Pennsylvania Association of Dental Surgeons. [Volume: 2, Issue: 10, May, 1861, pp. 548-558]

PROCEEDINGS OP DENTAL SOCIETIES.

553

One of the main arguments urged by the opposers to its use is, that it
imparts to the tooth its coloring properties, disfiguring and destroying
the beauty of their texture. This, indeed, is a very serious objection,
and is sufficient of itself to condemn it, if the argument be founded on
truth and justice; but may not this result be due more to the impurity of
4he materials, or to the presence of their oxides, or the manner of their
combination, rather than to any action directly upon the materials themselves?
That teeth are, and have been shamefully discolored by it, is a fact,
and from this its use has been abandoned by some, and by others,
whenever employed, restricted to molar teeth and those very far gone in
decomposition.
IHe thought much of the discoloration arose from the impurity or
degeneracy of the materials, as he found no free or combined acids in the
secretions of the mouth that would act to any extent upon pure mercury
or silver. These articles, especially the mercury of commerce, is found
quite impure, and the silver usually very much oxidized at the time of
using, consequently entertained the idea that the coloration was very
much due to these circumstances. While the secretions of the mouth do
not act readily upon pure mercury or silver separate or combined, the
action must. be very considerable upon their oxides, and was of the
opinion that could something be employed to remove these oxides at the
time and after mixing the materials, the coloring properties of the mixture would be mostly if not entirely removed. He was satisfied that
alcohol would not entirely do this, yet it removes much that is impure.
Nitric acid is the only acid that acts to any extent, either upon pure mercury or silver, at a temperature at all permissible with the safety of the
oral structure, and not being found in the secretions of the mouth, therefore coloration is not due to acid reaction. Strong acetic acid used with
articles of food, by its constant repetition may slightly tarnish their surfaces, but nothing further. Coloration may be due to galvanic action
induced by the saline secretions of the mouth, in the oxidation of one of
the baser metals, or to the presence of sulphocyanuret of potassium in
the salivary secretions.
In regard to its toxical or injurious effects upon the system, was inclined to question if not wholly doubt any such influence, and concurred
in the views advanced by Dr. McQuillen, that he had yet to see the first
case of alveolar abscess, ptyalism, etc., due to the presence of mercury in
the amalgam. It is well known that mercury uncombined is inert, and
equally so must it be when combined with silver or tin. The proto-chloride
of mercury (calomel) and deuto-chloride of mercury (corrosive sublimate)
are formed from the sulphate of mercury and muriate of soda, triturated
and sublimated. As this process cannot very well be carried on in the
mouth, it is hardly supposable that they are elaborated to any extent.