Page 157 - My FlipBook

FILLING TEETH 141

and non-absorbent—while the oxyphospliates are
considered to make leaky or absorbent root
fillings.
As far as filling cavities is concerned, there is no
question as to the superiority of the oxyphosphates,
notwithstanding the more or less temporary or
ephemeral character of any white cement hitherto
produced. In mixing these fillings a little of the
liquid and a little of the powder are placed on a
glass or porcelain slab, and the powder is gradually
worked into the liquid, and then more powder is
added by firm rubbing with a stiff spatula until a
putty-like mass is produced. The mass should
then be rapidly inserted and pressed to place in
the cavity, and the sm'face trimmed to shape as
it sets.
Whatever may be said as to the value of mixing
the liquid and powder in such proportions that an
exact chemical compound results, it must be ad-
mitted that this can rarely be accomplished ; and
experience shows that the most durable fillings are
those in which the liquid has been made to take up
as much of the powder as possible. Too much
powder will, however, produce a crumbly mass, and
the manipulation should produce a putty-like mix
that is, on the one hand, sufficiently stiff, and on the
other, sufficiently plastic, to admit of being readily