THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA LOS ANGELES - , l L : MANUAL OPERATIVE TECHNICS A Practical Treatise on the Elements of Operative Dentistry. By THOMAS B. WBBJTS, >. D. S. Professor of Operative Dentistry and Dental Anatomy in the College of Dentistry Department of Medicine, University of Minnesota. PUBLISHED BY H. D. JUST I <&. SON, CHICAGO, ILLINOIS, U. S. A. Copyrighted, .1894. PREFACE. It is not my object to present in these pages an exhaustive work on operative procedure, or to conflict in any way with exist- ing text-books on the subject, which, so far as the author is aware, cover the whole ground over which the student will travel in his three years' course of study. The suggestions as to what may be done and how the Subject may best be presented, are the result of the experience of the author and his confreres. Experience has shown that to attempt to indicate to students what and how much they shall learn of operative procedure from existing text-books, to enable them to in- telligently perform practical operations, involves an immense amount of labor and an expenditure of time which can be better employed in some other direction. I have attempted to present in a compact form such funda- mental knowledge of operative dentistry as every student should possess before attempting to practice upon patients, and to direct him how to perform the various operations in the technic labora- tory. If we may judge by the large number of colleges which an- nounce technic courses in their catalogues, educators all over the country are alive to the importance of a systematic course of manual training which shall give a more thorough knowledge of the teeth and the principles which underlie all operations upon fhem. These are the conditions prompting the attempt to outline a course and to present a succinct statement of principles, which shall be a primer on operative dentistry for the student, his hand- book and constant reference while performing the operations re- quired. The desire to be helpful to both teacher and student has been the constant motive, and I hope that the object may be real- ized, and that the principles are so represented that all teachers may use them as a basis for their own particular methods. T. E. W. INTRODUCTORY. " New times need a new system." " To prevent going backward we must work on the line which goes forward." In the early history of dentistry the young men who received their training from the best practitioners were, by much practice in the laboratory, of the purely mechanical or technical, taught to be "handy," but with the increasing demand for a more general scientific knowledge, there grew a tendency to platform instruc- tion an extension of didactic work at the expense of the practical. In many instances this resulted in a cramming of the head which left too little time for training the hand. There is no escaping the truth of the relations existing be- tween the mind and the hand. Some one has called the hand the moral rudder, the balance wheel of the mind. Certain it is that what the hand is to execute is originated in the mind ; then through the eye, the mind directs the hand. Simultaneous train- ing of the mind, the eye, and the hand is the underlying principle of the various systems of manual training, to which the teaching of technics in dental colleges is analagous. Operative technics is generally understood to apply to that part of the instruction which is obtained by operations upon teeth out of the mouth. As this practice exercises the mind and the eyes, and increases the dexterity of the hand, it must be allowed that its governing principles are the same as those of manual training. That the dental student should become "brandy" by doing some suitable hand work, is not only desirable but necessary. The best teachers recognize that the child gains a much better under- standing by seeing and handling and doing, than by merely hear- ing and remembering. They recognize also that systematic training of the hands is not antagonistic to mental growth, but assists it. There are two kinds of knowledge what we know through our own experience, and what we know through the experience of others. What is told us is another's ; it rests on a different basis 2 INTRODUCTORY. from that which we have gained by our own experience. Does the knowledge of the existence of the ant, or the bee, or the various winged creatures of the woods make an entomologist or a natural- ist ? Is a man a machinist because he has learned the parts of the steam engine, and can define axle, lever, plane, and screw ? Should a man be called a dentist because he can name the teeth, bones, mus- cles and nerves, describe the making of amalgams, or detail the best method of filling a tooth ? No, not even if he can rehearse all his teacher has repeated to him. A purely mental acquirement is a theorem, and a' theorem is a demonstrable proposition. Whether it may be proved is always a question until the act of doing solves the doubt. In the progress of knowledge, practice ever precedes theory. That it is necessary for the dental student to possess more knowl- edge than can be gained from lectures and text-books, of the form, structure, and diseases of the teeth, of the properties of materials, and of the forms and uses of instruments, as well as dexterity in handling them, before he be allowed to operate for patients, is now generally acknowledged. Prof. G. V. Black, recognizing that the practical uses of any science or branch of knowledge are of higher importance than the purely intellectual, sounded a distinct note for advance, in a paper presented before the Chicago Odontological Society in June, 1888. He proposed a course in operative technics, which, without limiting any part of the instruction in operative dentistry as usu- ally given, would broaden and improve that teaching, which would, in fact, form the basis for didactic and clinical instruction. He says: "Students shall be taught the nature and physical qualities of the teeth upon which they are to operate, of the materials they are to use, and of the instruments by means of which they are to use them. This I would do in a series of object lessons, by having stu- dents handle teeth and study their forms and examine enamel and dentine by cutting them with instruments; manipulate the material used for fillings, study and practice the use of instruments, and learn the tests for perfect manipulation." This is the foundation of the courses in operative technics in the several colleges where that plan of teaching is in operation. A course modeled on these outlines was instituted in the Chi- cago College of Dental Surgery for the session of 1888-9. The Dental College, Department of Medicine, of the University of INTRO D UCTOR Y. 3 Minnesota adopted a similar course the following year. Others fol- lowed, until at the present time about one-fourth of the colleges of the United States have systematic courses in operative technics. Besides the outlines already referred to, and the paper by Dr. D. M. Cattell before the World's Columbian Dental Congress, com- paratively little has been written; nothing so far as the writer is aware which would serve as a text or reference book for teachers and students has been published. To meet this demand is the present object. The difficulty of presenting any form which in its entirety could be adopted by all teachers, is appreciated, but an endeavor will be made to present a course which shall embrace the principles which underlie operative procedure. It is generally conceded that a fa- miliarity with the organs to be operated upon should take prece- dence of all else; consequently dental anatomy will be given first place. The existence of so good a text-book of dental anatomy as that of Prof. Black's removes the necessity of giving more than a few suggestions as to how it should be studied and the manner of presenting the subject to classes. Experience has shown that while text-books, models, charts, etc., are indispensable, these are not all that is necessary. The teacher must study each class, modify the course to suit their needs, and present it in short, terse explanations. The introduction of these explanations at intervals gives relief from the tedium of handling and cutting teeth and all other purely manual exercises, as well as carrying out the object of simultaneous development of the mind, the eyes and the hands. The equipment of the technic laboratory with double curtains, a screen and stereopticon, ready at a moment's notice to present images of the teeth and their structure, has proved both useful and instructive. These pictures, produced by photography, are more accurate, and the method of presentation seems to interest the student and hold his attention better than charts or drawings do. The syllabus presented does not include pathology or thera- peutics to any greater extent than is necessary to elucidate the points where they modify or govern operative procedure. The object is to fill the time allotted to this work with the what and the how, leaving much of the why for subsequent in- struction. CHAPTER I. OUTLINE OF COURSE. OUTLINE OF THE COURSE BY DIVISIONS. ("Terminology and nomenclature. TT-V i- J Notation. Descriptive, < Ff)rm I. Dental Anatomy. \ Macroscopic. Structural, j j Microscopic. TSteel, its composition and properties. TT T t I Shaping, tempering and finishing. I Classification according to form and uses. I Action or use for each form. /-Gaining entrance to canals. r . Removal of pulps. j Cleansing and preparing canals. (^Filling canals. TV ~ . . ( Classification from location and causes. } Preparation on principles governing. f~ . ( Treatment and Protection. (Conservative j capping V. Pulp Treatment. r? ,. , \Surgical devitalization. L ( Devitalization by drugs. (-Characteristics and composition. VI. Filling materials. J f""j IT <. j Introduction into cavities. ^Finishing fillings. DESCRIPTIVE ANATOMY. TERMINOLOGY AND NOMENCLATURE. Recitations of first two chapters in Black's Dental Anatomy. Each student is furnished two brass rings about two inches in di- ameter; one bearing the teeth of one side, superior; the other the teeth on one side, inferior. Upon these teeth he will locate the dif- ferent markings, as angle, apex, crown, root, pit, sulcus, groove etc. Notation. The following notation is one which furnishes the simplest form of expression for any given tooth. It was first introduced by Dr. Corydon Palmer. The use of the Roman 6 NOTATION. numerals to designate the deciduous teeth was suggested by Dr, W. P. Dickinson. DECIDUOUS TEETH. PERMANENT TEETH. V IV III II I I II III IV V 876 5 4 3 21 12345678 V IV III II I I II III IV V 87654321 12345 678 EXAMPLES. Right superior central incisor, permanent, 1 I Left " first bicuspid, " 14 Right inferior second molar, deciduous, V | The use of this system saves much time in labeling blocks or drawings and in making records. It will be used when convenient in this article. Form. Recitation upon each class of teeth. Selection of one or more of each class. Indicating upon these their.chief markings. Drawing or modeling each tooth. First, recitation is heard upon the superior incisors. Follow- ing the recitation, the class make practical application of the infor- mation gained from the book, by selecting from a miscellaneous lot of teeth, one or more specimens of 1 | 1, and 2 2, pointing out and naming their crowns, roots, gingival line, surfaces, angles, grooves, ridges, and any departure from the normal. As it seems to impress upon the student's mind the outline of the tooth, the sections for printing are cut while on the study of the form of that tooth Finally, drawings should be made of the labial, lingual, and mesial surfaces of 1 and 2; or what is better, model each tooth in clay. These last exercises must be from memory. This plan of study is carried out upon all the teeth, deciduous and permanent. Arrangement. All the permanent teeth are now selected and arranged after nature, in a dummy articulator. (See Fig. 1.) This exercise demonstrates the students knowledge of arrange- ment. CUTTING SECTIONS. 7 STRUCTURAL ANATOMY. Macroscopic. Cutting sections, longitudinal and transverse. Printing silhouettes with these sections. Studying form, location and size of pulp chamber and canals; form and thickness of enamel, and relative proportion of crown and root. The importance and advantage of this work cannot easily be overestimated. It is the first direct contact that the student has with teeth. By cutting them he is taught the difference in the character of enamel and dentine. It gives training in the use of FIG. 1. broaches. It fixes in his mind the forms of the teeth and the rela- tive form, area, and location of their component parts. It teaches him the system of notation, and, best of all, it cultivates habits of neatness and order. At the same time it should not be extended until it becomes irksome, and it should not trench upon time re- quired for equally important work. As the result of the author's experience, he has introduced several modifications in the work 8 CUTTING SECTIONS. which he believes gives the student the greatest benefit in the shortest possible time. The teacher should collect, examine and classify the teeth for this work; he should furnish the students with teeth and the blocks for mounting, and he should retain the sections. From this collec- tion, students of each year will have opportunity to make a much better line of prints than if they were restricted to the cuttings of FIG, I. A one winter. T-hese sections are filed in trays, holding six blocks, which are incased in filing boxes holding twelve trays. Each student should cut a section of at least one aspect of every tooth, and make prints of every aspect of six teeth of each denomination, in the book provided, besides a duplicate sheet of each leaf for the teacher. The teacher should cut on every section the relief line showing the enamel. This relief line gives several advantages: first, it shows the relative proportion of crown and root; second, it shows the form and thickness of enamel upon different parts of the crown MARKING BLOCKS. 9 and, third, it shows the relative thickness of enamel upon the differ- ent teeth. It is cut with a minim wheel bur, which removes the stratum granulosum. The student needs for this work: 1 stick Am. Ex. sealing wax, 1 half round file, 8 inch, bastard cut, medium coarse, 1 bench vise, 1 alcohol lamp, 1 jeweler's hack saw, with 12 saw blades, 1 wax spatula. 1 excelsior ink pad. 1 rubber pad 3 in. x 6 in. x ^ in. 1 book for printing, open at end. Leaves ruled as in Figs. 6 and 7. Some fine canal explorers, some fine sandpaper, an old tooth- brush and some cotton cloth. To insure uniformity, these materials should be selected by the teacher and supplied from the clerk's desk at the college. The teacher should provide the teeth for cutting, and the blocks for mounting; also tablets of paper same texture, size and ruling as books; and some tablets of similar paper for experimental printing. In marking the blocks bearing teeth which are to be cut lon- gitudinally, the abbreviations, la-labial, b-buccal, li-lingual, m-me- 1-2-3 sial and d-distal, may be used. The being conical,are usually 1 - & -o cut to the central axis. A tooth cut mesio-distally would show a la. or li. aspect, and one cut labio- lingually would show a m. or d. aspect; but to avoid confusion we will label all sections cut in the manner first mentioned la. and those mentioned second, m. If transverse sections are printed upon pages ruled as in Fig. 7, no marking is necessary further than the notation. The blocks bearing superior teeth should have figure denoting tooth in upper left corner, and letter or abbreviation denoting as- pect, in upper right corner. See Fig. 2. Those for inferior teeth should have figure denoting tooth in lower left corner, and letter or abbreviation in lower right cor- ner. See Fig. 3. As mentioned before it is an advantage to cut the sections of each tooth immediately after reciting upon the form of that tooth. Directions for cutting of one will stand for all of the teeth. 10 MOUNTING AND FILING. Let each student select from a miscellaneous lot of teeth a superior central, every second student cuts la. aspect, the alternates cutting m. aspect. Fasten upon block with sealing wax, see Fig. 4 and Fig. 5. Fix block in vise ; holding the file horizontally at an angle of 45 with long axis of tooth, cut rootward until pulp chamber is penetrated. Pass a fine explorer through this opening into the canal and through the apical foramen ; the explorer may be left in canal and cutting resumed until the canal is exposed in its entire length, when it is removed and the surface of section made as nearly plane as the direction of the canal will permit. I LA I M FIG.2. FIG, 3, NOTE. Blocks are ij 62 63 65 66 67 88 s 72 73 74 75 76 77 78 79 81 80 ,38 DRILLS FINISHING BURS. Drills. These instruments are now seldom used except in the dental engine. In the technic laboratory they are used in a revolv- ing head socket handle. Fig. 82. The Century Dictionary gives under the definition of "drills ' ' not only " dental burs " but all side cutting instruments or " reamers "; under a finer definition we may consider drills as instruments for boring holes, and reamers, or side cutting instruments, as agents for enlarging openings already existing. Many dental burs have the ability to act both ways. The instruments shown in Figs. 83-86, designed for working in root canals, illustrate these three types. Fig. 83 is a drill, Figs. 84 and 85 are reamers. Fig 86 is both drill and reamer. The various forms of drills are illustrated in Fig. 87. The several forms of cavity burs are seen in Figs. 88-97. The round, Fig. 88; the oval, Fig. 89; the pear, Fig. 90; the bud, Fig. 91, and the pointed fissure, Fig. 92, belonging to one family, and cut the same, i.e., leave the same kind of surface, as convex edged, round or pointed, spoon excavators. The cone, Fig. 93; the inverted cone, Fig. 94; the wheel, Fig. 95, and the square or flat end fissure, Fig. 96, are of another family, and may be used for the same kind of cutting as the square end excavators, /. e. , where plane surfaces and angles are required. INSTRUMENTS FOR FINISHING FILLINGS. Finishing Burs. These are of the same forms as cavity burs, but are larger and finer cut. They are, in fact, single cut, revolv- ing files. There is a newer form which is double cut, made in two forms, round and pear-shaped. Files. The file is a tool too well known to need special description. The introduction of the dental engine, with its diverse armament of burs, has almost entirely abolished the use of files except for the finishing of fillings. The separating file is still useful in some forms of cavity preparation. The so-called "flexo files" are the favorites, being sufficiently soft to bend with- out breaking. The "flexo" separating file is shown in Fig. 98. The chief use of the finishing file is at the cervical margin of fillings on the proximate surfaces. Those known as file trimmers are made with handles similar to those of excavators and sealers, Fig. 99. Those known as files have handles like the " flexo" fin- ishing file shown in Fig. 100, or like the one shown in Fig. 101. Many are made double end, Fig. 102. Of the many forms only a few of the most useful will be illustrated, Fig. 103. S3 84 85 86 n 87 A w 89 90 91 08 93 9i 95 96 100 101 A 99 1O2 103 SA WS TRIMMERS DISKS. 29 Saws. These are used in separating and in trimming the cervical margins of fillings. They are generally used in a frame, Fig. 104, and are made with teeth on one edge, Fig. 104 a, or with teeth on both edges, Fig. 104 b. Flexo files are also made for the saw frame. Trimmers. These instruments are decigned for shaving or paring the surfaces of proximate fillings. They- have very thin lancet-like or chisel-like blades. The chief forms are seen in Fig. 105. The sickle sealers, Fig. 77, if sharpened, make very effective trimmers. Grinding Instruments. These are in the form of wheels, disks and points. Wheels are simply small grindstones, of varying thickness, varying in diameter from one-fourth of an inch to an inch. The great variety of disks and points are shown in Figs. 106 and 107. They are made of corrunduro, Arkansas, Scotch and Hindostan stones, and of copper charged with diamond dust. Corrundum is the native crystalline oxide of aluminum; in hardness it ranks next to the diamond. The purest forms of cor- rundum are the gems, sapphire, Oriental amethyst, ruby, and Oriental topaz. It is the darker, opaque varieties which are pul- verized for grinding purposes. In the ordinary corrundum disks and points it is combined with shellac, while in the hard rubber and corrundum- combination it is incorporated into the rubber before vulcanizing. A newer form is "carborundum," which, being vitrified, cuts well and wears slowly. Disks and points of Arkansas, Scotch and Hindostan stones are used in the finer grinding for finishing enamel margins and fillings. The copper and diamond disks and points are used in separating, cutting enamel, and finishing fillings. Disks are made of emery, sand, garnet, and cuttle fish paper. All but the cuttle fish, which is very fine, grade from coarse to fine. Disks of these materials are of three forms: plain, depressed, and safe center, Fig. 108. The last two are in three sizes only, while the plain ones range from three-sixteenths of an inch to an inch in diameter. Cloth and paper strips of the same grits as those on paper disks, are used for finishing the proximate surfaces of fillings. Short pieces of these strips are used in a pcrte for the engine for polishing other surfaces, Fig. 109. Disks for carrying such polishing powders as pumice, silex, chalk, oxide of tin, and rouge are made of celluloid, felt, and soft rubber. Points for the same purposes are made of wood, leather, felt, and soft rubber. These are useful in polishing teeth and fillings. Instruments for carrying disks and points are illustrated in Fig. 109^. a\ 106 107 1O4 L 108 109 ii SPA TULA S PL UGGERS. 81 INSTRUMENTS FOR INTRODUCING AND CONDENSING FILLING MATERIALS. Spatulas. These are defined as instruments "having broad, flat blades with unsharpened edges, used for spreading, smoothing, scraping up, or stirring substances." In operative procedure they are used for mixing cements, introducing the mass into the cavity, and smoothing the filling. With the addition of a round point, a ball end point, and a lancet trimmer, cements may be manipulated entirely with spatulas, or spatula-like instruments. The different forms are illustrated in Figs. 110-113. The ball end and the round points are shown in Figs. 114 and 115. Some forms of noncorrosive instruments, made of platinum, are seen in Figs. 115-117. Pluggers. This is the name given to instruments for the con- densation of gold and other filling materials. Condensing instru- ments are for the purpose of conveying force or impact from the hand or mallet to points inaccessible to the hand or mallat. The solidity, homogeneity, or density of fillings is attained in one of three ways. By introducing the material in a plastic condition and allowing it to harden ; by wedging or interweaving folds or rolls, made from very thin sheets of metal ; or by welding small pieces of metal together in the cavity. Each of these methods requires instruments peculiar to itself. Instruments described for the introduction of cements with the addition of the serrated points, Figs. 118 and 119, comprise the necessary forms for the introduction of amalgam, gutta-percha and zinc plastics. Tin and noncohesive gold are introduced by wedging or inter- digitation j instruments must have wedge-shaped points, and all serrations must be sharp and deep. In Figs. 120-129, are f shown the several forms of points, also the angles and curves in the shanks which are necessary to bring the points into direct action upon all surfaces. These instruments are used chiefly by hand pressure. Cohesive gold is introduced in small pieces, welded, or fast- ened together in the cavity. To accomplish this, the points of in- struments must have "faces," which will bring the surfaces of the gold into perfect contact. These faces are either flat or convex, with fine, shallow serrations. Pluggers used with the mallet have handles like Fig. 130. The faces have various outlines, circular oval, square, oblong, pear-shaped and triangular. The points are A 114 I 111 112 113 114 115 116 117 118 119 O 147 148 149 150 151 153 PLUGGER POINTS. 33 plain, as illustrated in Figs. 130-132, or foot-shaped, as in Figs. 133-138. The shanks of pluggers have various styles of curves, the single curve, Fig. 132, the bayonet, Fig. 127, and the cork- screw, Fig. 129. Curves in the shanks of pluggers are for the same purpose as in other instruments, /. e., to bring the point into direct action upon surfaces inaccessible to straight instruments. Angles in shanks do not divert the force. If a plate of steel, shaped like Fig. 139, is struck with a hammer at A, or at any point on the end between A and B, the force will be delivered from C, in the direc- tion indicated by the arrow, /. k 2d rz 4th 3d 1st 7th 6th 5th brittle 8th ra ink nk 2d n 7th 4th 1st 6th 3d 8th brittle 5th ra ink nk 1st rai 5th ' 2d ' 3d ' 4th ' 6th ik 1st ra 5th 2d 3d 4th 6th ak Tin. Copper Gold Zinc Platinum . . . Cadmium . . . Antimony. . . Palladium. . . NOTE. The electrical state of all the metals except mercury is positive. 78 ALLOYS. SOLUBILITY. MERCURY Soluble in dilute nitric, and hot sulphuric acid. SILVER In nitric and hot, strong sulphuric acid. COPPER In hot mineral acids; slowly attacked in air and moisture by vegetable acids, alkalies, and saline solutions. GOLD In aqua regia; not affected by single acids or alkalies. ZINC In dilute acids, and solutions of the alkaline hydrates. PLATINUM Is dissolved slowly in aqua regia. OXIDATION OR CORROSION. MERCURY Not affected by air or moisture. SILVER Not acted upon by air or water; but readily by sul- phuretted hydrogen. TIN Oxidizes very slowly. COPPER In moist air becomes coated with a green carbonate; is tarnished by sulphuretted hydrogen. GOLD Unaffected by air, water or sulphur. ZINC Tarnishes slowly; is coated with carbonate in moist air. PLATINUM Unaffected by air or water. CADMIUM Tarnishes slowly in air and sulphuretted hydrogen. ANTIMONY Oxidizes badly when amalgamated. PALLADIUM Does not oxidize easily, but is acted upon by iodine. COMBINATION WITH MERCURY. SILVER Forms definite crystalline chemical compounds with mercury. TIN Unites with mercury in atomic proportions, forming a weak crystalline compound. (Kirk). Mitchell says it does not. COPPER Does not form definite compounds with mercury; but in the form of crystals, is dissolved by it in varying proportions. GOLD Is dissolved by mercury in all proportions; but does not form a definite atomic compound. ZINC Unites with mercury in atomic proportions. PLATINUM Only unites with mercury when reduced to a spongy condition. PALLADIUM The union with mercury is probably chemical. COMBINATION WITH OTHER METALS. MERCURY Dissolves all metals but iron. SILVER Has affinity for platinum. TIN Has affinity for gold and platinum. f PROPERTIES OF METALS. 7'J COPPER Unites with zinc in all proportions; and in certain proportions forms definite compounds. GOLD Unites with silver in any proportion; and is rendered very brittle by the least trace of antimony, palladium or lead. ZINC Unites in all proportions with gold and tin; forms chemical compounds with platinum. PLATINUM Unites in definite proportions with silver and cadmium. NAME. MERCURY. SILVER. TIN. COPPER. GOLD. ZINC. PLATINUM. CADMIUM. ANTIMONY. PALLADIUM. COLOR. Silver white, lustrous. Pure white, lustrous. White, brilliant. Red. Yellow,lustrous. Bluish white. White, tinged with blue. White, with blue tinge. Bluish white. White. CONSISTENCY. Fluid at ordinary temperatures. Soft between Gold and Copper. Soft. Soft, hardens by hammering. Soft, hammering or burnishing har- dens. Brittle unless heat- ed and rolled. A little softer than copper. Between tin and zinc. Hard; brittle. Hard as platinum. CRYSTALLIZATION. * Spherical above 39 F. Regular system. Quadratic system. Regular system. Regular system. Rhombic system. Practically amor- phous. Regular octahe- drons. Rhombic system. Regular system. PROPERTIES IMPARTED TO AN ALLOY BY THE VARIOUS METALS. MERCURY, being the controlling metal, imparts its spherical tendency to the amalgamated mass; especially in those alloys which are "solutions," or "mechanical mixtures." This tendency is greater with those metals having a low fusing point, cooling slowly, and when amalgamated setting slowly, as tin; and less with those which melt at a higher temperature, cool quickly, and set quickly when amalgamated, as silver and copper. SILVER controls hardening or setting because of its crystalline form and chemical affinity for mercury; it maintains the bulk in- *" Regular crystals expand equally in all directions; rhombic and quadratic ores expand differently in different directions." Enc. Brit., Vol. XVI., p. 64. 80 INFLUENCE OF METALS. tegrity of the filling, and should be the largest component of an alloy. The silver sulphide formed by the action of sulphuretted hydrogen is supposed to have prophylactic action against decay. TIN should be next in quantity, because it increases plasticity, prevents discoloration, and reduces conductivity. It also retards setting, reduces edge strength, and favors spheroiding; hence, should not be used in such proportions as to become the controll- ing metal. COPPER diminishes shrinkage, hastens setting, and adds to the present and possibly to the permanent whiteness of the filling. It is also supposed to have greater compatability with tooth sub- stance and pulp tissue than other metals, and has been shown to have antiseptic action. GOLD lessens shrinkage, resists corrosion, increases edge strength, increases smoothness and plasticity, and hastens setting; all these to a greater degree in small quantities than any other metal, 5 to 7 per cent being all that is advantageous to use. ZINC controls shrinkage, hastens setting, improves color, and imparts a peculiar smoothness in mixing. PLATINUM Authorities differ in regard to the influence of this metal; some claiming that it increases setting, hardness, stability, and improves color; while others contend that it imparts no prop- erties which cannot be obtained by a judicious combination of other metals; which seems to be true. CADMIUM having been proven to be dangerous to pulp vitality, should never be used. ANTIMONY blackens so badly that the properties of controlling shrinkage, and increasing plasticity which it imparts, do not seem to be of sufficient advantage to warrant its employment. PALLADIUM does not improve alloys, but amalgamated alone with mercury, furnishes an amalgam which does not shrink or dis- color, but its expense hinders its universal use. It is an open question whether freedom from discoloration is a desirable attribute; it is certainly true that cavity surfaces under leaky fillings which have become coated with a black oxide or sul- phide, have remained free from decay for years. We hold that un- sightliness is the principal objection, unless such chemical com- pounds are formed as will cause wasting of the filling or prove detri- mental to the health of the patient. Since these tables were prepared aluminum has been intro- ALUMINUM. 81 duced as a constituent of amalgam alloys. Its sp. gr. is 2.6; the lightest of the metals. Fusing point, 1300F. Its tenacity, in pro- portion to its weight, is equal to steel. Malleability next to silver. Ductility next to copper. Conductivity about the same as copper. It does not oxidize or corrode and prevents oxidation when com- bined with other metals; but only a small per cent can be com- bined in an alloy. It is not readily acted upon by mercury. In amalgam alloys it is supposed to whiten them and prevent discol- oration. An amalgam is produced by precipitating pure copper, in the form of crystals, from a saturated solution of sulphate of copper into mercury, in which form it is capable of solution in mercury. This precipitation is accomplished by galvanic action or by plac- ing a rod of iron in the solution. The galvanic method is preferred When the solution has been carried to the limit, the mass is put in a wedgewood mortar and triturated thoroughly; the surplus of mercury is removed by squeezing in a chamois skin bag. This process is repeated, resorting to heat to soften the mass, as it be- comes necessary, until amalgamation is complete ; it is then moulded into small ingots and allowed to harden. As this prepa- ration possesses characteristics peculiarly its own it will be consid- ered apart from ordinary amalgams. The qualities which commend amalgams are density, hardness, ease of introduction, and cheapness. The objections to it are. its color, or rather its disposition to discolor, a lack of ductility and tenacity edge strength a tendency to molecular change in harden- ing, a liability to chemical or electrical changes in the mouth, and its conductivity. Compatibility with tooth substance and prophy- lactic action are disputed points. Density and hardness are qualities which all amalgams possess to a degree which enables fillings to withstand all strain and wear to which they are likely to be subjected, and "to receive a perfect finish. Ease of introduction, which is probably its strongest recom- mendation, is liable to abuse, as its peculiarities demand the great- est care in its manipulation. Cavities should be as thoroughly prepared for its reception as for gold. It should be as carefully in- troduced, condensed, and finished as is gold. When this is done its other advantage, cheapness, is greatly modified. Cheapness should be the last quality considered. It is better to fill teeth well 82 PROPERTIES OF AMALGAMS. with amalgam than to allow them to be lost because the patient cannot afford gold, but ordinarily the choice of materials should be based on higher considerations. Color, while classed as an objection, is frequently an advan- tage; an oxidation of the surface having been proved by clinical ex- perience to exert a prophylactic action against decay. Lack of that ductility or tenacity which results in crumbling of the edge next the margins of the cavity, is a fault which can be overcome in cases where enamel margins are strong and cavities can be shaped as in Fig. 190; but where enamel margins are frail or must be shaped as in Fig. 189, few amalgams have sufficient te- nacity edge strength to resist the force of mastication. It is also difficult to insert and finish amalgam perfectly where the enamel bevel is long. Liability to molecular change is the objection most difficult to overcome. Reducing metals to a plastic condition by mercury is somewhat similar to fusing them by heat; in either process, as metals lose their solid form the molecules change their position separate; coming together again as the mass regains its solidity. These are natural conditions over which we have but limited con- trol. Chemical and electrical changes are certain to result when the conditions of the mouth are favorable. A thorough knowledge of chemistry and the intelligent application of its principles, alone can combat this objection. Compatibility and prophylactic action are qualities, which de- pend almost entirely upon chemical action; whether this action ex- erts a good or evil influence depends also upon the recognition and careful observance of chemical laws. Conductivity is an objection which can be overcome in most cases by the insertion of a nonconducting "intermediate." The extent and manner in which its weak points may be over- come has already been stated, except that of molecular change. The results of the many experiments which have been made seem to indicate that the change incident to crystallization must be re- duced to the minimum. First, the alloy must be one which, when amalgamated, crystallizes under the regular system; second, the mass must have a minimum of mercury, or it must be introduced after crystallization has begun. After choosing an alloy in which the change from crystallization is small, the best results are ob- MIXING AMALGAM. 83 tained by expressing all the mercury possible, driving the molecules into the closest possible apposition. In mixing, the smallest amount of mercury should be used which will amalgamate the alloy; the mass should be thoroughly mixed in a mortar, that the mercury may come in contact witfi every particle of the alloy; any surplus mercury may be expressed by squeezing in chamois skin with strong flat nose pliers. The mass should be introduced into the cavity in small pieces, and thoroughly condensed with instruments having convex faces; any surplus mer- cury should be taken up as it appears on the surface; very dry pieces should be used in finishing, warming the instruments if nec- essary. Copper amalgam is prepared for use by slowly heating one of the ingots in an iron spoon until globules of mercury appear upon the surface, when it is triturated in a mortar. The subsequent manipulation is similar to that for other amalgams. In copper amalgam the tendency to molecular change is slight; thus one of the greatest objections to amalgam is overcome. It has also great edge strength. The experiments of bacteriologists show that it has marked antiseptic action. It is easily manipulated and has a bright silvery appearance when finished. In some mouths it turns black and sometimes blackens the surface of all other metallic fill- ings in the mouth as well as the teeth themselves. When it turns black it retains its bulk integrity and preserves the teeth. When it retains its silvery whiteness it wastes away; in some cases the sur- face softens so much that it can be scraped off with the finger nail. This uncertain behavior has led to its abandonment to a great ex- tent. The conclusions seem to be that it is not wise to employ copper amalgam where there are other metallic fillings, or in mouths in which there is much chemical decomposition. The deductions we draw from this study of amalgam are, that considered under the requisites for a filling material, it possesses sufficient density and tenacity to resist attrition and strain, and sufficient edge strength where enamel margins can be properly prepared; that it transmits thermal changes so readily that an "intermediate " is necessary where the tooth is sensitive to such changes; that because of its plastic condition it is very easy to introduce; that it is susceptible to chemical changes to such extent that this tendency must not be ignored, in any case where the elements conducive to such changes exist; that its tendency 84 COPPER AMALGAM TIN. to molecular change must be combated in every way possible; that it is capable of receiving the necessary finish, but that its color and tendency to discolor give results which are neither har- monious, nor a pleasant contrast to tooth color; hence it is not suitable for cavities which are exposed to view. TIN. The qualities of tenacity, ductility, malleability, conductivity, oxidation or corrosion, color and consistency, have been considered in the tables. Tin for filling teeth must be pure. It is prepared for dentists' use by beating or rolling it into foil, which is put up in books of uniform size. The number indicates the weight or thick- ness of a leaf; the numbers are 2, 4, 6, 8, 10, 30, 60 and 120. The heavier numbers only are rolled. For introduction into cavities, strips of the foil are rolled in a napkin, twisted into ropes or folded into ribbons; cylinders are made by rolling the ribbons upon small smooth broaches. It is also prepared for fillings by fixing a round ingot in the lathe and turning off shavings for immediate use. It is claimed that tin is cohesive when prepared in this form. As tin possesses to a limited degree, if at all, the property of cohesion, or welding without heat, its homogeneity depends upon wedging or interdigitation. On this account it can only be employed in cavi- ties of class 1, or of division A, class 2, and in those cavities of division A, class 3, where the marginal ridge is not involved, i. e., cavities must have continuous walls. Density and hardness. Considered under the demands for a filling material we find that tin fulfills the first requisite, density, to only a limited extent, and it is not sufficiently hard to withstand the wear of mastication. Tenacity is lacking to a degree which precludes its use in those cavities where restoration of contour is demanded and it can- not be used in cavities having such enamel bevel as is shown in Fig. 189. Low conductivity. Platinum excepted, tin is the poorest conductor of the metals employed for fillings. For this reason it may be used in those cavities which are so sensitive to thermal changes as to render the use of gold or amalgam unwise. Ease of introduction. With proper instruments, a proper preparation of both the cavity and the material, tin may be intro- duced with much facility into such cavities as are easy of access. Freedom from chemical action. While tin corrodes slightly, PROPERTIES OF TIN. 85 and in some mouths considerably, it is not readily acted upon by the fluids of the mouth. Freedom from molecular change. As the crystallization of tin is not interfered with in its introduction, there is no subsequent change in its bulk integrity, Capability of polish. While a tin filling may be given a highly burnished surface, it does not retain it, because of the softness of the material. Owing to its inherent qualities, tin is somewhat limited in its application. Its use is not indicated for large cavities on occlusal surfaces which are subjected to much wear. Its use is not in- dicated in those cases where lost contour must be restored, or for proximate fillings where its surface might be roughened or dis- turbed by efforts at cleansing with toothpicks. It may be used to advantage in children's teeth and in all cases where the use of gold is not indicated or where it is undesirable to use amalgam. Fig. 231. Cavities must be formed for its reception as is shown in Fig 190}^, a. a., with no more enamel bevel than is absolutely necessary for its protection. Plugger points for the insertion of tin should be wedge shaped, with sharp and deep serrations. When the wedging is complete, the surface may be condensed with convex faced foot pluggers having smoother and shallower serrations. Finally the filling may be burnished, the surplus trimmed off with sharp in- struments, and again burnished. Tin fillings may also be finished with files, emery or sandpaper disks and strips of increasing fine- ness until the proper polish is obtained. Fig. 231 shows the man- ner of placing and condensing cylinders in the cavity. Each cylinder is condensed against those which have preceded it; the 86 INSERTING TIN. operation is continued until only a small space is left in the center; this space is filled by wedging small cylinders into it. Fig. 232 shows the manner of inserting a rope or ribbon by doubling it upon itself. In the insertion of either preparation of tin, the filling is arranged in concentric layers; is solidified by crowding each layer against those which have preceded it, always exerting the force toward the walls of the cavity. The cylinders or folds should project above the walls of the cavity sufficiently to permit of condensing and finishing. GOLD. The tables show that gold possesses tenacity, malleability, ductility, and conductivity in a marked degree; that it does not Fig. 232. oxidize or corrode; that while it is a soft metal, it becomes hard by hammering, rolling, or burnishing; and that its color contrasts more agreeably with the color of the tooth than does any other of the filling materials. Density and hardness. Gold is sufficiently hard and dense to enable it to withstand the wear to which it is subjected. Tenacity, resistance to strain. These qualities, together with malleability and ductility, are possessed by gold to such an extent that it not only resists strain when employed to restore lost con- tour, but it is possible to use it where the enamel bevel is neces- sarily long; a combination of qualities possessed by no other ma- terial used for filling teeth. Low conductivity. Gold is the best conductor of the filling materials, consequently it oftener demands a nonconducting "in- termediate." PROPERTIES OF GOLD. 87 Ease of introduction. It is generally conceded that gold is the most difficult material to manipulate, yet when its qualities are thoroughly understood, it responds readily to careful and intelligent effort. Freedom from chemical action. It is not affected by any chemical action present in the mouth. Freedom from molecular change. There is no change in the integrity of a gold filling after its proper condensation. Capability of polish. Gold is capable of receiving either a burnished or a polished surface. Good color. It is not harmonious in color with the teeth, but its peculiar yellow color forms a pleasant contrast. In addition to these qualities it possesses the property of cohesiveness. Its freedom from oxidation makes it possible to unite separate pieces of gold by pressure without the aid of heat; heat is used only for the purpose of burning off impurities and softening the gold. From the foregoing it appears that the popularity of gold as a filling material is based upon the fact that it fulfills more of the requirements for a filling material than any other substance employed. Gold for use in filling teeth must be as nearly chemically pure as it is possible to make it. The greater amount comes to us in the form of foil, or cylinders and blocks made from foil. There are several other preparations produced by reducing gold to its crystalline state, under various processes and bearing various names, as crystal, sponge, crystal mat, etc. Only foil and the vari- ous forms in which it is prepared for use will be noticed. Gold foil is prepared by beating or rolling (rolling for the heavier numbers only), and is put up and numbered in the same way as tin foil. Unlike tin, gold foil is supplied in several grades one, in which the natural cohesive quality of gold has been de- stroyed by some process; this is known as noncohesive. Another, in which this property of cohesion is destroyed only in part this is known as semicohesive. The other form is that in which the cohesive property is retained to its fullest extent; this is known as cohesive, or extra cohesive. Manufacturers mark their products as "soft," "semicohesive" and "cohesive" or "extra cohesive." The term "soft" is a misleading one. Softness is not synonymous with noncohesiveness. All of the grades may be, and are, under 88 GOLD FOIL. the best processes of manufacture, soft; this is a natural property of gold before the particles are driven into closer contact by con- densation. Gold which has been made hard by condensation may again become soft by heating to redness. This is independent of the cohesive property. Pellets, blocks, or cylinders of gold in which the cohesive quality has not been destroyed, become hard more quickly under manipulation than do those which have been made noncohesive; this is because the particles of cohesive gold stick together at all points where two surfaces come in contact, while the surfaces of noncohesive gold slip or slide upon each other. The fullest exhibition of the cohesive property depends upon the absolute cleanliness of the surfaces. Moisture, fatty matter, or gases, especially sulphuretted gases, modify or completely de- stroy cohesion. To insure the absence of any or all of these, the gold is heated to redness over a flame in which combustion is com- plete. This is called annealing; its purpose is two-fold; first, to cleanse the surfaces; second, to secure the fullest degree of soft- ness. If there is any doubt of the perfect combustion in a flame, the gold may be heated in a mica tray. The principles governing the introduction of noncohesive gold are the same as those governing the introduction of tin. Because of the hardness which is possible in a noncohesive gold filling, the range of cavities where it may be employed is much greater than for tin. As has been stated, the amount of inherent strength neces- sary to the filling in any given cavity is equivalent to the amount of strain to which the filling is subjected; this governs the amount of cohesiveness necessary in the gold for any given cavity. Those cavities where lost contour must be restored, usually require the full extent of the cohesive property. Where density of surface is required and the mass of the filling is subjected to little strain, a noncohesive filling may be faced with cohesive gold. This is ac- complished by mechanical union between the noncohesive and the cohesive i. e. a layer of cohesive foil is interdigitated with the noncohesive mass. This method is applicable to cavities of class 3, whose axial depth is great. These cavities when prepared as in Fig. 226, have retaining shape throughout their whole depth. The cohesive gold need only be employed to a depth necessary to allow of a sufficient mass of cohesive gold to be retained in the cavity, and to resist the strain brought upon it. This is illustrated in Fig. 233. NONCOHESIVE GOLD. 89 The advantages of noncohesive gold are that it is more readily adapted to the walls of the cavity, and it can be introduced in larger pieces and be perfectly condensed in a much shorter time, thus saving fatigue to both patient and operator. The same instru- ments for wedging, condensing, and finishing are employed for noncohesive gold as for tin. The instruments for cohesive gold should have fine shallow serrations and possess such points as are shown in Figs. 130 to 146. Owing to the tendency of the surfaces of cohesive gold to stick together, force should be exerted in such Fig. 233. direction, and instruments employed having such faces as will insure the perfect adaptation of each layer to the walls of the cavity. Gold foil is prepared for insertion into cavities in the same forms as tin. Where the cohesive property is retained, the indi- vidual pellets, ribbons, blocks, cylinders, or mats should be of looser structure, also flatter and smaller than for noncohesive gold or tin. Cohesive gold fillings are made by uniting the separate pieces, layer upon layer, thoroughly condensing each layer before another is added. The only combination with other metals to be noticed is gold and tin. The two foils are combined in blocks or cylinders so that 90 ZINC PLASTICS. the layers of gold and tin will alternate; the tin should never pre- dominate. This combination is useful at the cervical third of large cavities of Class 3. ZINC PLASTICS. r\ ui -j e T \ Powder, calcined oxide of zinc. Oxychloride of Zinc j Liquidi deliquesced chlonde o zinc> , , . c rj- \Powder,recalcinedoxideofzinc. Oxyphosphate of Zinc j Liquid> de ii que sced glacial phosphoric acid. Oxyphosphate of Zinc, with gelatinized liquid for capping. ( Powder, calcined oxide and calcined sulphate, of zinc. Oxysulphate of Zinc -j Liquid, gum arabic and sulphite of lime dissolved in ( distilled water. Dickinson's Capping J Powder, oxide of zinc and iodoform. } Liquid, beechwood creasote and eugenol. As none of these preparations can be considered as permanent filling materials, their response to the requirements of a filling material will be summed up as follows. They have sufficient den- sity and hardness, have low conductivity, are easy to introduce, do not change in bulk integrity, and have good color. They lack in tenacity, resistance to strain or wear, receive only an indifferent polish and are soluble in the fluids of the mouth. Oxychloride. As this preparation has been proved to be so temporary in its nature, it is used only where its peculiar power to prevent decomposition of devitalized tissue is desirable; as for fill- ing root canals in which the pulps were putrescent, or as a lining or temporary filling, where its ability to obtund sensitive dentine by destroying the terminals of the fibrillae, make it advantageous. Its combination is a chemical union, and it should be thoroughly mixed upon a glass slab, to the consistency of cream for canal fill- ings, and to a putty like mass for linings and temporary fillings. As it is white in color it is useful as a lining in teeth which have been bleached, or in large cavities where the gold or other filling material will show through the enamel if some lining material is not employed. Oxyphosphate of zinc is harder, better resists wear, and is less irritant to vital tissues. It is, however, soluble in certain fluids of the mouth, notably in the mucous secretions. Its union is a chemical one, but it does not unite so readily as Oxychloride; the powder should be added to the liquid in small amounts, thor- OXYPHOSPHA TE OF ZINC. 91 oughly spatulating or kneading the mass, with force. It should be mixed to a putty-like mass, unless it is to be introduced without pressure, as when it is used as an "intermediate " over a pulp cap- ping, when it must be of the consistency of cream. There are many preparations of varying excellence; the best results seem to be obtained from those in which the powder is finely pulverized, is heavy, and breaks apart, falling in masses, as the bottle is revolved, and those in which the liquid is thick and syrupy in appearance and sticky in feeling. Samples possessing these characteristics, and which mix unwillingly but make a fine smooth mass, so sticky that it is removed from the slab and spatula with difficulty, and losing this stickiness if rolled a little in the fingers, rebounding with a metal- lic ring when a pellet of it is dropped upon any hard surface, and breaking with difficulty after fifteen minutes, showing a clean frac- ture, generally wear well if they are carefully introduced and fin- ished, and the moisture is excluded until the mass is hard. Oxyphosphate with gelatinized fluid, oxysulphate of zinc and Dickinson's material, are not filling materials, but are intended as nonirritant, antiseptic pulp protectors or cappings. They are use- ful in all cases of exposure or where a thin layer of semidecalcified dentine remains over the pulp. They are used in conjunction with asbestos paper or a metal cap. GUTTA-PERCHA. This product of the gutta perch tree is too tough and unyield- ing in its natural state, to be utilized as a filling material. For dental use, oxide of zinc or some earthy matter is incorporated with it. It comes to us in two forms, pink, which is used for base plates, and white, the white in several grades. It has sufficient density, tenacity and strength for ordinary purposes but not suf- ficient to resist the strain and wear of mastication. It is an abso- lute nonconductor. It is easy to introduce. While it is free from chemical action, it becomes soaked and rotten after long exposure to the oral fluids. Being introduced warm, it shrinks in cooling. Although incapable of polish, the so called white varieties harmo- nize well with tooth color. Its characteristics make it one of the best "intermediates," as well as one of the best canal filling ma- terials, where too much bulk is not required, but precludes its use as a permanent filling, except in cavities upon buccal surfaces of molars and bicuspids. It is also very useful in deciduous teeth. 92 GUTTA-PERCHA. The white gutta-perchas are prepared in three grades, " low heat,' 1 "medium," and "high heat." The degree of heat necessary to soften it depends upon the amount of oxide or other substance which it contains. The several grades soften as follows: "Low heat" softens at from 140. to 200. F. Pink, base plate " " 150. " 180.F. "Medium" " " 200. " 210. F. "High heat" " " " 216. " 230. F.* All those which soften below the boiling point should be soft- ened over boiling water; the " high " grade must be softened on a glass or porcelain slab over a flame. None of the preparations should be softened in direct contact with the flame, because of the danger of burning. Warm instruments should be used in its manipulation. The " medium " preparations seem to give the best results. The pink base plate makes the best points for canal filling. The chloro- percha which is used in pulp capping and canal filling is prepared by dissolving small shavings of pink base plate in chloroform. It has been suggested that iodoform or some antiseptic be added to the solution, but as any such substance would be so firmly fixed against solution, its efficacy seems doubtful. PRACTICAL EXERCISES. Before students begin their practical exercises the teacher should demonstrate each operation. The cavities, which were pre- pared in the large clay models with enlarged copies in brass of the instruments which the students used in cavity preparation, may now be filled; use enlarged pluggers of brass, with colored cotton rolls to represent cylinders of tin or gold, and ropes and ribbons of sheet wadding (cotton) to represent ropes and ribbons of tin or gold,f soft clay of another color, or putty may be used to demonstrate the use of plastics, A little ingenuity will enable the teacher to vary the exercises to hold the interest of the students and to prevent the work becom- ing irksome The author is now able to present an illustration of a "rubber tooth form for' use in operative technics," Fig. 234, which will take *Flagg flhis was suggested by Dr. D. M. Cattell PRACTICAL EXERCISES. 93 the place of the toothbrush handle; the bottom of the base is slight- ly convex in order that the cavities shown in Fig. 187 may be made in it. The teeth are typical forms thus giving opportunity for the formation of typical cavities. The material is much easier to cut than dentine or bone, but dense enough to give good margins. Another advantage is that the character of the material demands sharp, keen edged instruments. The teeth are placed far enough apart to permit of easy access to all surfaces, consequently the stu- dent will gain practice in contour iorform only. Practice in con- tour for contact and the preservation of the interproximate space must be gained by filling cavities (with plastics) in teeth in the dummy articulator. Fig. 234. The three points of contour, contact, and occlusion should be carefully studied, taking as a basis a thorough recitation and drill of pages 130 to 153 of Black's Dental Anatomy, supplemented by the arrangement of the teeth in the dummy articulator, and by the study of models. Exercise 1. Gutta-percha. The teacher selects several cavities in the teeth in the dummy articulator which the student fills with gutta-percha, pink base plate. One cavity is filled with a pellet of sufficient size to fill the cavity, which is softened over boiling water or on a Flagg's gutta-percha warmer. It is then inserted in the cavity with warm instruments, the surplus is removed and the sur- 94 PRACTICAL EXERCISES. face finished with warm burnishers. Another cavity is filled with smaller pellets, softened as before, using cold instruments, trim- ming off the surplus with sharp trimmers after the mass has hard- ened. The surface may then be finished with a pad of cotton or spunk wet with chloroform. It is presumed that the student has already had some expe- rience in handling gutta-percha in his pulp protection, and canal filling exercises; but the teacher should require such further exer- cises as will thoroughly familiarize the student with the different grades of this valuable material. Exercise 2. Oxychloride of zinc. After some preliminary ex- ercise in mixing this cement, the student is required to insert some in large cavities as a cavity lining; to insert one filling, keeping it dry until the mass is perfectly set or hard, also one which he may bring in contact with saliva before it is thoroughly set; this is done that he may note the different results. Finish with lancet trim- mers and sandpaper strips. Exercise 3. Oxyphosphate of zinc. The preliminary exer- cise should be thorough instruction and practice in mixing this cement, making tests of the various mixes Several varieties should be presented. Then a number of the partially prepared cavities in teeth in the dummy articulator should be filled to restore contour and contact. Fillings in cavities involving the proximate surfaces of bicuspids and molars should be inserted with the aid of Dunn's hand matrix. Some of the fillings should be protected from moisture until perfectly hard, others should be brought in contact with saliva while they are hardening, the stu- dent taking careful notes of the results in each case. Finish the same as oxychloride. Students should be allowed all the oppor- tunity possible to become familiar with the peculiarities and pos- sibilities of this material. If possible, the teacher with the assist- ance of the class should make a batch of oxyphosphate. Exercise 4. Amalgam. Students will be much benefited if they are allowed to assist in the manufacture of an amalgam alloy and of copper amalgam. Whether this is practicable or not, they should mix amalgam, both soft and dry, and test the mixes by inserting them in glass tubes which are subsequently immersed in aniline dye. One cavity should be filled with a soft mix and one with a dry mix, which should be allowed to harden before the fill- ing is finished. One cavity should be filled with a soft mix and PRAC7ICAL EXERCISES. 95 one with a dry mix which should be wafered and finished at once. Wafering is the expression of all surplus mercury before the mass is inserted in the cavity. Careful notes should be taken of the results under the different manipulation. The partially prepared cavities in the teeth of the dummy will give ample practice in the inserting, contouring, and finishing of amalgam. ^All amalgam fill- ings must be carefully finished after they are thoroughly hard, with finishing strips and discs of increasing fineness. / Exercise 5. Making ropes of tin foil. Cut a leaf of No. 4 tin foil into three strips; roll each strip in a clean folded napkin; then grasping the ends with the thumb and index finger of each hand, twist into a rope, tight or loose as is desired. This preparation is applicable for gold also, except that for cohesive foil the roll should not be twisted. Cohesive gold should never be touched by the fingers. Exercise 6. Making ribbons of tin foil. Cut the leaves of No. 4 foil as for ropes; with a paper folder fold each strip lengthwise to the desired width. This is the best form of preparation for cohesive gold foil. Exercise 7. Making cylinders of tin foil. Prepare ribbons of the width desired for the length of the cylinders. Roll each ribbon on a small, square, smooth broach, holding it tight between the thumb and finger; the size of the cylinders is governed by the length of the ribbon. This form of cylinder is applicable only for tin and noncohesive gold. Exercise 8. Tin fillings of ropes or ribbons. In cavity C, Fig. 187, insert a rope of tin as shown in Fig. 282, beginning at one end, pressing or crowding each fold against those which have pre- ceded it. In folding the ropes or ribbons, be sure to leave suffi- cient amount protruding from the cavity to permit of condensing and finishing. When enough has been introduced into one end to insure the wedging of the mass, fill the other end in the same man- ner. As the two masses approach each other, that portion next the walls of the cavity should be in advance of the rest; in this way a small opening will be left in the center of the filling. After the mass has been thoroughly condensed laterally by the use of wedge-shaped instruments in this central opening it may be filled with smaller ropes. Instruments used in this exercise should be shaped as in Figs. 121, 122, 123 and 124. After the cavity is wedged full the surface should be thoroughly condensed with foot 96 PRACTICAL EXERCISES. instruments having convex faces, as in Figs. 135 and 136. This exercise should be by hand pressure only. The surplus may be trimmed off with files and the surface finished with sandpaper or emery paper strips of increasing fineness, using chalk or whiting and rouge on a chamois skin strip, to polish; or the surplus may be trimmed off with sharp lancet trimmers and the surface burnished. Exercise 9. Tin fillings of cylinders. In cavity d, Fig. 187, place a row of large cylinders around the circumference of the cavity, next the wall, as shown in Fig. 231, flattening them against the wall. Continue placing cylinders in concentric layers, crowd- ing each row against those which have preceded, until only a small opening is left in the center. This opening may be filled with a conical cylinder, or with a rope, as in Exercise 8. After the cavity is full the surface must be condensed as in Exercise 8. The same instruments are used as before. The remaining cavities, a, b and e, may be filled, using ropes, ribbons, or cylinders of heavier foil, as the teacher may direct. One or more cavities may be filled with shavings of tin, prepared as described on page 83. A com- pound or double dovetailed cavity resembling Fig. 226, should be prepared in either end of the toothbrush handle or in the base of the rubber tooth form, which involves the surface and the end. One of these cavities should be filled with ropes of tin foil, the other with tin and gold ropes or cylinders for the basal two-thirds of the cavity, filling the remaining third with gold. As noncohesive gold works very much as tin does, tin instead of noncohesive gold may be used to give the students practice, but one small filling of noncohesive gold should be inserted to impress the student with the points of difference. Exercise 10. Tin and gold. Ropes or ribbons of tin and gold are prepared by placing a strip of tin foil upon a strip of non- cohesive gold foil, rolling or folding it with the tin inside of the gold. Cylinders of tin and gold ribbons may be made in the same manner as cylinders of gold or tin alone. These preparations are inserted in the same manner as described for tin in cavities which the teacher shall select. Exercise 11. A cavity of division A, class 2, Fig. 216 should be filled with cohesive gold, beginning with semicohesive gold and finishing with extra cohesive gold. The gold for this exercise should be short pieces cut from ribbons made of leaves of No. 4 foil cut into four strips. (jA.ll gold fillings should be finished with PRACTICAL EXERCISES. <7 fine files or file trimmers, and polished with fine emery stripaand rouged chamois skin strips. In these exercises all cavities should be inspected and their form and margins passed upon by the teacher before the student is allowed to fill them. Each filling should also be inspected and passed upon before the student is allowed to proceed with the next exercise. SPECIMEN COURSE AS USED BY THE AUTHOR. T t R \f J Black's Dental Anatomy. '" j Weeks' Manual of Operative Technics. DENTAL ANATOMY. f Terminology and Nomenclature. 1. Descriptive Anatomy I Notation. of the Teeth. j Form. [ Arrangement. 1 Component parts, their Macroscopic < form, proportion and 2. Structural Anatomy J ( relation to the whole. of the Teeth I Study by recitation and practical exercises. PRACTICAL EXERCISES. DESCRIPTIVE ANATOMY. IN THE DRAWING BOOKS. Make outline drawings of the principal surfaces of the teeth. Model in clay one tooth of each class. Select a tooth of each denomination from a miscellaneous lot and arrange them upon wax for future use. STRUCTURAL ANATOMY MACROSCOPIC, LONGITUDINAL SECTIONS. Select and mount upon blocks, teeth of one side of each maxilla. File the teeth thus mounted until pulp chambers and canals are exposed, broaching canals with piano wire explorer as the filing progresses. Make prints in the printing book of every aspect of six teeth of each denomination, superior and inferior. 1-2-8 In longitudinal sections of ^-^ only la. and m. aspects need l"*w*O be shown, but in ' ' b. li. m. and d. aspects should be shown. 4-O-D-7-O 98 PRACTICAL EXERCISES TRANSVERSE SECTIONS. Cut sections of teeth of one side, upper ana lower, as in Figs. 9 and 10 Manual of Technics, showing form at gingival line, mid- root, and apical third. Print on the pages ruled for the purpose, as in Fig. 7, Manual of Technics. Exchange sections and print in this way six pages. Duplicate sheets of each leaf must be furnished the teacher. MICROSCOPIC. Cut and mount one longitudinal and one transverse section of an incisor. Make drawing in drawing book of the several tissues as shown under the microscope. The student needs for these exercises : 1 stick Am. Ex. sealing wax. 1 half round file, 8 inch, bastard cut, medium coarse. 1 bench vise. 1 alcohol lamp. 1 jewelers' hack saw with 12 saw blades. 1 wax spatula. 1 excelsior ink pad. 1 rubber pad, 3 in. x 6 in. x % in. 1 book for printing, open at end. Leaves ruled as in Figs. 6 and 7, Manual of Technics. 1 drawing book. Some fine canal explorers. Some fine sandpaper, and 00. 1 toothbrush. 1 yard cotton cloth. 1 salt mouth bottle with cork. 1 large ointment jar. To insure uniformity, and to give students advantage of lowest prices, these materials are to be had at the desk. The teacher provides the teeth for cutting, and the blocks for mounting ; also paper tablets same texture, size and ruling as books, and some tablets of similar paper for experimental print- ing, and clay for modeling. OPERATIVE TECHNICS. T T t urn t -f Classification according to form and uses. | Action or use for each form. PRACTICAL EXERCISES. 99 / Gaining entrance to canal. IT Canal J Removal of P ul P- ~\ Cleansing and preparing canals. ( Filling canals. J.,, P . . ( Classification from location and causes. | Preparation on principles governing. [Conservative. \ Treatment and protection, / Capping. IV. Pulp Treatment. <^ Radical i Surgical devitalization. t I Devitalization by drugs. f Characteristics and composition. V. Filling Materials. ] ^S'.Too into cavi.ia, ' Finishing fillings. Study by recitation from Manual of Technics, with practical exercises. PRACTICAL EXERCISES. Arrange in dummy articulator the teeth selected from miscel- laneous lot. Apply rubber dam in the several ways. Wrap broaches. Gain entrance to canals in one incisor, one bicuspid and two molars, removing pulp from same. Cleanse and prepare canal for filling. Fill the canals thus prepared. Prepare cavities as in Fig. 187, Manual of Technics, in tooth- brush handle or celluloid teeth. Prepare cavities of each division of the several classes, in teeth in the articulator. Treat and cap two or more exposed pulps. Fill the cavities in toothbrush handle with tin. Fill the other cavities prepared : Two or more with gutta-percha. " " " zinc phosphate. " " " amalgam. " " " gold. All remaining cavities are given proper marginal outlines and the contour of the teeth restored with" oxyphosphate or gutta- percha. Instruments for this work as per list. Filling materials and medicaments furnished at the desk. Recitations every session. 100 PRACTICAL EXERCISES. Written quizzes are given upon completing each division of a topic and marked. Marks are given on the cutting of sections, silhouette printing, drawings and operations. These markings, averaged with those of the final examination, determine the standing of the student. The examination in dental anatomy is given when the. work is completed. That in operative technics at the close of the*term. In the last half of the second semester, those students who have an average of 80 per cent, or above, in their practical work, are permitted to enter the infirmary, to put in practice under the direction of the clinical professor, the principles which have been acquired in the technic laboratory. No student will be permitted to begin practical work unless provided with the instruments and other necessaries required by the college. GLOSSARY. Abrade. To rub or wear away. Abrasion. The act of wearing or rubbing off by friction or attrition. Absorb. To drink in; imbibe, as a sponge. Absorbent. Capable of imbibing, taking up moisture. Adhere. To stick fast, one thing to another. Adhesion. The act of adhering; uniting as by cement. Adhesive. Sticky; tenacious. Affinity. Inherent likeness between things. In chemistry, that force by which the atoms of dissimilar bodies unite in certain definite proportions to form a new compound. Alveolar, Alveolus. A deep cavity or socket. Alveolar processes. The processes of the maxillary bones containing the sockets of the teeth. Alloy. An artificial compound of two or more metals com- bined while in a state of fusion; result, a new metal. Amalgam. A compound of mercury with, another metal, or an alloy in which the combination is by the action of the mercury. Amalgamated. Mixed or united with mercury. Amorphous. Without form; having no regular structure. Anaesthesia. Insensibility, especially to pain. General, as applied to the whole body; local, as applied to a part. Anastomose. To communicate or unite; inosculate, or run into one another. Angle. The difference in direction of two intersecting lines. The figure or projection formed by the meeting of two lines; a corner. Anneal. To heat; to treat by heating to redness and gradual- ly cooling; to soften. . Annealed. Softened, heated. Anodyne. Having power to remove pain. A drug which relieves pain, as an opiate or narcotic. Antiseptic. Anything which destroys the microorganisms of 102 GLOSSARY. disease, putrefaction, or fermentation, or which restricts theif growth and multiplication. Apex. The tip or point of anything. The end or point of the root of a tooth. Plural, apices. Apical. Relating to the apex. Apical Foramina. The small openings in the apices of the roots of teeth, which give passage to the vessels and nerves sup- plying the pulp. Arch. In geometry, any part of the circumference of a circle. Dental arch. The curved line of the teeth in their sockets, cor- responds to the alveolar border in each jaw. Articulator. An apparatus for obtaining the correct articula- tion or occlusion of artificial teeth. The dummy articulator is an apparatus for the correct arrangment and retention of natural teeth for operations in operative technics. Asbestos. A fibrous variety of horblende, composed of sepa- rable filaments. Asbestos Paper or Felt. A nonconducting substance made from the fibers of asbestos. Aseptic. Free from the living germs of disease, fermenta- tion, or putrefaction. Asepsis. Absence of the living germs of disease, etc. Atom. The unit of matter. The smallest mass of an ele- ment that exists in a molecule. Atomic. Pertaining to an atom. Attrition. The act of wearing away by rubbing or friction. Axial Wall. The wall which is parallel with a longitudinal surface and opposed to it. In cavities, that wall which is parallel with an axial surface. This wall has formerly been variously designated as the floor or base. The author applies the term base to that portion of cavities which is at right angles with the axis; as basal wall of a proximate cavity (same as cervical wall). Axis. The central line of any symmetrical or nearly symmet- rical body. Bevel. The obliquity or inclination of a particular surface of a solid body to another surface of the same body. Bevel of blades, the angle of the cutting edge. Biscuspid. Having two cusps. The teeth in either jaw which succeed the deciduous molars. GLOSSARY. 103 Blade. The cutting part of a knife or any cutting tool or instrument. Broach. A spit; a stake or any sharp pointed thing. In den- tistry a slender, pointed instrument, either smooth or barbed, for use in root canals. Buccal. Pertaining to the cheeks, or sides of the mouth. Applied to the surfaces of the teeth which are presented toward the cheeks. Bur. A form of drill or reamer with a circular head, having a series of leaves or cutting edges around its circumference; designed for side cutting. Burnisher. An instrument of hardened steel or other hard substance, having a highly polished surface; designed for smooth- ing, polishing and condensing metallic surfaces. Calcific. That makes or is converted into a salt of lime. Calcification. The deposition of lime salts in a tissue. Calcined. Treated by heat for the purpose of driving off im- purities or reducing the substance to a friable mass. Calculus. A general term for inorganic concretions or deposits. In dentistry that substance deposited upon the teeth from the saliva or serum. Canal. A duct, channel. The channel in the center of the roots of teeth, which contains the elongated portion of the pulp. Capping. The operation for the covering and protection of an exposed pulp from irritation and thermal changes. Cavity. A hollow. That portion of a tooth destroyed by caries. Cement. A composition which being made in a plastic con- dition becomes hard. The term applied to the several compounds of zinc used in filling teeth. Cement substance. The intervening substance which unites the enamel rods. Cementum. The cortical substance resembling bone which covers the roots of teeth. Cervical. Pertaining to the neck. Applied to the constricted part of a tooth where the enamel joins the cementum. Chisel. A tool consisting of a handle, shank and blade; de- signed for heavy cutting. Clamps. Instruments for holding things in position or for holding two or more things together by pressure. 104 GLOSSARY. Cleavage. The act of splitting. That property of enamel which permits it to break readily in one direction. Coalescence. The act of uniting. Organic union of s'.nllar parts. Cohesive. Having the property of sticking together. Cohesion. The force by which the molecules of the same material are held or bound together. Columnar. Having a generally cylindrical form, with gi eater length than thickness. Compatibility. The quality of being harmonious, not antag- onistic or injurious. Component.. Composing; entering into the composition of anything. Concave. Hollow. Any part of the circumference of a circle when viewed from the center. Concentric. An arrangement, of parallel circles around a com- mon center. Condensation. The act of being made compact; consoli- dation. Conducting. Conveying; carrying; transmitting, as heat or electricity. Conservative. Power or tendency to preserve from injury or loss. Conservative treatment of the pulp is that which attempts to save its life or vitality. Consistency. Physical constitution; as dense, soft, etc., as consistency of cream, mortar, etc. Contact. A touching of two bodies. Contour. The outline of a figure or body; contour filling, one which restores or makes form. Convex. Rounded; arched. Any portion of a circle as viewed from the outside. Corrosion. The act or process of eating or gnawing away; the disintegration of a-surface, especially by chemical agents. Corrosive. Any agent which will corrode, as an acid. Decalcified. Deprived of lime. As the lime salts are dis- solved out in the process of decay the dentine becomes decalci- fied. Deciduous. Living or existing during a definite period; not permanent, or perennial. GLOSSARY. 105 Decomposition. The act or process of separating the con- stituent elements of a compound substance; the process of reduc- ing an organic body to a state of decay or putrefaction. Deliquesced. Melted or dissolved. To become liquid by absorbing moisture from the air. Dentine. The principal substance composing teeth. It is made up of very fine close set tubules or canaliculi, whose general direction is at right angles with the pulp chamber. Denuded. Stripped or divested of covering; laid bare. Desiccated. Thoroughly dried, deprived of all moisture. Devitalized. Deprived of life, or the qualities which sustain life. Disk. A flat or approximately flat circular plate of metal or other substance. Distal. Away from or opposite the median line. Applied to the surfaces of the teeth which are farthest from the median line following the dental arch. Same as posterior. Disto-lingual. The term applied to the angle formed by the junction of the distal and the lingual surface. Disto-marginal. The term applied to the angle formed by the junction of a distal surface and a margin. Dowel-pin. A pin or tenon used for securing together two pieces of anything, as a crown to a root. Dovetailed. Having the form of a pigeon's tail spread. Drill. An instrument for boring holes. Specifically an instru- ment which cuts only at the end. Ductility. That property of metals which renders them capable of being extended by drawing; as gold into wire. Edge-strength. That property which renders an extended edge capable of resisting strain. Electrolysis. The decomposition of a chemical compound into its constituent parts by electricity. Elementary. Primary; simple; uncompounded. Embryological. Relating to the subject of embryos. Enamel. The hardest part of a tooth; it is composed of six- sided prisms or columns and covers the crowns of teeth. Environment. The aggregate of surrounding things or con- ditions. Escharotic. Caustic; having the power of searing or destroy- ing the flesh. 106 GLOSSARY. Excavators. Instruments for scooping out decay, enlarging and shaping cavities. Excision. The act of cutting off, out or away. Explorers. Instruments for searching out cavities on the sur- faces of the teeth; or for examining and following cavities, sinuses and root canals. Extractors. Instruments for removing or withdrawing pulp tissue from canals. Faces. The principal surface of anything, the side or part of an instrument upon which its use depends. Fibrillae. The delicate threadlike processes of the outer layer of pulp cells, which penetrate the dentine. Fissure. A cleft ; a crack. Fissures in teeth arise from structural imperfections in the enamel. Foramina. The openings in the apical .portion of the roots of teeth which give passage to the vessels supplying the pulp. Force. Active power ; power in motion. Formative. Having the power to give form or shape. Per- taining to development. Fracture. Separation of the parts of a solid body by the ac- tion of force. Fusing. Melting ; reducing from a solid to a fluid state by heat. Galvanic. Pertaining to galvanism ; current electricity pro- duced by a chemical battery. Germicide. A substance capable of killing germs or micro- organisms. Gingival line. The line of attachment of the gums, gingivae ; the line of junction between enamel and the cementum. Gingival Margin. The free margin of the gums; the mar- gin of a crown surface which borders on the gingival line. Grade. Relative position or standing as regards quantity, quality, or office. Groove. A long shaped depression or hollow. Gums. The soft tissue which covers the alveolar parts of both upper and lower jaws, enveloping the necks of the teeth. Gutta-Percha. The concrete juice of the Isonandra gutta- percha tree. Handle. That part of an instrument to be grasped by the hand in using it. GLOSSARY. 101 Histology. The science of minute or microscopical anatom- ical structure. Homogeneity. Of uniform structure. Homogenous. Of the same kind; uniform. Hyperaemia. Excessive accumulation of blood in any part. Incisal. That which cuts or divides. Incisors. Incisive or cutting teeth. The two teeth on each side of the median line in both upper and lower jaws. Inferior. Situated below or in an inferior position. Inflammation. A morbid condition characterized by heat, pain, redness and swelling, generally the result of irritation of some kind. Ingot. A mass of metal cast in a mold. Inlays. That which is laid into or inserted in a surface. Integrity. Unimpaired condition; soundness of state. Interdental. Occurring between the teeth. Interdigitation. State of being interwoven or run into each other. Intermediate. Intervening; interposing; coming between. Irritation. The act of evoking some action or change of state. Labial. Pertaining to the lips. Applied to the surfaces of the teeth presented to the lips. Lancet. A small surgical instrument for cutting soft tissues, as opening abscesses, etc. Ligatures. That which serves for tying, binding or uniting. Lingual. The term applied to the surfaces of the teeth next to the tongue, both upper and lower. Longitudinally. In the direction of length. Lymphatic. Pertaining to the vessels which convey lymph. Macroscopic. That which is seen by unaided vision. Malleable. Capable of extension by hammering or rolling. Mallet. A hammer like instrument for driving another tool or instrument. Manipulation. Management or use of anything by the hand. Margin. Border; as incisal border or margin of labial sur- face; gingival border or margin of the gums. Mastication. Act of chewing. The process of triturating the food with the teeth. Matrices. Plural of matrix. 108 GLOSSARY. f Matrix. A mold which gives form to material forced into it. Matrix Clamp. An instrument for holding a matrix in po- sition. Membrana Eboris. Term applied to the outer layer of cells of the pulp. Mesial. Being in the middle. Pertaining to the middle line. The surface presented toward the median line. Mesio-marginal. Term applied to the angle formed by the junction of a mesial surface and a margin. Metallurgy. Science of metals. - The art of working metals. Microscopic. That which cannot be seen without the aid of a microscope. Molar.. Belonging to a mill. Term applied to the grinding teeth. Molecular. Relating to molecules. Molecule. The smallest mass of any substance capable of existing in a separate form. Mortise. A hollow or recess cut in any material to receive a tenon or inlay. Mucus. A viscid fluid secreted by the mucous membrane. MUCOUS Membrane. The membrane which lines all cavities and canals in the body which communicate with the air. Necrosis. The death of a circumsrcibed piece of tissue. Nodules. A small mass of mineral matter having a rounded form. Nomenclature. A list of scientific names arranged system- atically. Nonconducting. Incapable of transmitting any force, such as heat, or electricity. Noncorrosive. Incapable of being acted upon by corrosive agents. Oblong. Elongated. Having greater length than breadth. Obtund. To dull, blunt, or deaden. To reduce the violent action of. Obtundent An agent which obtunds. Occlude. To shut or close together. Occlusal. A term applied to the cutting edges or grinding surfaces of the teeth; those surfaces which occlude. Octahedron. A solid bounded by eight faces. Odontoblastic. Pertaining to the odontoblasts. GLOSSARY 109 OdontoblastS. The cells from which dentine is developed. Opaque. Impervious to light. Not transparent. Oral. Of or pertaining to the mouth. Oval. Having shape of a longitudinal section of an egg; elliptical. Oxidation. The act of combining with oxygen. Paraffine. A substance obtained by the dry distillation of wood, peat, bituminous coal, wax, etc. Is tasteless, inodorous and resists the action of acids and alkalies. Pathology. The science of diseased conditions. Pericemental The term applied to the membrane investing the root. Periphery. The outside or superficial part of a body. Photo-micrographs. Enlarged or microscopic photographs of microscopic objects. Pit. A hollow or small depression. A round imperfection in the surface of the enamel. Plastic. Capable of being moulded into new forms. Plasticity. Capability of being moulded. Pliers. Small pincers with long jaws capable of handling small objects. Pluggers. Instruments for driving or packing filling material into cavities. "Potential cauterants." Possible, as opposed to actual cauterants. Precipitation. The process by which any substance is made to separate from others in solution, and fall to the bottom. Prophylactic. Preventive, defending from disease. Protoplasm. A nitrogenous substance from which nuclei are formed. Proximate. Next ; immediate ; without the intervention of a third. Pulp. The formative organ of the tooth consisting of connec- tive tissue, nerves, and blood vessels. Pulp Chamber. The chamber in the crown of a tooth which contains the bulbous portion of the pulp. Pus. The cream like fluid found on the surfaces of abscesses or sores. Matter. Putrescent pulp. A pulp which has become disorganized ; decomposed. 110 GLOSSARY. Radical. Pertaining to the root. Thorough. Applied in dentistry to mean the extirpation and removal of the pulp. Reamer. An instrument for enlarging holes. A side-cutting instrument. Regular system. Isometric, or having three equal axes at right angles with each other. Rhombic. A solid bounded by six equal and similar rhombic planes. Diamond shaped. Rhombic System. Crystallizing into rhombic form. Ridge. A prominent border. An elevated line or crest on the surface of a tooth. Root. That part which is fixed in the alveolar socket, and supports the tooth. Rubber dam. A thin sheet of flexible soft rubber. Sealer. An instrument used for removing deposits from the teeth. Semicohesive. Having cohesive property partially de- stroyed. Semidecalcified. Partly decalcified. Sensitive. Having sense or feeling. Capability of receiving imp'ressions from external objects. Applied to a tooth means in- crease or perversion of normal sensitiveness. Separators. An instrument for forcing teeth apart to gain space between them. Septic. Applied to condition resulting from decomposition putrefaction, or fermentation. Serrations. Notches which give points or teeth, like the notches of a saw. Socket. An opening or cavity in which anything is fitted. Solution. Preparation made by dissolving a solid in a liquid. Spatula. An instrument having flat blade with unsharpened edges. Spherical. Having the form of a globe or ball. Spheroidal. In crystallization, globose; bounded by convex faces. Stability. State of resisting change. Permanency. Contin- uing in same state or condition. Sterilized. To render free from living germs. Stratum granulosum. Applied by some authorities to the dividing line between the enamel and the dentine. GLOSSARY 111 Sulcus, pi. Sulci. A more or less linear and shallow depres- sion. Syringe. An instrument capable of drawing in fluid and ejecting it forcibly. Tarnish. To diminish or destroy the luster of. A slight change in surface occasioned by contact with air or liquid. Technic. That which relates to the practical part. The per- formance, the manipulation. Tenacity. Toughness. Having great cohesive force between its particles. Terminal. The end, limit. The extreme end or boundary of any organ. Therapeutics. The composition, application and mode of operation of remedies. Thermal. Pertaining to heat. Tissue. An aggregate of similar cells and cell products in a definite fabric. Tortuous. Winding. Full of twists or turns. Crooked. Traction. State of being drawn. Triturated. Rubbed or ground to a powder or pulp. Tubuli. Plural of tubulus; a tube, duct, canal. Wedge. An acute angled, triangular prism driven between objects to be separated. Ex., an ax. Welded. United or consolidated. INDEX. Absorbents, cotton, spunk and bibulous paper 39 Adjuncts 37 Alloy, characteristics of metals for 78 denned 77 Aluminum, characteristics of 80 influence in alloys 81 Amalgam, advantages and objections .81, 82 chemical and electrical changes 82 color 82 compatibility with tooth substance 82 conductivity . . . . , 82 copper 81 copper, use of 83 defined , 76 density and hardness 81 ease of introduction 81 finishing 83 inserting 83 instruments 31 introduction into cavities 83 lack of ductility and tenacity 82 mixing 83 molecular change 82 practical exercises 94 testing 94 Angle between blade and shank, purpose of . ' . . . . 20 in pluggers, purpose of 33 sealer, purpose of 23 Annealing of gold 88 Antimony, characteristics of 78, 79 influence in alloy 78, 79, 80 Application of drugs for devitalizing 73, 74 Applying rubber dam 39, 44 Arrangement of teeth 6 Arrested development in relation to decay 53 Arsenious acid for devitalizing pulp. 73, 74 Asbestos for pulp capping and protection 69, 70 Automatic mallets 37 Auxiliary dovetail 62, 63 Barb broaches 35 Black, G. V., course, foundation for all operative technic courses 2 114 INDEX. Black's one-two-three 50 pioneer course in operative technics 2 proposed course 2 Blade, defined 17 angle between blade and shank .... 20 bevel 17 finding angle 'of 17 Blocks, fastening teeth on 10 marking of 9 Broaches, barbed 35 smooth 35 Swiss 35 use of 50 wrapping with cotton 50 Burnishers 35 Burs, action of 2(> finishing 26 Canal, cleansing 49, 50 cleansing, instruments for 50, 51 drying 48, 50, 51 enlarging opening to, with burs 47 explorers ' 35 exploring while cutting sections 10 fillingof 48, 51 gaining entrance to 44 instruments 35 instruments for removal of pulp 47, 48 paraffine for filling 52 point of opening . 44 removal of putrescent contents 49 reaming of 47, 50, 51 rendering aseptic 50 rendering contents inert 49 requisites for filling material 48 shape of opening 44, 45 treatment, syllabus 43 with putrescent pulp 49 Capping pulp 09 materials for 69, 70 ' practical exercises 70 Carbolic acid for devitalizing pulp 73 Carborundum disks and points 29 Cattell, D. M., outline of course 3 Cavities, class 1, division A, rules for outline 58 class 1, division A ,. 56 class 1, division B 59 classification, diagrammatic 53, 54 classification and preparation of 53 INDEX. 115 > Cavities, classification, reasons for 53 class 1, rules for outline , 59 class 2 59 class 3 62, 63 explorers ,. 35 fillings as inlays 54 filling of, general consideration 75, 76 formation of, for tin 85 in which tin may be employed 85 outline 61 outline, class 2 59 pit and fissure 56, 58 predisposing cause 53 preparation of, class 3 63 preparation of, practical exercises 63, 06 preparation of, for gold 63, 66 preparation of, for plastics 63, 66 preparation of , for tin 64, 66 Cavity form, rules for, class 1 and 2 59 Cement, instruments for 31 Chemical and electrical changes in amalgam 82 Chisels, manner of holding 46 relation of blade to handle 20 shaping 16, 20 Chloro-percha 92 for canals 49, 52 for pulp protection and capping .69 V 70 Chloride of zinc for devitalizing pulp 73 Clamp, matrix 85 rubber dam 35 Classification of cavities, diagrammatic 53, 54 and preparation of cavities , 53 and preparation of cavities, reasons for 53 Cloth strips for finishing 29 Cohesion of gold 87, 88 Cohesive gold 87, 88 Color of amalgam 82 Compatibility of amalgam with tooth substance 82 Condensing instruments. A 31 Conductivity of amalgam 82 of tin 84 Conservative pulp treatment 67, 69 Contour for contact 93 for form 33 Copper amalgam , 31 amalgam, use of 83 characteristics of . 77, 78 79 influence in alloys 78, 79 80 116 INDEX. Corundum, defined 29 disks and points 29 and hard rubber disks and points 29 Cotton absorbent , 89 Curve between blade and shank 20 in plugger, use of 33 in sealer, use of 23 Decay, predisposing cause 53 Dentine, removal of decayed 47 removal of decayed, instruments for 47 Density and hardness of amalgam 81 Dentinal pyramid 55 class 1 and 2 58, 59 Development, arrested, relating to decay 53 Devitalization of pulp, by arsenic 73, 74 by carbolic acid 73 by chloride of zinc 73 by drugs. 73 surgical 71, 72 practical exercises 74 Dickinson's material 90 Disks, Arkansas, Scotch, Hindostan 29 celluloid 29 copper and diamond dust, emery paper 29 corundum 29 cuttle fish 29 felt 29 garnet 29 paper, grades and forms of 29 sandpaper , 29 soft rubber 29 Dovetail, auxiliary 62, 63 Drawing microscopic sections of teeth 14 outline of sections 14 surface of teeth 6 Dressing pliers, noncorrosive. 41 Drills, action of , 26 for root canals 26 Drugs, devitalization of pulp by 73 Drying canals 48, 50, 51 Ductility of amalgam 82 tin 84 Dummy articulator 6 Ease of introducing amalgam 83 Electro-magnetic mallets 37 Electrolysis, removal of pulp by 73 Enamel, bevel for protection of 55, 56 form and thickness of 8, It * INDEX. 117 Enamel in relation to mortise , . 55 pyramid 55 pyramid, class 1 and 2 59 Enlarging canal 47 Excavators, convex edge, purpose cf 23 curved 23 hatchet 23 hoe 23 primary form 23 rights and lefts for lateral cutting 23 shaping 16 single instrument 23 spoon or scoop 23 square pointed, purpose of 23 Excluding moisture, how accomplished 39 Explorers, canal 35 cavity 35 Files, finishing 26 flexo 26 flexo finishing 26 flexo for saw frames 29 handles of '26 separating 26 trimmers 26 Filling canals ; 48, 5i cavities, general consideration 75, 76 material, general consideration 76 material for canals 48 material, requisites for 76 material solidity, how attained 31 material gold 86, 87, 88 Filling teeth, practical exercises 92 with ropes or ribbons of tin 86 with tin cylinders 85 Fillings in clay models 92 Finishing amalgam 83, 95 gold 97 gutta-percha 94 oxychloride of zinc 94 oxyphosphate of zinc , 94 tin 96 Foil carriers 39 gold 89 gold, preparation for inroduction 89 tin 84 Force, laws of delivery 32 Form, study of 6 Function of pulp 67, 68 118 INDEX. Gaining space 37 Gold, advantages of as a filling material 87, 88, 89 annealing of 88 and tin 89 as a filling material 86, 87 characteristics of 87, 88, 89 cohesion of 88 cohesive, how introduced 31, 89 cohesive, instruments for ... .31, 89 cohesive, instruments for introducing 31, 89 finishing 97 foil 89 preparation of, for insertion 89 influence in alloys 78, 79, 80 insertion of . 88 noncohesive 88, 89 noncohesive, advantages of 89 noncohesive, how introduced 31 , 89 noncohesive, instruments for 31, 88, 89 noncohesive, introduction of 88 noncohesive, practical exercises 9o, 96 preparation of 87 semicohesive 87 soft 87 Grinding instruments 28 Gutta-percha instruments 31 characteristics of 91 finishing 94 for canals 47, 50 for pulp protection and capping 69, 70 high heat 92 insertion 92 low heat 93 manipulation of .... 92 medium 92 pink base plate 92 practical exercises 92 Hand mallets 37 Handle for file 26 for instruments 20 for lancet 23 socket 20 Inlays fillings 54 mortise for 54 Insertion of amalgam 83 gold 88 gutta-percha 92 oxychloride of zinc 94 INDEX. 119 Insertion of oxyphosphate of zinc 94 tin 95 Instruments, amalgam 31 blades of 17 canal 35 classification of 18 description of 17 enamel, bevel of blade 20 enlarged 92 for filling 31 for finishing fillings 26 for gutta-percha 31 for introducing tin 85 for removal of pulp 47, 51 for tin and noncohesive gold 31 for tin 95 for working plastics 31 grinding 29 hardening 17 noncorrosive 31 polishing ; 16 sharpening 17 tempering 17 Introductory 1 Knowledge, two kinds 1 Lancets, description of 23 Lancet trimmers . 29 Ligatures 39 Making cylinders 95 ropes or ribbons 95 Mallets, automatic .' 37 electro magnetic 37 hand 37 mechanical 37 pneumatic 37 Manual training, underlying principles 1 Materials for filling cavity, general consideration 75 requisites for 76 tin 84 Material for wedging 39 Matrices, application of 37 purpose of 37 Matrix clamps 35 Mechanical mallets 37 separators 37 Mercury, characteristics of 77, 78 influence upon metals 77, 78, 79 Metal disks in pulp capping 71 120 INDEX. Metals for amalgam alloys , 77 Mirrors, mouth 39 Mixing amalgam , 88 oxychloride of zinc 94 oxyphosphate of zinc 94 Modelling teeth 6 Molecular change, freedom from in tin 85 in amalgam 82 Mortise, dovetailed 54 grooved 54 plane 54 rounded 54 various forms 54 Mouth mirrors 39 Nomenclature = 5 Noncohesive gold 88 advantages of 89 instruments for introducing , 89 introduction of 88 Opening of cavity, instruments for 46 Operative technics, governing principles 1 Outline of course 5 Oxychloride of zinc 90 finishing of 94 for canals 49 for pulp protection and capping 69, 70 insertion of 94 mixing of ," 94 practical exercises 94 Oxyphosphate of zinc 90 finishing of 94 for canals 49 for pulp protection and capping 69, 70 insertion of 94 mixing of 94 practical exercises 94 with gelatinized fluid 91 Painless removal of pulp 72 Palladium, characteristics of , 77 influence in alloys 78, 79, 80 Paper, bibulous, absorbent 39 strips for finishing 29 Paraffine for canals 52 Plastics 90 zinc 90 Platinum, characteristics of 77 influence in alloys 78, 79, 80 Pliers, dressing . 39 INDEX. 131 Pluggers. ball end 33 enlarged 92 forces of 33 purpose of 31 triangular foot, with matrix fillings 33 Pneumatic mallets , 37 Points, for grinding and finishing 29 gutta-percha and metal, for canals. /. 51 leather 29 plugger 31 soft rubber 29 wood 29 Polishing powders 29 Portes for strips 29 Practical exercises for devitalizing pulp 74 in amalgam 94 in gold 96 in gutta-percha 92 in oxychloride of zinc 94 in oxyphosphate of zinc 94 in tin 95 in tin and gold 96 Predisposing causes of decay 53 Preparation of cavities, class 1 55, 56, 58, 59 class 2 59, 61, 62 class 3 63, 64 for gold 64 for plastics 64, 66 for tin 64 for practical exercises 64, 66 Preparation of tin for cavities 84 Protection of the pulp 69 materials for 69 practical exercises 70 Pulp capping 69 materials for 70 Pulp chamber and canal 7 Pulp, function of 67, 68 painless removal of. 72 protection 69 protection and capping, practical exercises 70 protection, materials for 69 removal of 47 study of form and location 14, 67. 68 treatment, general consideration 67 treatment, conservative and radical 67 treatment, radical 71 Puny 92 122 INDEX. Putrescent pulp 49 Pyramid, dentinal 55 enamel 55 enamel and dentinal, class 1 and 2 59 Pyrozone 49 Reamer, actions of 26 for root canals 26 Reaming canal 47, 50, 51 Relief line, advantages of 3 Removal of decayed dentine 47 of pulp , 47 of pulp by electrolysis 72 Requisites for students 9 provided by teacher 9 Rubber dam 39 application of 39 applying clamp 44 applying with igatures 44 application without ligatures 44 clamps 35 Rubber clamps, application of 44 hard and corundum 29 tooth forms 92 tooth forms, advantages of 93 Saws, frames 29 separating 29 Sealers, angles and curves in 23 purpose of 23 blade of 23 description of 23 for deep-seated calculus 23 for heavy deposits 23* shaping 16 Sections, cutting 8 cutting longitudinally 7 cutting microscopic 14 duplicate sheets of 8 filing in trays 8 longitudinal aspect shown 11 prints of .... 8 mounting and annotating 9, 10 ' transverse 13 transverse, value of 12 Semicohesive gold 87 Separating teeth, how accomplished 37 Separators, mechanical 37 Serrations 32 Shank, purpose of 23 INDEX. 123 Shavings of tin . . . '. , 84 Silhouettes, printing 10 sample page, longitudinal 11 transverse : . 12 transverse sections, sample page 13 Silk ligatures 39 Silver, characteristics of 77 influence in alloys -. 78, 79, 80 Smooth broaches 35 Soft gold -. 87 Spatulas, forms and uses of 31 Specimen course 97 Spunk 39 Steel, annealing 16 defined 15 filing 16 hardening of 17 and instruments 15 melting point of 15 practical exercises 16 softening of 15 specific gravity 15 temper of 15 temper indicated by color 16 Strips, cloth and paper for finishing 29 Structural anatomy 7 anatomy, microscopic 14 imperfections 53 Surgical devitalization .... 71 Swiss broaches 35 Teacher, duties of 8 outlining enamel 8 Technic laboratory equipment 5 Tenacity in amalgam 83 Terminology 5 Testing amalgam 94 Tin and gold , 89 practical exercises 96 Tin as a filling material 84 capability of polish 85 cavities where employed 84, 85 characteristics of 77 conductivity of 84 density and hardness 84 ease of introduction 84 filling with ropes or ribbons 86 finishing 96 foil.. 84 124 INDEX. Tin, formation of cavities for 85 freedom from chemical action 84 freedom frcm molecular change 85 influence in alloys 78, 79, 80 insertion of 95 instruments for 31 introduction of cylinder fillings 85 making cylinders of 95 making ropes or ribbons 95 practical exercises 95 preparation for introduction into cavities 84 tenacity of 84 Treatment, pulp, radical 71 Trimmers, file 2G lancet 29 Using broaches 50 Wedging materials 39 Wheels, corundum , 29 grinding 29 Wrapping broaches 50 Zinc, characteristics of 77 influence in alloys % . 78, 79, 80 oxychloride of 90 oxyphosphate of -. 90 oxyphosphate with gelatinized fluid 91 plastics 90 f Of There Are several Kinds of Porcelain Teeth. But none Are so Well adapted For the dentist And His patients As those Produced by H. D. Jusxi &> SON, PHILADELPHIA. CHICAGO. They excel all Others In quality And utility. They Are very cheap In price, and Supplied By dental dealers Throughout The World. H. D. JUSTI & SON, PHILADELPHIA. CHICAGO. UNIVERSITY OF CALIFORNIA LIBRARY Los Angeles This book is DUE on the last date stamped below. Mffl'i i1 Pi HI lira APR 1 6 i BIOMED LIB. APR 2 RECT BliiMD FEBlJ'f 3ioMFr> i IT* 6 JAN 3 11986 v RtCD Form L9-116m-8,'62(D123 r 88)444 AV- -2^ > V^ 1158 00635 9888 A 000 387' ' ^ '^