Page 198 - My FlipBook

1 82 THE TREATMENT OF TEETH
then the indicator turned back one point, so as
to get rid of the increased heat that so often
follows svvitching-off the current when complete
fusion is reached ; sufficient heat will remain
to safely complete the fusion. If necessary, the
fusion may be observed with a magnifying-glass.
The Heat Regulator is considered to prolong the
life of the furnace by lessening the number of
" burns out." The Jenkins gas furnace, while per-
mitting an exact regulation of heat, and enabling
one to easily carry out Dr. Jenkins' directions as to
fusing—viz. to bring the heat up to the point when
fusion begins, and hold it there until the fusion is
completed—has the disadvantage of necessitating a
cover for the tray in which the inlay is fused. The
small opening in the side of the tray through which
the fusing is observed renders it somewhat difficult
to see exactly what is going on. This is particularly
the case on dark days, or if an inlay is made in the
evening. Many dentists-— ^especially if they have
keen eyesight—find the Jenkins furnace answer
their requirements perfectly. The Dall gas furnace
is so constructed that the flame never enters the
muffle, and consequently no covering up of the
tray is needed.
The best-fused dental porcelain is obtained by
gradually and slowly heating up the body until the