Page 228 - My FlipBook

224 CLASSIFICATION OF DECAYED CAVITIES.

other; the undercutting at the crown wall will be less
than in anterior proximal cavities; and the cervical
wall should have the same general form as in other
cases. In this latter there should be made, at differ-
ent angles, pits for retaining-points—three, if the tooth
is a molar, and two if a bicuspid. For making these
pits, Merry's drill will be found more convenient than
any other instrument.

Preparatory to introducing the rilling, the same ap-
pliances should be used to protect the cavity from
moisture that have been indicated in modification first
of class third. Crystal gold makes a better beginning
for these fillings than foil; and hence the retaining-
points should be filled up with it, and an attachment
made from one to the other; on which foundation
adhesive foil may be built, almost up to the crown
wall of the cavity, and then the remaining portion

filled from the bottom to the orifice, when the sepa-
ration has been made by a V-shaped space, the filling
should have a single plain surface, which will be at a
greater or less angle with the axis of the tooth, accord-
ing to the greater or less portion cut away in the
separation. It is impracticable to build these fillings
up as some of those in the anterior proximal cavities
may be, because of the difficulty of thoroughly con-
solidating and finishing their proximal portions,
especially near the neck of the tooth; though the