Page 68 - My FlipBook

METHODS OF FILLING TEETH.
54
In mixing the material, the method must depend upon the use to
which it is to be put. If a permanent filling is desired, put the powder
and liquid upon the slab separately. With a clean, smooth spatula
stir a little of the powder into the liquid until it is incorporated, pro-
ducing a thin but well-mixed material. Add more and more of the
powder until a thick, smooth cream is produced. This, of course, is
still too thin to be used as a but no more powder must be added.
filling,
With the spatula continue to work the mass, when it will soon be
observed that it to thicken and ball up on the slab. It now
begins
has a sticky quality, and may be used if it is necessary to depend upon
adhesion to the cavity wall. If this is not the case, further working
will produce a mass which may be taken between the fingers and
worked as we do gutta-percha. Made into a roll, and cut into pellets
with the sharp edge of the spatula, it is in a most convenient form to
be packed into a cavity.
If is to be used for a crown, it should be simi-
oxyphosphate setting
larly mixed, and used at the creamy stage without further kneading.
For temporary purposes, where it is desirable that the filling may be
removed at a
readily subsequent sitting, as, for example, where it is
employed to cover an arsenical dressing in a shallow cavity, after the
creamy stage, instead of kneading to produce thickening, continue to
add the powder until the consistency is suitable for use. A mass thus
made may seem the same as the other, but really it is quite different.
There is an excess of the powder, and after hardening it can be more
crumbled with a excavator.
readily away sharp Thus there is a vast
difference between the preparation for permanent or for temporary
purposes. May not some of the failures recorded against the material
be more properly attributable to its faulty manipulation ?
It has been advised that during the mixing some germicide should
be worked into the In this oil of cloves and other medica-
filling. way
ments can be stirred in with no apparent harm to the material. More-
over, the odor of the disinfectant will be noticeable very long after, but
whether there be any advantage in the process remains to be demon-
strated.
Oxyphosphate as a filling- material has many uses, the most impor-
tant of which is as a mass to be interposed between a metal filling and
the tooth itself. It must be remembered that save in rare cases
gold
or amalgam furnishes no support to frail walls. In fact, the metallic
filling depends largely upon the strength of the cavity walls for its
permanency. The oxyphosphate, because of its adhesion, does sup-
port frail walls, and therefore is peremptorily required in all such cases.
Unlike gutta-percha, there need be no limitation as to the quantity
used, save that the cavity above it must be of a shape which shall be
retentive for the metallic In these cases
filling which is to cover it.