Page 350 - My FlipBook

348 COMBINATION FILLINGS.

occlusal cavities, may be used in the same manner in simple approximal
cavities in the molars and bicus])ids, and even in the six front teeth,
when the cavities arc so situated that the amalgam docs not show.
AVlien used in the front teeth the cement should be allowed to remain
very near to the edges of the cavity. The amalgam need not be
more in amount at this point than the thickness of an ordinary

Fig. 324.

Cement and amalgam fiUing in an incisor. The surplus cement has been removed and the fill-
ing is now ready for the finishing portions of amalgam : a, enamel ; b, cement ; c, amalgam.
visiting card (see Fig. 324). For the front teeth very light colored
amalgam should be selected, as color is of more importance than
strength.
In the temporary molars this combination can be used, frequently,
with the greatest satisfaction, especially in those shallow approximal
cavities where but little undercut can be obtained without exposing the
pulp. The cement should be used quite thin, and the amalgam worked
into it with a burnisher, or rounded instrument, forcing the cement to
a feather edge at the margins of the cavity. In cases of this kind resto-
ration of contour should not be attempted, as the force of mastication
might serve to fracture the cement and dislodge the filling. In this
manner many troublesome and difficult cavities can be successfully
treated, and teeth made to last their allotted time that would otherwise
be prematurely lost.
In Compound. Cavities.—A more extended description will be
necessary for the treatment of compound cavities in the bicuspids and
molars, especially where it is desirable to* restore contour. In these
cases a matrix is often a necessity. There are many matrices that may
be used successfully, but, as they are described in other parts of this
work, only one need be mentioned here. This is selected on account of
being almost universal in its ap])lication. It can be made from any
metal not acted on by the mercury contained in amalgam. German
silver is inexpensive and seems to meet every requirement, and is,
therefore, recommended. For ordinary use it should be from No. 35 to
No. 38 gauge. If stiff it should be annealed, so as to be readily bent to
the form of the tooth. It can be easily polished so as to reflect light