Page 65 - My FlipBook

FILLING TEETH 49

gold itself, as upon the fact that it lends itself to the
employment of enormous force. The wedge is the
greatest force in mechanics, and it is on the power
exerted by the wedge that non-cohesive gold fillings
mainly depend for their excellence. The force that
may be used is only limited by the strength of the
cavity walls, for the lateral compression of the gold
by means of the wedge does not jar the tooth or
hurt the peridental membrane. It is quite easy to
split off one or more of the cavity walls by wedge
power, and this demands discretion in regulating
the force.
The great difficulty with non-cohesive gold is in
obtaining or producing cavities of the right shape
and accessibility. An ideal cavity may be said to be
one of medium to large medium size on the occlusal
surface of a first lower molar. Here strong walls of
sufficient height or depth can be secured at right
angles to a flat floor. The gold can be readily
inserted in layers parallel to the walls, and the
wedge-shaped plugger can be driven into the gold
at any part parallel to the walls and at right angles
to the surface of the filling.
The holes made by the wedge can be solidly filled
up by drivmg non-cohesive gold into them, and the
most even and thorousrh condensation of this gold is
arrived at, producing a filling that is not only per-
D