Page 134 - My FlipBook

130 OPERATIVE DENTISTRY

will not sufifice to have these made into the form of a round hole or
slot, but they should be shaped up to the distinct wedge shape. This
shape will cause the condensed gold to crowd the elastic dentine on
all sides as it is driven to place and insure the stability of the first
piece of gold. If this small convenience angle is not sharp at its
deepest point, but has a flat wall or seat, the mallet force is pre-
cluded as that flat wall will not permit its use, the elasticity of which
will cause the gold to rebound when struck a blow, whereas when
this point is sharp and the approaching sides leave a wedge-shaped
opening the gold is firmly grasped when driven to position. Atten-
tion to this small detail will make easy starting of such fillings.
As to the Three Plans of Starting Class Two.—The First Plan,

Fig. 74.— Starting cohesive gold, first plan.

and probably the most popular, is to fill one convenience angle, the
one the farthest from the viewpoint of the operator, and while sup-
porting this in position with a suitable instrument build along the
gingivo-axial line angle to the other point angle.
A Second Plan is to fill each point angle separately and join the
two with a third piece of gold laid along the gingivo-axial line angle.
A Third Plan is to start with a quantity of gold sufficient to fill
both point angles and cover the connecting line angle as well as a
considerable portion of the gingival wall next to the axial. This last
plan is one used by some experienced operators and is well to be at-
tempted when working for speed. The beginner will do well with
the first plan.
The Order of Stepping the Plugger in Class Two. With each