Page 183 - My FlipBook

BUCCAL CAVITIES.
169
cavity, packing the material part way into the approximal portions.
Next I placed my band in position around the tooth, covering the
amalgam already in position, and allowing the two ends to extend
forward between the adjacent
teeth. Around this band I placed FIG. 197.
waxed flax thread, the ends lying
loose. The condition at this
point
is shown in Fig. 197, which gives
the buccal side of the tooth still
unfilled, the relation of the band
and flax being seen. The filling
was continued from the
posterior
approximal part around into the
buccal, when the band was bent
down over it. Then the anterior
was similarly treated. When
part
both ends of the band were thus
turned down, the flax was tied, securely holding the band in
place,
whilst as it was drawn tight it compressed all the amalgam into the
cavity uniformly and simultaneously, even forcing out a slight sur-
of This was left in Since
plus mercury. position until the next visit.
then I have frequently resorted to this method of tying a band around
an where similar conditions existed, even
amalgam filling though they
have been less extensive. It is a measure where
good precautionary
amalgam is placed in a large but shallow buccal cavity, as well as in
many other conditions of anomalous shape, where, after filling, there
might be danger of fracture before the mass has hardened.
The second of cavities found in connection with
type green-stain
is where the entire surface seems more or less
decalcified. Fig. 198 gives an extreme case.
FIG. 198.
Where the depredation is less, so that the crown
is not so nearly approached, the borders are simply
to be formed into regular curves, and the retaining
arrangement will be the same as in Fig. 195, a, a.
Where the decalcification has been as as shown
great
in Fig. 198, it will generally be wiser, if not actually
necessary, to extend the cavity into the crown, and
then form a groove under all borders. In many
instances this will be made simpler by the presence of a filling in
the crown, which can then be removed.
Only in the smallest buccal cavity, found under green-stain, would
I attempt a gold filling. With the larger, and especially where the
border beneath the I and advise
gingival passes gum-margin, prefer
amalgam. An alloy which has a percentage of copper i:i it has done