The daily morning journal and courier. [volume] (New Haven, Conn.) 1894-1907, 1907-08-17
MAKING A PORCELAIN INLAY.
Interesting Processes of an Operation
In Modern Dentistry.

In Modern Dentistry.
This was an upper front too that
had once been filled with gold, but
fresh decay having set in around
that filling it had become necessary
to fill the tooth again. This time, the
dentist said, he thought he would fill
it with porcelain.
All the processes of making a porce-
lair inlay are Interesting. Having drill
ed the cavity in the tooth to its re-
arired depth and shape, the dentist
next proceeds to make a matrix or
mould of it in gold foil, which he is
enabled to do without breaking this
delicate material by the use of bit
of sponge between it and the crowding
tool So he crowds the gold foil down
around within it everywhere to fit in
to the cavity perfectly, and getting the
depth all around the edge Of the mould
SO exactly that the inlay to be made
in it, when set into place, will not on
ly fit perfectly in the cavity, but fit
into it with its edges flush all around
with the surrounding surface of the
tooth.
The mould thus made of the cavity
in the tooth may look like the tiniest
of tiny gold cups, or it may have some
Irregular shape. according to the shape
of the cavity, but whatever its shape,
this mould of gold foil is so slight and
Trim that touch would crush it, and
1t seems indeed as if a breath would
blow it away, as probably it would,
and you may wonder how solid piece
of porcelain can ever be formed in a
mould SO frail and delicate; but it is
all really very simple, as you will see.
Now the dentist takes a small metal
lie holder about the size and shape
of a very small clam SHE'LL which he
fills with powdered asbestos mixed
with water and on top Of this yield
ing material, handling it gently with
a pair of pliers, he sets the delicate
little gold mould, with its closed end
down, resting so on the surface of the
moistened powdered asbestos. This
holder has a lip on one side of its
edge, by which it can be lifted with
a pair of pliers made for the purpose
and serving thus as a handle for it.
Lifting the little saucer now by this
handle this operator rubs on the han
die very gently, as one might draw a
fiddle bow very gently back and forth
on the strings Of a fiddle; a lead PEN
ell might do for this, but he is likely
to use some professional tool with a
chased or engraved handle, whose ir-
Irregularities will heighten the effect
and rubbing gently with this on the
handle Of the holder he communicates
to it and to it's contents and to the
little gold mould on top continuous,
gentle vibrations which, slight as they
are, still cause the mould gradually to
settle and embed itself in the semi
fluid mass In the holder, and this with
out in the slightest changing its shape
These vibrations are continued till the
mould has settled to the required
depth, and then the water is evapor-
ated from the asbestos, and there you
have the little gold mould firmly i'm
bedded in practically solid material
and ready for use.
The inlay will be made In the mould
from porcelain powder. Porcelain
powders for dental use are made by
the manufacturers of dental supplies
In endless variety of shades, so that
ut Is easily possible to get a powder
whose finished product will match any
TOOTH Then dentist has a great assort-
ment OF teeth made from porcelain
powders these all named or numbered,
and he matches up your tooth with,
one of these and uses for the inlay the
powder of the corresponding number.
With the little gold mould all ready
the operator now mixes a sufficient
quantity of the porcelain powder with
alcohol to give him the material in a
plastic FORM while at the same time
the alcohol will evaporate quickly. He
vets also the asbestos in the mould
holder, to keep that from absorbing
the alcohol in the porcelain powder.
And now with his porcelain in work
able form he fills the mould with it,
to make there the shape that is to
be set into the tooth, and then he pro-
ceeds to fashion in the pdastlc mater
ial it's outward part. This may be
simply a slightly rounded surface, for
an inlay that is to go into the flatter
part Of tooth, or the inlay may in
clude an edge or corner Of a tooth, or
both; but whatever the outward part
may be the operator so moulds and
fashions it that it will continue and
complete naturally the contour of the
tooth into which the inlay is to be set.
With the modelling thus finished the
inlay is ready for the final process
and now, with the holder, mould and
all, it is put into tiny electric oven,
out of which after a suitable time it
is taken, baked into a solid bit of
porcelain, the inlay completed.
1t is set in place with cement; and
so perfectly is porcelain inlaying now
done that except upon the closest in
sreetion 1t may be impossible to tell
in an inlaid tooth where the natural
tooth ends and where the inlay begins;
nice operation in modern dentistry.
New York Sun.
American Manufactures Abroad.