Page 253 - My FlipBook

GOLD— TIN. 251
Finally, the fact must also be recognized that in cases in which the
character of the structure of the teeth raises a question as to the adapt-
ability of gold, the physical and nervous resistance of the patient is
generally below that which would enable him to endure the ordeal
connected with the thorougli completion of the work in harmony with
the high standard impressed by the continued advancement which has
taken place in dentistry.
The tendency to carles of the teeth is a general consideration to
be held in view in determining the propriety of employing gold.
When the enamel is hard, the dentin solid, and the general tone of
the health excellent, there can be no doubt that the inherent qualities
of gold constitute it the most nearly permanent material. When, on
the contrary, the opposite conditions exist, gold becomes, in propor-
tion to the prominence of the unfavorable states present, the most
questionable material.
No correct conclusion, however, can be reached without consideration
of the state of the oral secretions and of the habits of the patient as
to the care taken of the mouth. The first stage of decay of the teeth
is the softening of the enamel, which is brought about as the conse-
quence of the presence of carbohydrates undergoing fermentation in
secluded positions, which effects the solution of the enamel at these
places and prepares the way for the occurrence of caries of the dentin.
Hence a correct hygienic condition of the mouth is the most important
requirement for the protection of the margins of the tooth adjacent to
fillino^s intended to restore them.
The reaction of the oral secretions in their bearing upon the permanence
of dental operations has also much weight, since, when these secretions
have an acid reaction, as the consequence of the presence of fei'menting
material, this condition favors the continuance of the process. A con-
tinual acid state of the oral fluids, as a consequence of derangements of
health such as occur in impaired digestion or attend the rheumatic
diathesis, should be taken into account. Only an appreciable degree
of alkalinitij can inhibit enamel solution unless the general and local
hv^ienic conditions are favorable.
Tin.—This metal, in the form of foil, shavings, and rolled into
thin strips, while not in much use, should have a wider field than is
accorded it. It possesses great softness, when chemically pure, and
is readily adapted to the walls of cavities for the reason that it pre-
sents less resistance since it does not harden under the mechanical force
employed. For the same reason, when the cavity is overfilled, the con-
densing appliances effect by the lateral movement of the mass a better
and more easily procured adaptation with the cavity walls. For these
reasons it possesses excellent preservative qualities.