Page 82 - My FlipBook

78 GENERAL REMARKS ON FILLING.

A mere mechanical mixture would not be an appropri-
ate material for permanent rilling ; and all compounds
of the metals, so far as we are familiar with them, are
unfit for this purpose, by reason of the facility with

which they are destroyed in the mouth.
The next most important property of a material
for filling is adaptability ; by which is meant a capa-
bility of being wrought into suitable shapes for the
purpose,—a facility of being applied and conformed
to the parts upon which it is to be placed. There
are substances that would be entirely indestructible
in the mouth and that would be very desirable in

other respects as materials for filling, yet that are
altogether worthless for this purpose, from lack of
adaptability. Quartz, if it possessed this property,
would be valuable as a material ; but as yet there has
been discovered no method of preparing it in an avail-
able form. On the other hand, many things possess
the property of adaptability, that are lacking in some
other important particulars.
The next important property is, hardness. A ma-
terial may possess all the other suitable qualities, and
yet be too soft. A material should be hard enough
T
not to be broken or w orn away by any pressure or
friction liable to be applied. This property is espe-

cially desirable for fillings in the masticatory surfaces
of the molars and bicuspids. It would, however, be