Page 111 - My FlipBook

OXYPHOSPHATE OF ZINC IN CONTOUR WORK. 97
and crystallization begins at once. Thenceforth the particles of that
of the mass in ex-
portion already position must not be disturbed. If by
force in a wrong direction a
erting part of the filling is fractured off, it
is folly to hope to get a good result by patting it back with a burnisher.
The reunion -will not be as strong as was the original union. It would
be better, where the accident does occur, to remove the
separated
piece, replacing it with freshly- mixed material. To give accurate
direction on this point I must resort to a diagram. Fig. 86 shows a
contour The dotted line shows the extent
large partly completed.
to which it is to be carried.
Whether the remainder of the be packed with bibulous paper
filling
or with burnisher, it is from this point on that
fracture is to be feared. The rule is very FIG.
simple. Pressure must be exerted only in line
with the greatest resistance, offered by the tooth
To the in the direction
itself. pack amalgam
indicated by the arrow a would be safe,
whereas to follow the direction shown by the
arrow b would be to invite failure.
The last essential is to dismiss the as
filling
far advanced toward crystallization as This be best ac-
possible. may
complished by burnishing gold into it, as has been previously described
on page 57.
Oxyphosphate of Zinc. This is a material rarely depended upon
for extensive contour work. Yet there are two special conditions in
which it may be made extremely useful. I once was applied to by an
actress who had lost the corner of a central incisor. The tooth was
and the missing portion extensive. A corner
unusually large, gold
would have been very noticeable to her audiences, and would not be
tolerated by herself. It is possible that at some time in the future
will have been of
porcelain fillings brought to such a stage perfection
that a case of this kind can be readily handled. The lady, however,
came to me long before such work was even advocated. She simply
asked me to restore the tooth with what she termed "bone-filling,"
and I did so, using considerable care to obtain as perfect match to
color as possible, and succeeding fairly well. I replaced this in less
than a year. It must be remembered that as soon as a small part of
the mass had disintegrated the contour was obliterated, so that re-
would be needed more than
filling in this position frequently ordinarily.
The third time that I was asked to fill this tooth, I observed that the
wasting away was mainly from the palatal side, outward. This com-
pelled me to think a little, and I devised a mode of procedure which
I have since followed in similar conditions, with most gratifying re-
an
sults. I first restored the shape of the tooth as before, using
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