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FILLING WITH GOLD. 255

ment of tlie pair can ))e brought parallel with the plane of
any wall of a cavity. The dimensions 10x5-3-3 and 5x10-3-3,
are particularly suited for use in proximal cavities of the
incisors. Those of the dimensions 12x6-5-10, 6x12-5-10 have
the shank contra-angled, suiting them especially to the build-
ing of gold in proximal cavities of the bicuspids and molars,
which will be more fully explained later. See Figures 344,
347. Both of these pairs have the face rounded, or convex,
on the longer dimension for the purpose of severe packing of
gold without chopping into it. By rounding this dimension, the
first impression on a fairly solid bit of metal is on a limited area
of the face of the point, but immediately this gives way, a
larger area is engaged which prevents it from sinking deeply
into the metal. Of the three round points, the 5-10-3 is espe-
cially suited to starting fillings in small convenience points,
and for special uses by hand pressure, or for any purpose when
severe condensation with light pressure is desirable. The area
of the point — .196 square millimeters — is too small for use in
the general building of gold. The 7Vi;-10-3 has a greater area
— .44 square millimeters — and may be used in the larger
convenience points. It is suited to some positions of general
building of gold in the work in incisor teeth, and, occasionally,
in other positions when the stepping process in building against
walls is not necessary. The 10-10-3 (round) may be similarly
used in general gold building in bicuspid and molar cavities
in which heavy malleting may be employed. This plugger
face — .78 square millimeters in area — is the largest plugger
point that should be used in the automatic mallet. With the hand
mallet used by an assistant, more force may be employed, and,
in a few selected positions, an instrument with a larger area
might be used. The area of the parallelograms 12x6 and 6x12
is .72 square millimeters. A pair of parallelograms 14x8-6-10
and 8x14-6-10, with an impacting area of 1.12 square milli-
meters (not included in the illustration) is desirable where
much non-cohesive gold is used in proximal cavities in bicus-
pids and molars, especially for placing and the first slight
condensation of the non-cohesive gold. In especially favorable
cases, these may be used with very heavy blows of the hand mal-
let in gold building. The area is too large, however, for general
use. Also a pair of points 12x6-3-3 and 6x12-3-3 (not illus-
trated) are very excellent instruments for much of the gold
building on approaching margins in occlusal surfaces.
The bayonet form will sometimes allow a better angle of