absorbed and pass off with the general waste of the tissues and resolution may supervene. If in larger quantity, there is formed a fibrous sack to restrain the pus from infiltrating into the surrounding tissues, then a tube is formed of like tissue as the sack, leading out from the sack and opening on the surface. {See alveolar abscess) What is the tube and the opening called? Ans. The tube is called 2l fistulous tube or canal, and the opening, a sinus. May ulceration be deep seated ? Ans. It may when considerable portions of tissue intervening between the suppurating 94 DENTAL PATHOLOGT AND THERAPEUTICS. area and the external surface becomes broken down. [See deep seated ulceration.) How is the work of repair accomplished ? Ans. By the embr3'onic cells prolificated in the surrounding healthy tissue, excited into action by the destructive agencies manifest in the intiammatory processes. What would inevitably be the result if recon- structive agencies were not actively at work during the process of pus-formation ? Ans. Death of the inflamed organ or tissue, and possibly somatic death. Gangrene — Define i^ Ans. Death of a soft tissue in a body without loss of substance. What is the difference between death of a tissue by suppuration and death by gangrene? Ans. The former is death of tissue particle by particle, accompanied by waste of substance, called molecular death. The latter is death of tissue in a body without waste of substance. How is gangrene produced ? Ans. By a sudden cutting off of nutrition by inJlammato?y stasis in the congestive stage of the inflammatory processes. Give examples of gangrene occuring in ■ dental practice ? Ans. Gangrene of the gum by a careless handlino- of arsenious acid, and o^ano-rene of DENTAL PATHOLOGY AND THERAPEUTICS. 95 the pulp by the action of arsenic applied to devitalize it, and gangrene accompanying ne- crosis of the alveolar processes. Does a tooth pulp die throughout its entire body at once ? Ans. It does not. It dies at the point of contact with the arsenic first; then death progres- ses gradually toward the parts remote. What two theories are prevalent concerning the process of death of the pulp by arsenic ? Ans. One, that it is caused by strangulation of the blood vessels at the point of entrance to the root canal; the other, that it enters into the circulation as an irritant poison. State objections to these theories ? Ans. If strangulation should take place the pulp would die at once, circulation being cut off from the whole body of the pulp; and in the other case, if arsenic entered into the circulation the rapidity of the circulation during inflamma- tion would speedily accomplish the same result. Such results do not correspond with facts as to the gradual death of the pulp, requiring con- siderable time and proceeding gradually from the point of exposure to its apical entrance. What is the theory taught here? Ans. That death of the pulp is caused by thrombosis. What is thrombosis ? 96 DENTAL PATHOLOGY AND THER APEUTtCS. Ans. The formation of a clot of blood within the blood vessels, increasing in extent back toward the heart, until it meets a current y ot blood in some anastomosing- vessel, strong- enough to break up the clot and remove it. Where is this breaking up of the thrombus likely lo take place ? Ans. Just outside the apical foramen. Are the hard tissues, bone, cementum and dentine subject to the same inflammatory pro- cesses as the soft tissues ? Ans. As inflammation can pertain only to mobile, organic and vitalized matter, the in- flammatory processes are not precisely the same in the hard as in the soft tissues, because the cell elements of the hard tissues are re- \/ strained in their ameboid movements by the immobility of the inorganic material to which they are intimately and mysteriously related. Furthermore, the hard tissues are nourished, not by a cu^culating fluid in rapid current, but by an interchange of fluids carried on by the slow process of absorption. Hence, the inflamma- tory processes are slow in becoming establish- ed and by their concealment are elusive of in- vestigation. Is enamel subject to inflammation ? ^ Ans. Enamel having no z^zV^a;/ tissue, imflam- matory processes in enamel are impossible. ' ■— . fiy\/^v\juAM--^--^ -C^- DENTAI. l'A'nroi.O(;Y AND Tit Kl< A PEUTICS. 97 How does inflammation manifest itself in bone? Ans. By pain, swelling of its organic sub- stance, tumefaction, suppuration, molecular waste and reconstruction of tissue, necrosis and exfoliation . To what part of the tissue do the active pro- cesses pertain ? Ans. To the periosteum covering the bone externally, to the bone corpuscles and to the medullary membrane lining the cancelli and the Haversian canals. When nutrition of bone is arrested by the inflammatory process in what condition is the body of the bone found? Ans. In a necrosed condition. What is the manifestation of inflammation in cementum ? Ans. It manifests itself in the peridental membrane which forms and nourishes the cementum, and in the cell life of the lacunae. ' '^ JDoes inflammation of this tissue cause pain ? Ans. Not continuous pain; but when in- flamed it becomes acutely sensitive to the touch; it is seldom, if ever, recognized apart from the diseased conditions of the root mem- brane, except at the necks of such teeth as are denuded of that membrane. How does inflammation manifest itself in dentine ? 98 DENTAL PATHOLOGY AND THERAPEUTICS. 2 Ans. It is manifest in the reticulum, which unites tne terminal ends of the dentinal fibrilli and in the fibrilli themselves. How is this changed condition of dentine designated ? Ans. It is called sensitive dentine. When the vital portions of the cementum and the dentine are destroyed, what is dentine so affected called ? Ans. Necrosed dentine. Can there be necrosis of the dentine while the cementum is alive ? Ans. It is scarcely possible. Can there be necrosis of the dentine without the death of the fibrilli ? Ans. The dentine may be demineralized but not necrosed. VVhat is the process of softening of hard tissues by inflammation ? Ans. While the body of the hard tissue is such that it cannot swell as does soft tissue, the lacunal cells, the medullary membrane and the fibrilli of the dentine expand by inflamma- tion at the expense of the mineral portions, thus the relative proportions of animal and mineral substance are not the same as in normal tissue. When the suppurative process appears in bone what is it called? DENTAL PATHOLOGY AND THERAPEUTICS. 99 Ans, Caries or ulceration of bone. What pathological and physiological pro- cesses are manifested in caries ? Ans. A formation of pus covering the carious portion, a prolification of bone cells and the organization of a granular tissue. What is the purpose of this granular tissue? Ans. It is organized for reparation and restoration of lost tissue. Is there any process analagous to it in the decay of dentine ? Ans. There is not; hence it should not be called ''dental caries.'' What is sloughing ? Ans. It is that process by Avhich a portion of soft dead tissue is separated from the living tissue. ^ What is the slough of soft tissue called ? Ans. Sphacelus. What is the bone thus separated called ? Ans. If in considerable body it is called, sequestrum; if in small fragment it is called spiculum, pi. spicula. By what process is sloughing produced? Ans. Sloughing is produced by two differ- ent processes; one pathological, and the other physiological. 100 DENTAL PATHOLOGY AND THERAPEUTICS. Describe each. Ans. The pathological, consists in a forma- tion of pus by the breaking up of tissue along the line of contact of the living with the dead. The physiological, consists in a process of ab- sorption of the living tissue along the line of contact, thus breaking the continuity. Does the dead tissue of dentine ever ex- foliate like other necrosed tissue ? Ans. It does not. .ETIOLOGY. Of what does aetiology treat ? Ans. It treats of the causes of disease. How are diseases classified setiologically ? Ans. Into idiopathic and symptomatic; the former class are such as cannot be traced to any known cause; the latter, such as can be traced by symptoms or otherwise, to a cause. Name the two divisions of causes. Ans. Predisposing and exciting. What is understood by a prediposing cause ? Ans. Any pre-existing bodily condition, functional habitude, peculiarity of internal struc- ture or external form, which creates a tendency to disease, or renders favorable its develop- ment. What are recognized as exciting causes ? DENTAL PATirOLOGY AND THERAPEUTICS. 101 Ans. Causes which immediately precede the development of disease and operate to pro- duce it. What is the great and well nigh universally prevalent dental dis.ease ? Ans. The wasting of tooth substance by decay. Dental Decay. What are the most noticable features of den- tal decay?. Ans. 1st, A solution of enamel at a point on the tooth least exposed to friction and favor- able for the retention of foreign substances. 2nd, A solution of the mineral portion of the dentine at the bottom of the concavity formed by the wasting of the enamel. 3rd, A dissolving or a crumbling out of the animal or organic portion of the dentine. What natural causes or agencies operate to disintegrate lime formations ? Ans. All lime-rock formations and exposed bones are slowly disintegrated by atmospheric agencies alone. By what artificial agencies may the disinte- gration and solution be greatly accelerated ? Ans. By acids. Are both these agencies operative in the mouth, and from what sources ? 102 DENTAL PATHOLOGY AND THfeRAPEUTlCS. Ans. Both are present and operative In the mouth. The atmosphere, by inhalation; and acids, produced by chemical decomposition of food remaining between or about the necks of teeth, or resulting from morbid condition of the stomach or the salivary and mucous glands. What acid is formed in the mouth by decom- position of vegetable substances ? Ans. Acetic. What by gastric and glandular disturbances ? Ans. Hydrochloric and lactic. What chemical fact concerning the action of acids, favors the localized and penetrating character of the cavities formed in the teeth ? Ans. That these acids are the most active \./ in iJoQJ^ascenl state, thus wasting their strength in the immediate locality where they are generated. The enamel having been penetrated, how is the mineral portion of dentine removed ? Ans. By the same agencies as dissolved the enamel, with the aid of the breaking up process of mineral tissue by the expansion of animal tissue when inflamed, [See softening of bone.) What is the process of the destruction of the organic tissue remainingr? Ans. Organic tissue, both animal and veg- etable, is destroyed by the combined action of %4~A^Lo^ DENTAL PATHOLOGY AND THERAPEUTICS. 128 protect the cavity; — other temporary stopping may be used. This may remain for from twenty-four to forty-eight hours, and if the stopping does not loosen, and it is a case from which, because of the pain of excavating, the pulp was not completely exposed, the arsenic may remain for a week. After its removal, and before the cavity becomes filled with saliva, , / apply dialysed iron to nutralize the arsenic and secure the surrounding tissues against harm. Removal of the tissue is by mechanical and chemical means. It is better to wait for a day or two and until the dead tissue becomes emptied of its watery portion, and its fibrillous attachments to the dentine become broken by partial disorganization of tissue. From the straight round roots it may then be removed in a body. From the flat roots of the molars this is impossible. Decomposition is the only siu^e method of removal in such cases. If in the lower molars, lacto-pepsin may be employed as a digester of the fragments of pulp tissue re- maining in the roots; also the carb. of soda if carefully applied. After having done all, there is no certain removal of dead tissue from all the molar roots except by the natural process of decomposition, and no perfectly safe closure of the apical foramen, until nature closes it by a deposit of cementum. 124 DENTAL PATHOLOGY AND THERAPEUTICS. Congestion of the Pulp. Treatment — If the throbbing pain of con- gestion has been experienced, extirpate at once. If quited for a season, there is the highest probabihty that after the best of treatment and capping, within six to eighteen months the pulp will be found dead or needing devitali- zation. It should be remembered that there is no organ of the body that has such a feeble hold on life as a dental pulp, — even its vital tendencies are toward obliteration. Pain after Filling. Causes. 1st, The nerve fibrils may have been in such a state of irritation when the filling was inserted that they developed an inflam- mation in the pulp. 2nd, The cavity of decay may have extend- ed so near to the pulp that a metal filling would conduct thermal changes and produce pulp in- flammation . 3rd, The cavity may have been free from sensation when filled, and apparently have firm walls although the pulp was in a suppurative condition. 4th, If the tooth pulp died a spontaneous death it might have been free from pain so long as the cavity was open; but when filled the diseased condition of the alveolo-dental mem- brane became manifest. >S