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Fig. 218.

Fig. 220.

Figs. 217-220. A series illustrating the mauagenient of a weak disto-lingual angle in an upper
molar. Also a broad contact and the use of separation and restoration with a prominent contact point.
Fig. 217. Upper first and second molars, showing a disto-occlusal cavity in the first molar. The
contact is very broad and close. The teeth are large, angular and strong.
Fio. 218. In uncovering the cavity by chipping away the undermined enamel, it is found that
the whole occlusal portion of the disto-lingual cusp has been undermined and the enamel much
weakened by backward decay. Therefore, the cutting was continued until the cusp was removed over
onto the lingual surface, as shown in this illustration. Notice particularly that the cutting includes
the whole width of the linguo-distal groove, passing over onto the lingual surface.
Fig. 219. This illustration exhibits a more extended cutting of the lingual surface made neces-
sary by deeper burrowing, which may often be treated successfully by this plan.
Fig. 220. The case after the filling is completed. After the cavity has been roughly prepared and
it has been found that the pulp will not be exposed, some time is taken in separating the teeth. Notice
that in Figure 218 the bucco-distal angle as prepared is in contact with the second molar, the surface
of which is very fiat. Then compare this with the relation of this angle to the second molar in
Figure 220, which shows the separation and the use of the prominent contact point.