form density than when ropes are used. Tapes can
also be made by folding part of a sheet of foil over a thin, narrow
strip of metal. Fold the tin into tapes of different lengths, widths,
and thicknesses, according to the size of the cavity; then fold the end
of the tape once or twice upon itself, place it at the base of any
proximal cavity, and begin to condense with a foot plugger of suitable
size, and if there is a pit, groove, or undercut which it does not
reach, then use an additional plugger of some other form to carry the
tin to place; fold the tape back and forth across the cavity, proceeding
as for cohesive gold. In small proximal cavities a very narrow tape of
No. 10, one thickness, can be used successfully. For cavities in the
occlusal surface, use a tape as just described, generally beginning at
the bottom or distal side, but the filling can be started at any
convenient place, and with more ease than when using cohesive gold. In
any case if the tin has a tendency to move when starting a filling,
"Ambler's left-hand assistant" is used, by slipping the ring over the
second finger of the left hand, letting the point rest on the tin. This
instrument is especially valuable in starting cohesive gold (see Fig.
6). This is the easiest, quickest, and best manner of making a good
filling, relying upon the welding or cohesive properties of the tin.

Many operators have not tried to unite the tin and make a solid mass;
they seem to think that it cannot be accomplished, but with proper
pluggers and manipulation it can be done successfully.

[Illustration: FIG. 6.]

For large occlusal or proximal cavities, the tapes may be folded into
mats, or rolled into cylinders, and used on the plan of wedging or
interdigitation, and good fillings can be produced by this method, but
the advantage of cohesion is not obtained, and more force is required
for condensing. They are, therefore, not so desirable as tapes,
especially for frail teeth. When using mats or cylinders, the general
form of the cavity must be depended upon to hold the filling in place.
To make the most pliable cylinders, cut a strip of any desired width
from a sheet of foil and roll it on a triangular broach, cutting it off
at proper times, to make the cylinders of different sizes.

A cylinder roller, designed by the author, is much superior to a broach.
(See Fig. 7.) When the cavity is full, go over the tin with a mallet or
hand burnisher, being careful not to inju