Page 160 - My FlipBook

METHODS OF FILLING TEETH.
146
care should be taken not to undermine and weaken what is to be the
This caution to the antero-
strongest support. especially applies
buccal cusp, which is in danger of subsequent fracture. The case de-
scribed one in which the is supposed to involve the
being depredation
approximal portion only very slightly, it is plain that the dam could
be save in conical teeth.
placed exceptionally short, or abnormally
Therefore I should choose gold as a filling-material. I should start
the at the in the formed at that
filling palatal angle deep dip point,
build backward to the palatal groove, thence over the floor of the
cavity and along the walls, and so around and back to my starting-
place. All the exposed portion of dentine being thus covered, and
all borders perfected, the contour could be rapidly completed by using
heavy foil and fairly large instruments with the mechanical mallet. A
word as to the contour here. As it is not to show, there is no special
object in building the cusp up to the full original height, it being re-
membered that the more gold the weaker the contour. Were this the
buccal cusp it would be more essential to fully restore it, since it would
be to view. But in no case need the exact lines of the
exposed
be An contour will be
original reproduced. approximate sufficiently
serviceable, and will prove more durable than where deep depressions
are made in simulation of the normal sulci.
Where two cusps are absent, if they be the anterior ones, we must
observe the same caution at the buccal groove as was advised at the
and remove weak enamel as far as both of these
palatal, grooves.
Such a cavity prepared for filling is seen in Fig.
FIG. 166. 1 66. The retaining groove a, a now assumes a
half-circle, whilst we have two depressions, one
at each angle, 6, &, and there is a slight undercut
along the standing wall as before. The filling
with gold is practically as in the last case. The
general arrangement of these cavities will be as
of which are
described, regardless cusps lost.
In some conditions it maybe found advisable to
resort to screws, whilst the method shown in Fig. 102 may be adopted
in extreme cases. As long as the approximal surface is only slightly
encroached upon, however, the fillings can be sufficiently anchored
without the screw, or holes cut through the walls, for we could make
the groove and retaining depressions of sufficient depth and strength.
Where three cusps are absent, the groove is extended still further,
and a third depression at the third angle is to be made. With the
disappearance of the fourth cusp we have the groove a complete
circle, four retaining depressions being needed, one at each angle,
and the tooth is filled and the retained exactly as described in
filling
connection with and illustrated by Figs. 161 and 162.
bicuspids,