Page 71 - My FlipBook

MANIPULA TION OF AVAL GAMS.
57
while under the action of the ball of paper a hard filling is produced
at once. In large cavities a burnisher may be used over the paper, to
exert more force than can be attained with the foil-carriers.
is filled, the next which
When the cavity step is to follow the process
I say will prevent shrinkage. Indeed, it will do more, for it win
"
a handsome white" color which contain a
preserve foryears. Alloys
large proportion of gold have not proven successful. Nevertheless it is
gold upon which we must depend for this most desirable improvement
in amalgam fillings. Take gold foil No. 3 (No. 4 may be used, but
the thinner grade is preferable), and tear it into small pieces without
or When the tooth has been filled with the
folding rolling. amalgam,
place upon it a piece of this thin foil. Then with a warm, smooth
burnisher gently stroke the gold till the mercury in the amalgam
absorbs it. This is not the old scheme of using tin to extract mercury
from an In that method the tin does not enter the
amalgam filling.
but acts in removing the mercury, as a sponge does in
filling, sopping
up water from the floor. The gold, on the contrary, must be forced
into the filling, so that it changes the surface into an amalgam of which
is a
gold component part. Gold is to be manipulated in this way,
upon and into the amalgam, until it will no longer be absorbed. This
can be continued until the surface of the filling is quite hard, and even
golden in color. This color will not be retained after the crystalliza-
when at a will be found
tion, but the filling polished subsequent sitting
of fine texture, and will receive a mirror-like finish.
Where a large contour is to be made, involving say two or three
of a molar, an excess of is to be used, and then when
cusps amalgam
the gold is applied a density will soon be reached which will allow the
to carve the excess of material and
operator up cusps, by removing
forming sulci, after which more gold is to be burnished into the filling
set. A
until the surface is apparently large filling of this character
may be dismissed with little fear of seeing it crushed into shapelessness
at a subsequent visit. Moreover, it is much easier to trim up a contour
than to be
while the material is thus semi-plastic obliged to defer this
It thus becomes that if the best results of
for another day. apparent
amalgam are to be reached by burnishing gold into its surface, we
cannot hope for the most perfect fillings when we use a matrix, and do
not obtain a separation of the teeth in advance of the filling. This is
one more the matrix, which I have said is useful
only argument against
only with amalgam, whereas now we see that even with this material
it has its disadvantages, since it prevents the burnishing of gold along
the approximal surface.
There is another method of manipulating amalgam to which I will
allude, since it is little known, though I do not care to take the responsi-
of recommending it, for the reason that though I have used it with
bility