Page 158 - My FlipBook

142 THE TREATMENT OF TEETH
and accurately inserted and packed to place. The
mass may be pressed into the cavity with a broad,
fiat, spatula-like instrument, and then well pressed
to the walls with blunt pluggers. The filling should
be made " all in one piece," and not added to like an
amalgam filling.
Different makes of this cement require different
methods of mixing, and the rapidity of the setting
varies considerably. A method of mixing that will
ofive good results with one make will render another
unworkable ; some can be readily brought to the
putty-like state, by the gradual addition of powder
to the liquid on the slab. With other makes the
addition of powder must cease before the putty-like
stage is even approached, and this thinner mix must
be continually spatulated until it gradually stiffens
up to the desired consistency. There is very little
difference in the durability of any good make of
oxyphosphate cement, and an operator should, as a
rule, select one that he finds easy to mix and work
with. The writer finds, from an observation of the
oxyphosphate fillings he has inserted during the last
eighteen years, that the cervical failure, so often
alluded to, is, in his experience, the exception
rather than the rule. In many cases, cervical
failure may be due to the use of a cement in
either a too stiff, or a too sticky, condition. In the