Page 182 - My FlipBook

1 68 METHODS OF FILLING TEETH.

lines a, a, indicate the retaining extensions depended upon for the
whilst in the smaller there is a
larger cavity, merely general undercut,
toward the toward the to
slight crown, and deep enough gingiva
allow the first pellet to be wedged securely, if gold is to be used.
The choice of gold or amalgam might depend, as before, upon the
age of the patient, or it might be decided in accordance with the
met with in the dam, and the amount of moisture.
difficulty placing
The general arrangement of the larger cavity in Fig. 195 is the one
to be depended upon in all ordinary buccal cavities. This is, exten-
sions at the anterior and at the posterior gingival angles, with grooves
following the other borders, decreasing in depth as the crown is ap-
proached. This applies more particularly to cavities resulting from
true caries. Those found under green-stain will be much more per-
plexing. To illustrate, I will give two examples. The first is seen in
Fig. 196, where, the stain having been removed, we find three small
cavities along the gum-border, whilst the enamel
between and around them is more or less decal-
FIG. 196.
cified, as indicated by the stippling. The prepara-
tion of this necessitates the free use of a bur, form-
a which will include the entire
ing single cavity
affected area. This may result in an oblong cavity
along the gum-border having nearly parallel bor-
ders. More commonly, however, the enamel will
be found softened toward the crown along the
sulcus, so that, when prepared, the cavity will be
approximately shaped like the larger one in Fig. 195. A most dis-
heartening condition is where, whilst extending the cavity in the
direction of the decalcified territory, it is found that one or both
approximal surfaces have become affected. The rule, however, is
not to be relaxed, even though the procedure as directed will lead
the dentist around the tooth, thus a com-
entirely forming cavity
This occurred to me once, and I found much
pletely encircling it.
in until I hit a method which led
difficulty placing amalgam, upon
me out of the dilemma. The difficulty was that after packing the
amalgam into the posterior approximal part of the cavity, thence into
the buccal, and so around into the anterior approximal, as soon as I
endeavored to fill the palatal part I found myself dislodging that
already packed. Add to this the inroads of moisture, because of
the fact that I was the and it is seen
obliged to depend upon napkin,
that the amalgam, becoming wet, could not properly be forced back
into I tried at Different but when
place. beginning points, invariably
I came to the circle, di.-,lodgment resulted. I
completing Finally
succeeded thus : I fashioned a band of German silver, somewhat
wider than the I t'le of the
cavity. began by filling palatal part