Page 159 - My FlipBook

SILICATE IN THE MAKING OF A FILLING 155

form. Prior to adjusting the rubber dam, the color or combination
of colors should have been selected, as the opinion formed after the
rubber dam has been in place for a short time is worthless as a guide
to the proper shade to be used. During the early experience with
this material, with each operator, the shade guide should be fre-
quently used as an educator, but in a few months, the operator should
begin to be so familiar with the resulting colors that no shade guide
is necessary.
Making the Filling. ^Yhen cavity preparation is completed, the
proper material and instruments for making the filling should be

Fig. 92.—A suitable slab and spatula for working silicate. The slab should be thick and
heavy in order that when chilled it will remain at a low temperature during the mixing of
the silicate.
placed in a handy position. Absolute cleanliness is imperative, par-
ticularly during the process of mixing, as otherwise the filling when
completed will not be chemically pure. The mixing slab should al-
ways be kept scrupulously clean, should not have a scratched sur-
face and should be without color. This last point is to avoid any
effect color could have on the judgment as to the shade desired. A
good slab is produced by taking a large-mouthed bottle and filling
it with cold water, or even ice water, in order that during manipula-
tion the material may be held at a low temperature. Before using a
thick glass slab (Fig. 92) chill to a temperature of 60 degrees or a
little below. The temperature feature in this manipulation is of
importance. With nearly all of the processes in the filling of teeth
wherein the dentist depends upon subsequent chemical action for