Page 188 - My FlipBook

172 THE TREATMENT OF TEETH
The rigidity of platinum compared witli gold, and
its ability to stand great heat without warping, are its
advantages. A platinum matrix is not so likely to be
distorted in removal from a cavity, and in very many
cases there is no necessity to invest it. The pro-
bability is that any one who can make a perfect
matrix with platinum will prefer that metal to gold
;
but it is equally probable that few men who appreciate
the Jenkins* porcelain will take the trouble to acquire
skill in the use of platinum, and of those who do
give platinum a fair trial, only a small proportion
will obtain as good results as they are able to do
with gold. Platinum is manipulated in the same
manner as gold, except that the former requires
more frequent removal and reannealing, and a more
thorough and prolonged use of the burnisher.
Williams' No. 30 gold-foil is generally preferred
for inlay work. The makers of this foil have
recently brought out a gold specially prepared for
inlay work, to which they have given the name of
" Crescent Gold " ; though styled No. 30, it is thicker
than the No. 30 foil, the thickness of which is
about o-ttVo- of an inch. By reason of its thickness,
it is easier to pass beyond cervical margins than
the thinner foil, and it can also be removed from a
cavity with less chance of distortion, but it is not
so easily adapted to the margins unless a burnisher