Page 360 - My FlipBook

358 COMBINATION FILLINGS. —
however, for lioldino; in the filling as a whole, the same as if it were
entirely of gold or amalgam.
Cases may occur where it does not matter whether the amalgam
and gold are firmly united or not ; then, instead of putting the plastic
gold into the amalgam, soft foil may be used against it in the manner
described for the combination of" soft" and "cohesive" golds (page 361).
Having become familiar with the simplest form of fillings of amalgam
and gold, it will be well now to go a step farther, and take up some of
the complications that constantly occur. Even the small amount of
amalgam that is used will sometimes discolor a tooth slightly, especially
if the buccal wall is thin or if the tooth is not of very dense structure.
When there is danger of this discoloration taking place, it can be largely
prevented by placing a medium-sized pellet or fold of
Fig. 340. foil^ known as "gilded platinum," against the buccal
wall of the cavity before putting in the amalgam. This
foil being faced with platinum, Mdiich has but very slight
affinity for mercury, the amalgam can be consolidated
against it with little danger of discoloration following.
On the mesial surface of bicuspids and molars it will
o, Amalgam; 6, uot be cuough, always, to put the gold and platinum foil
gold extend- less of the proximo-
affaiust the buccal wall ; more or
ing on the '^ ^^ • i • •
buccal side buccal surface of the filling being exposed to view i. e.
nearly to the
^^^^^ hia gum margin. ' ' ''
^
if made of amalgam ; consequently, in these cases the
gold must be carried to the cervical wall, as shown in Fig. 340, the
amalgam occupying a triangular space.
Cement, Amalgam, and Gold.
There are many teeth with very large cavities and frail walls, that
can be rendered serviccalde for years and made to look surprisingly
well by the use of this triple combination. For instance, a molar or
bicuspid having lost its pulp and a large portion of its crown, and
occu])ying a conspicuous position, presents to the conscientious denti.st a
serious problem. He knows that if filled with amalgam it will be an
eyesore to every one by its unsightliness. If filled with gold it would
take hours, and exhau.st both patient and operator, and there would be
every probability of the walls soon breaking away and the filling com-
ing out, testifying to the poor judgment of the operator in recommend-
ing such a filling under such circumstances. If filled with cement it
will have to be refilled often, and with each refilling would more than
likely be somewhat weakened. The loss of contour by the wasting away
of the cement will allow the tooth to change position, and its usefulness