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CHAPTER XIII.

PL.ASTIC FILLING MATERIALS—THEIR PROPERTIES, USES,
AND MANIPULATION.

By Henry H. Burchard, M. D., D. D. S.

The materials included in the heading of this chapter are — (1)
Amalgam ; (2) Gutta-percha and its preparations ; (3) The basic zinc
cements.
History.—The introduction of the first member of the group was
not prompted by any specific merit that it had been demonstrated to
possess, but was due solely to its properties of easy introduction, com-
paratively perfect sealing and prompt hardening, qualities which appar-
ently recommended its wide and general use to those not possessing the
requisite degree of skill for the successful manipulation of gold foil.
Applied upon a basis of glaring empiricism, with an absence of
technical skill, the material received the prompt and sustained con-
demnation which its abuse had warranted. The steps and phases of
this opposition of the trained and skilled against untrained and un-
skilled operators may be read in the dental journals of from 1846 to
1878 and even after. It was commonly known as the "amalgam war."
The first dental amalgam was that of Taveau, called " Silver Paste."
It was made of filings of coin silver (silver 9, copper 1), combined
with sufficient mercury to make a plastic mass. It was presumably this
alloy which was introduced into America by two charlatans named
Crawcour, under the glittering title of " Royal Mineral Succedaneum."
The discovery of the nature of the paste followed soon after its intro-
duction, which was clearly prompted by the motives above stated.
Thereupon followed a persistent and virulent attack upon the material
and all who used it. Upon less than the merest shreds of evidence
alleged cases of salivation and mercurial necrosis were recorded as due
to the use of amalgam.
That amalgam was still employed by the practitioners of France is
evidenced by the presentation in 1849 of a formula for an amalgam
alloy of pure tin and cadmium by Dr. Thomas Evans, an American
dentist practising in Paris. An amalgam made from this alloy was
found to shrink, and also to stain the dentin of teeth into which it liad
been introduced, owing to the formation of cadmium sulfid. It is note-
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