. The science and practice of dental surgery. the naturalbulge of the natural crownmust be more than re-moved. This is to allowthe artificial crown to bepushed on when beingfixed, so that the cervicaledge of the artificialcrowai will grip quiteclosely and form no pro-jection. Wliether or not thecervix, or the part that isto be gripped, is thelargest part, can be deter-mined by passing a loopof binding wire in a dentimeter round it,and tightenmg it up bytwisting. If the wire canthen be lifted over theremams of the naturalcrowai easily, no furtherreduction is effect the reduction,th
. The science and practice of dental surgery. the naturalbulge of the natural crownmust be more than re-moved. This is to allowthe artificial crown to bepushed on when beingfixed, so that the cervicaledge of the artificialcrowai will grip quiteclosely and form no pro-jection. Wliether or not thecervix, or the part that isto be gripped, is thelargest part, can be deter-mined by passing a loopof binding wire in a dentimeter round it,and tightenmg it up bytwisting. If the wire canthen be lifted over theremams of the naturalcrowai easily, no furtherreduction is effect the reduction,the buccal and lingual sides can easUy be trimmed down with car-borundum wheels moistened with dilute lysoformand sprmkled with fine carborundum powder;and the approximal sides can be cut awaywith diamond discs dipped in the same. (For Fig. -MitcheUs Root Trimmers.(Dental ManujacturingCo., Ltd.) 562 technique of use of diamond discs interstitiallysee p. 551.) Overhanging enamel can be pulled off easilywith Cases enamel-removers (see Fig. 681),. Fig. 683.—Enamel Chisels for shaving approximaledges, chiefly by a pulling action. {S. S. White Dental Manufacturing Co.) and where the tooth is carious or brokendown level with the gum, overlianging enamelmay be pulled off with a sharp straight-necked scaler, or where there is roomfor it, with the more powerfulinstrument of the same shapedesigned by Mitchell (see ). All these instrumentsare used with a jDuUuig actionin a direction a^ay from thegum. Small stones and fissure-burrs will sometimes assist inremoving corners, and theflexo-file will sometimes berequired, particularly for theposterior surface of the secondlower molars. The flexo-fileshould be bent at an angleof 30°, and the part notactually engaged in cuttingshould be Avrapped ui bibulouspaper to protect the corner ofthe mouth. There is a usefulholder by Ivory for holdingsmall pieces of flexo-file at thecorrect angle (see Fig. 684).He also makes a useful setof ri
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectdentistry, bookyear19
