Page 131 - My FlipBook

COHESIVE GOLD IN THE MAKING OF A FILLING 127
The shaping should be done Avithout bringing the gold in direct
contact with the fingers, and all manipulation and cutting should be
done previous to annealing.
The Application of the Foil. In whichever form the foil has been
shaped, it should be so placed upon the surface of condensed gold
that the leaves lay flat. If the pellets are placed so that the leaves
of gold are crumpled in packing to place the specific gravity will
not be as great in the finished filling. Neither will the cohesion be
as perfect.
Sheet gold has left in it a certain amount of spring even after an-
nealing that has to be overcome if folded. The less handling of the
sheets in folds when packing the better the result. The gold should
be grasped by the carriers with as small a bite as possible to prevent
precondensation and carried to the position desired and condensed,
with no attempt to shift its position by pushing or poking it around
over the surface.
If the pellet is placed near a wall, it should be placed so that it
lies fully against that wall that it may be crowded for room when
condensed. Short of this will hinder the wedging principle in pack-
ing. If the new pellet is to come out to contour it should reach
slightly beyond contour and be burnished back to contour with a
flat-faced steel burnisher.
The Forces Used in Condensing Cohesive Gold. There are two
principal forces used in condensing cohesive gold, hand pressure and
blows from the mallet. These may be either alone or one following
the other or in combination; the last named is the most popular, the
least taxing on patient and operator and produces as great specific
gravity in less time. However, the best results are obtained by us-
ing each method at given times in the process of building most fillings.
To Illustrate. Hand pressure alone should be used in the filling
of convenience angles. Also when on account of position the force
must be applied at nearly a right angle to the wall against which
the gold is being condensed, as in starting a filling and when cover-
ing the seat of the cavity with the first one-half millimeter of gold.
With the plugger point pointing directly at a dentinal wall, with
a thin layer of gold between, the elasticity of the dentine causes the
gold to rebound when struck a blow Avith the mallet. In such posi-
tions the closest adaptation is secured by hand pressure alone which
should be applied with a rocking motion secured by swaying the
outer end of the plugger from side to side for a distance of, say one
inch, at each change of position.
Hand Pressure Alone is also of most service Avhen packing gold