Page 368 - My FlipBook

366 COMBINA TION FILLINGS.

gold to bo folded or crimped together, to tliree-qnarters of tin and one-
qnartcr of gold. A convenient way of })reparing " tin-gold " for use

Fig. 345.

Foil crimpers.

in medium-sized cavities is to take one-third of a sheet of No. 4
tin foil, upon which one-third of a sheet of No. 4 non-cohesive foil
is laid. It is then placed upon
Fig. 346.
crimpers (Fig. 345) and drawn into
an evenly folded mass (Fig. 346).
This is to be cut into lengths
suitable to be used for the cavity in
Crimped tin-gold.
hand. These pieces can be doubled
to make blocks, or rolled around a broach into cylinders, if desired.
For larger cavities one-half, two-thirds, or even a whole sheet each
of the tin and gold foils can be used. For very small cavities, one-
quarter sheet of each may be sufficient.
If it be a fact, as often claimed, that tin has peculiar preservative
qualities as a filling material, it will be best to so crimp or fold the
" tin-gold " that the tin will be on the outside, in order that it may be
placed against the cavity walls.
To obtain good results with this combination, it must be used with
the same care and accuracy that are required for working gold. It is
very tough and soft, and can be worked with great rapidity by an
expert. For method of using see chapter on Non-cohesive Gold, and
work " tin-gold " as there described for non-cohesive gold.
After a filling of " tin-gold " has been in for some time it will often
be found to have changed in character, and instead of being a mass of
malleable metal, as it was when put in, t(.) have become hard and brittle^
closely resembling amalgam, but, unlike it, will not stain or discolor
the teeth.
" Tin-gold " is recommended for use in the temporary teeth, in
occlusal and buccal cavities of molars, especially in teeth of poor qual-
ity, and in the mouths of young patients. Small approximal cavities