Page 138 - My FlipBook

METHODS OF FILLING TEETH.
124
Fig. 131 at and between b and c. In filling these cavities the usual
method as described in the previous cases would be followed, save
that we should build against the labial wall before the palatal. But
in the exceptional cases described, where we get but poor retentive
shape along the approximal part of the cavity, we might find it better
to begin in the retaining-pit in the crown and build over and into the
as has been alluded to in the of the use
approximal part, description
of heavy foil.
In making contour fillings in bicuspids where the cavity is similar
to that in a cuspid, shown in Fig. 1 26, no special change of plan is to
be made, save that where there we had a single undercut in the end
of the cusp at e, in a bicuspid we may have one in each cusp, and be-
side resort to the retaining-pit in the sulcus, as in the last figure.
I may now pass to molars, which, though in many respects similar to
some there is so
bicuspids, still present points of difference. Usually
much tooth-substance in all directions that we may almost make the
rule that in each given case we shall decide according to the conveni-
ences, and possible dangers of exposing the pulp. In molars more
than in any other teeth we should be always cognizant of the fact that
the younger the tooth the larger the pulp. I remember that once in a
first superior molar in the mouth of a miss of twelve, I found an expos-

FIG. 132. FIG. 133. FIG. 134.

lire of the pulp in a cavity so shallow that without alteration it would
not have retained a Per contra, late in life we
gutta-percha filling.
often see molars in which the most extensive be
undercutting may
attempted with little danger.
On
general principles I may say that in approximal cavities in
molars I depend chiefly upon two opposing grooves. I prefer that
these should lie along the buccal and the palatal borders, but under
some circumstances they would be situated otherwise. Such a con-
dition is shown in Fig. 132, in which we observe a narrow cavity
extending along the gum-line and partly around the buccal surface.
Such cavities often result from the use of
ill-fitting clasps, though they
may occasionally occur where no clasps or bands have been used. Here
we have a condition
practically similar to one of the cavities in the