Indiana University School of Dentistry - Prognosis Yearbook (Indianapolis, IN)

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Il The-qerognnsts : Smnianafimntal Qrollege :-1904 Qmmal 5. The nervous strain on both patient and dentist is lessened. Q T 1 6. Porcelain gives a better masticating surface than metal. 7. Busy patients need not spend so much time in the dental chair. The disadvantages of porcelain are: 1. The friability of porcelain causes' it to fracture readily. 2. It is impossible to bevel the cavity margins to pro- tect the enamel. 3. It is difficult to match the color of the natural teeth. 4. The cement used as a retaining medium may cause a change of co-lor in the teeth or inlay. g 5. The cement Will be dissolved, 'unless there is only a thin film used as a retaining medium. - Porcelain is not applicable for all forms of restoration and it should not be expected to entirely displace gold and amalgam as filling materials. When properly applied and used Where indicated, it ranks first as a filling qmaterial. The indication of porcelain as a filling material may be classified first, according to the condition of the patient, and second, according to the class of cavities. Under the first classification co-me the following: . p I. In the teeth of nervous patients, where it is almost impossible to prepare retentive forms of cavities for gold or amalgam fillings. 2. For those patients, neither young or o-ld, where the shock from the insertion of a large gold filling will almost cause nervous prostration. 3. For that class o-f patients who have a keen apprecia- tion of artistic dentistry and who object to the conspicu- ousness of metallic fillings. ' ' 4. For those cases Where the pericementum and alveo- lar process are diseased, almost excluding any material which requires a great deal of condensation. 5. In teeth Where caries has progressed to such an extent that the pulp- is almost involved and if filled with the metal, -the irritation caused by thermal changes will cause death of the pulp. ,

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I 'Erbs prognosis Zlnniana Dental Qteilegz F1904 annual but if a fad has been an education to- a higher appreciation of dental services, then it has been of -some value. The gold crown fad has passed, but we have learned that badly broken do-Wn teeth can be conserved and tmade useful. Cataphoresis has taught us that a pulp can be anwsthetized by the diffusion of certain drugs. through dentin to- the pulp. So pressure anaesthesia is the result. One of the elements of true dental art lies in disguising the artificiality of the restorationof lost tissue or organs, and he who is able to disguise his art is truly the artistic dentist. If the insertion of porcelain inlays has been car- ried to- an extreme by some of the enthusiastic exponents, their enthusiasm has caused many dentists to- become in- terested in porcelain work, and their esthetic sense has been developed to a higher degree, so that they are now able to practice dentistry in a more artistic manner. 4 p To what extent porcelain will be used for the restora- tion of lost tooth structure depends largely on the dentist and his clientele. 'Before porcelain can be used as a universal material, a large number of dentists will be compelled to ' 1 x develop the esthetic side of their nature. They cannot be- come artists if they are lacking in. esthetic tastes and ap- preciation of the ,harmonies of nature. Much is said about educating the pub-lic to a higher appreciation of dentistry, but the- tendency of the profession to- commercialism pre- vents many artistic operations from being performed. The questions that so often co-nfront us are: What will it cost, and how long will it last ?,' The success of the opera- tion is determined by the price and durability from such patients' point of view. Some of the advantages of porce- lain inlays are: x ' I. Fillings can be inserted which only the expert can detect. a . A 2.' They are no-n-conductors of thermal changes. ' 3. p The margins of cavities filled with porcelain are not readily attacked by caries. 4. The patient is relieved of the excruciating pain of 'adjusting rubber dam clamps fo-rlcavities extending beneath the gum. , p

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y be zient, r the most gold F the most ecia- picu- lveo- erial 1 an with will . GE e rn masts nmana ental Qtnlle e 1 O4 II 1 IJ 19 Q 131 ' ag z 9 annual The classification of cavities where porcelain is indi- cated may be as follows: T I. All cavities in the labial and buccal surface of teeth. 2. Some simple proximal cavities- on incisors and cuspids. - 3. Proximo-incisal cavities, if the cavities can be so prepared that the retentiveresistance will be greate-rthan the stress. A . 4. Cavities involving all or a portion of the incisal edge. 5. Deep cavities on the occlusal surfaces o-f molars. 6. -Proximo-occlusal cavities of b-icuspids and molars, provided a large enough mass of porcelain can be used to withstand the force of mastication. T i 7. Cavities. involving the entire occlusal surface o-f molars. v The contra-indications for porcelain inlays are: 1. In those cavities where the stress will dislodge the filling or cause it to fracture., 'o 2. In all cavities where it is impossible to construct a good matrix because of the inaccessibility of the cavity. i 3. On incisors which are thin labio-lingually through the incisal third. The construction of porcelain inlays involves four sets of manipulative principles: T I. The preparation o-f the cavity. A 2.. The construction of the matrix. 3. The fusing of the porcelain. 4. The setting and finishing of the inlay. Each step presents a number of -mechanical principles which, if not properly observed, will cause an imperfect filling. The failure of many inlays may be attributed to faulty manipulatio-n, and too many beginners attempt the construction of inlays for the mouth before they have mas- tered the technic. That many dentists fail to comprehend the principles by which inlays are retained is' shown by their cavity prep- aration, and when- asked how they expect the inlay to be retained, their answer is, by the cement. .This lack of comprehension may be largely due to the radical statements of some of the porcelain enthusiasts, some of which are as