Page 178 - My FlipBook

164 METHODS OF FILLING TEETH.
even under a as fine as a hair.
strong magnifying glass they appear
This will rarely, if ever, be possible where the beveled edge is
depended upon.
Fig. 189 shows a curious cavity which occurred once in my prac-
tice, and I introduce it because the method of management will be
instructive. This in one of those which are
cavity originated pits
not uncommon upon cuspids, and which result fro'm malformations.
It presented as a small but distinct cavity. On preparing it, to my
I noted that, however
surprise deep I went, the bottom of the little
still showed as a black a mouth-mirror, I examined
pit spot. Using
the palatal side, and there found a corresponding pit, at a point
exactly opposite to that on the labial face. Further exploration dis-
closed the fact that caries starting in each had met, so that when
removed there was a hole from the labial to the
completely through,
palatal surface. Here was a cavity without any bottom to it. The
dam being in place, I stopped up the palatal orifice with oxyphos-
phate, which I allowed to set hard. I then filled the cavity in the
labial face, after which I removed the oxyphosphate and completed
the from that side, succeeding in obtaining cohesion for my
filling
first with the gold packed from the other side, so that when
pellet
finished there was a solid from side to side. This idea,
gold filling
conceived in connection with this particular cavity, has been useful in
many directions. I have elsewhere alluded to it.
The common cavity at the palatal aspect of the anterior teeth is
simple enough, except that great caution is necessary to prevent
This
injury to the pulp. cavity may be met in either central, lateral,
or cuspid, but will most often be found in laterals, occurring in the
sulcus. Its preparation is best shown by a sectional view such as Fig.
190, where we see how near any cavity at this point must approach
the pulp. I prefer a small rose bur to open the cavity, but any soft
decay which may be present must be removed with small spoon exca-
vators. As soon as the limits of the cavity are reached, it will
probably be found to be of retentive shape ; but if not, extension
must be carefully attempted, and must be directed parallel to, or away
from, the walls of the pulp-chamber, as seen in the figure. I have
seen a palatal cavity neglected till it presented as shown in Fig. 191.
If we look at this from a sectional view, as in Fig. 192, we see at once
that the pulp is in danger. Nevertheless, this cavity is quite similar
to that shown in Figs. 186 and 187 as occurring on the labial surface.
As in that case, grooves may be made laterally at a, a, escaping the
pulp. But, unlike the labial cavity, these grooves can be connected
in the palatal cavity, because of the fact that on this side there is a
bulge which permits this procedure in safety. The retaining groove,
therefore, becomes a horse-shoe, as indicated by the dotted lines a, a.