The Dental cosmos . considerableextension has occurred, are complicated by the proximity of the disto-buccal groove (h). In many cases a large part of the enamel of theposterior part of the disto-buccal lobe has been undermined, and thedisto-buccal groove appears so slight or is so often obliterated by wearthat there is great temptation to ignore its presence. Therefore theline of the enamel margin is placed near the line of the groove, andbreakage occurs in a short time. The rule should be to place theline of the enamel margin along the line of the groove, or beyond it,cutting away the enamel
The Dental cosmos . considerableextension has occurred, are complicated by the proximity of the disto-buccal groove (h). In many cases a large part of the enamel of theposterior part of the disto-buccal lobe has been undermined, and thedisto-buccal groove appears so slight or is so often obliterated by wearthat there is great temptation to ignore its presence. Therefore theline of the enamel margin is placed near the line of the groove, andbreakage occurs in a short time. The rule should be to place theline of the enamel margin along the line of the groove, or beyond it,cutting away the enamel of this lobe entire in the grinding-surfaceand over onto the buccal surface, as illustrated in Fig. 16, unless it isfound to be firmly supported by sound dentine. In the case illustratedI have not found sufficient support for the filling in the dentine of thedistal third of the tooth, and have therefore cut a shallow slot mesiallyinto the central fossa. This is generally a necessary expedient when Fig. 15. Fig. Fig. 15. Lower first molar with distal proximate cavity, a, Mesio-buccal cusp; b, Disto-buccal cusp ; c, Distal cusp ; d, Mesio-lingual cusp ; e, Disto-lingual cusp ; /, Mesial groove ;g, Buccal groove; h, Disto-buccal groove; z, Distal groove; k. Lingual groove; m, Cariouscavity. Fig. 16. Same tooth as shown in Fig. 15, but with cavity prepared for filling, c, Disto-buccal,or fifth cusp, cut away; r, Line of enamel margin extended to the disto-lingual angle; n,Line of intended contour of the filling, showing the contact with the second molar o, andhow the lines of the enamel margins are held away from near contact to render them self-cleansing; p, Slot cut into the central fossa for anchorage. these cavities have been left to be discovered by the patient. When aclose watch is kept by the dentist in charge, such mesial cutting shouldnot often become necessary, for the cavity should be treated whilethere is yet sufficient dentine for anchorage in the distal third of
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Keywords: ., bookauthor, bookcentury1800, bookdecade1890, booksubjectdentistry
