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116 THE TECHNICAL PROCEDURES IN FILLING TEETH.

Or two cylinders may be used that have breadth enough to fill
the space from buccal to lingual. Do not condense the non-
cohesive gold before beginning with the cohesive. Merely
adjust it in position with gentle pressure, and then condense it
by building cohesive gold upon it. Then proceed as in all
cohesive gold work, except that after the filling is otherwise
finished the gingival portion should be very thoroughly con-
densed from the surface.
The reason that non-cohesive gold is safer in this position is
that there is less disposition to curl from the margin, and if there
is any disposition to curl from the margin it is easy to make it
tight by this after-condensation, because if not tight it moves
readily under the blows of the mallet, while cohesive gold does
not. Generally a considerable quantity of non-cohesive gold
may be used in this way and greatly reduce the labor of making
the filling.
This plan of filling is especially adapted to proximate cavities
in the bicuspids and molars. These fillings, as we prepare the
cavities, are not anchored in the proximate portion of the cavity,
but in the step cut in the occlusal portion of the tooth. The
filling is supported against the force of mastication upon the
broad, flat gingival wall as a seat, and when non-cohesive gold is
laid upon this in the manner indicated and condensed by packing
cohesive gold over it, it h^s all the supporting strength of the
complete cohesive gold filling.
This plan of using non-cohesive gold is not so well adapted
to proximate cavities in the incisors and cuspids, for in these we
have not the opportunity to make strong occlusal step anchor-
ages, but must depend upon the gingival wall and its angles in
part for the strength of the anchorage. To use non-cohesive
gold upon the gingival wall would materially diminish the
strength of this anchorage. The use of non-cohesive gold upon
the gingival wall of proximate cavities in the incisors is not so
much needed, for the reason that they are in much plainer view
during the progress of building the filling.
Strength of the Bite.

In the consideration of the strength required in fillings, the
strength of the bite, or the power with which the teeth may
be closed upon food, is a matter of first importance. This is