Page 132 - My FlipBook

II 6 THE TREATMENT OF TEETH
60 to 70 silver, from 25 to 35 tin, from 1 to 3
gold, and from 1 to 3 zinc. In " Plastics and
Plastic Fillings," (Gth edition, revised 1901) Dr.
Flagg states that gold is valueless as a component
of a dental amalgam alloy, and that this conclusion
was not arrived at before July 1900. The pre-
sumption therefore is, that Dr. Flagg's Contour amal-
gam alloy now consists of silver, tin, and zinc. The
Fellowship alloy, as well as two or more others,
that have sprung into existence since the publi-
cation of Dr. Black's experiments, consist of silver,
tin, copper, and zinc. An analysis of Fellowship
alloy gives silver 67"73, tin 26'33, copper 4*71,
zinc 1*23 ; and some other alloys are almost
identical.
The alloy to which the name True Dentalloy has
been given by the makers, is said to consist of silver
72-5, and tin 27'5. The analysis of an alloy will
not give the exact proportions of the metals that are
put into the crucible, owing to some slight loss that
occurs during the melting. It is also stated that a
good formula will not necessarily give a good alloy,
owing to loss of metals that may occur during melt-
ing, and uneven distribution of the metals in the
ingot.
Dr. Flagg considers that his Submarine alloy
makes—owing to the copper it contains—an emi-