Page 196 - My FlipBook

i8o THE TREATMENT OF TEETH
as possible. By drying with blotting-paper the body
shrinks or settles down better in the matrix, and
more can then be added. By this means the matrix
at each fusing contains more body than if alcohol
is used, and the number of firings is reduced. It is
easier to paint to a smooth surface if water is used.
It is also more difficult to prevent the mix slopping
over the margins, and this leads to much careful
scraping away of the overlap and much careful
brush-work to paint back to an exact margin, with
a probability of not always painting back far enough,
and consequently producing an inlay with raised
edges. Equally good results can, however, be
obtained with either water or alcohol. Those
who have the electric current laid on generally
prefer an electric furnace, though a gas furnace
answers equally well ; reliable gasoline furnaces
are now made, but at the present time they seem
to be better adapted to high-fusing bodies. The
advantages of an electric furnace are the absence
of noise, odour, and heat radiation, and the fact
that no bellows is required, as with gas furnaces.
An electric furnace may be used in the operating
room, or even in a drawing-room, without the
slightest inconvenience to any one.
The small Mitchell Electric Furnace (Fig. 11)
is generally used in this country, and is a very