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1 62 FILLING MATERIALS
mercury; or transfer it to a piece of cloth or chamois and
wring with a pair of pliers. Pack immediately.
Method of Packing.—Cut the mass into several small
pieces (depending on the size of the cavity) with a flat bur-
nisher. Do not use too large pieces. Pack with serrated
amalgam pluggers, Black's or Ivory's (Figs. 91 and 92). Pack
with steady, forcible hand pressure, condensing thoroughly
one piece at a time. Pack toward the walls, wedging the
several pieces between each other and the walls. If any excess
of mercury appears on the surface during the packing and
wedging process, remove it with spoon or discoid excavators
before continuing. Do not use tin foil or gold foil for this
purpose on account of the danger of forming a new alloy,
possessing new properties. Pack the cavity overfull, and
allow the mass to set for several minutes before removing the
excess. Trim the excess with flat burnishers and knives
toward the margins, leaving the filling carved to full contour
on proximal surfaces, and to proper form on others. The
final polishing is deferred for twenty-four, or better forty-
eight hours, to allow for complete setting. Directions for
polishing are given on page 185.
Cavity Preparation for Amalgam Work varies very little
from that for gold. The various steps as described in the
chapter on cavity preparation should be carefully and con-
scientiously completed. Convenience angles are not necessary
for starting the filling, the usual retention and resistance form
being all that is necessary. Owing to its lack of edge strength,
the amount of bevel of the cavo-surface angle should be
modified as much as conditions will allow.
Matrices.—For filling with amalgam, the presence of four
lateral walls to the cavity is a necessity, to prevent the squeez-
ing out of the mass during the application of the great force
required during the packing process. In cavities lacking
mercury; or transfer it to a piece of cloth or chamois and
wring with a pair of pliers. Pack immediately.
Method of Packing.—Cut the mass into several small
pieces (depending on the size of the cavity) with a flat bur-
nisher. Do not use too large pieces. Pack with serrated
amalgam pluggers, Black's or Ivory's (Figs. 91 and 92). Pack
with steady, forcible hand pressure, condensing thoroughly
one piece at a time. Pack toward the walls, wedging the
several pieces between each other and the walls. If any excess
of mercury appears on the surface during the packing and
wedging process, remove it with spoon or discoid excavators
before continuing. Do not use tin foil or gold foil for this
purpose on account of the danger of forming a new alloy,
possessing new properties. Pack the cavity overfull, and
allow the mass to set for several minutes before removing the
excess. Trim the excess with flat burnishers and knives
toward the margins, leaving the filling carved to full contour
on proximal surfaces, and to proper form on others. The
final polishing is deferred for twenty-four, or better forty-
eight hours, to allow for complete setting. Directions for
polishing are given on page 185.
Cavity Preparation for Amalgam Work varies very little
from that for gold. The various steps as described in the
chapter on cavity preparation should be carefully and con-
scientiously completed. Convenience angles are not necessary
for starting the filling, the usual retention and resistance form
being all that is necessary. Owing to its lack of edge strength,
the amount of bevel of the cavo-surface angle should be
modified as much as conditions will allow.
Matrices.—For filling with amalgam, the presence of four
lateral walls to the cavity is a necessity, to prevent the squeez-
ing out of the mass during the application of the great force
required during the packing process. In cavities lacking
