The Worthington advance. [volume] (Worthington, Minn.) 1874-1908, 1907-09-20
'APORC|EELA|N' | |

1 One Of the Dainty Operations Ii
Modern Dentistry.
The WAY THE INLAY is MADE.
\ Fashioned In Fragile Gold Lest, the
Matrix 10 Sunk by Vibration In Semi
Suid Asbsstus and the Mold When
Set Filled With Porcelain. @S
+ This was an upper front tooth that
had once been nicely filed with gold,
hut fresh decay having set In around
that filing 1t had become necessary to
iii the tooth again. This time, the
dentist said, he thought he would I'LL
1t with porcelain.
\ All the processes Of making q por-
celain inlay are interesting. Having
drilled the cavity In the tooth to its
required depth and shape, the dentist
next proceeds to make matrix or
mold Of it in gold foil, which he is
enabled to do without breaking this
delicate material by the use Of hit
of sponge between it and the crowd
Ing tool. So he crowds the gold foil
down around within it everywhere to
At into the cavity perfectly and gets
the depth all around the edge of
the mold so exactly that the inlay to
be made In 1t when set into place Will
not only fit perfectly In the cavity, but
1T into it with its edges flush all
around with the surrounding surface
OF the tooth.
The mold 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 it's shape,
this mold of gold foil IL 80 slight and
thin that q touch would crush 1t, and
Il seems indeed az II q breath would
blow It away, as probably It would,
and you may wonder how q solid
niece of porcelain can ever be formed
In 4 mold 90 fran and delicate, but It
Il all really very simple, as you will
bee.
Now the dentist takes q small me-
tallic holder about the size and shape
OF Q very small clam shell, which he
oils with powdered asbestus mixed
With water, and on top Of this yield
ing material handling 1t gently with
q pair of pliers, he sets the delicate
little gold mold, with its closed end
down, resting 80 on the surface OF
the moistened powdered asbestus
This holder has a lip on one side OF
its edge, by which it can be lifted with
q pair Of pliers made for the purpose
and serving thus as handle for IT.
Lifting the little saucer now by this
handle, the operator rubs on the han
die very gently, as one might draw
fiddle bow very gently back and forth
On the strings of a fiddle. A lead PEN
en- might do for this, but he Is likely
to use some professional tool with +
chased or. engraved handle, whose +
iasgulax1ti4s VIII :etshtsn Ne eMef
and, rubbing gently with this on the
handle Of the holder, he com unicates
10 It and to It's contents and to the lit
tie gold mold on top continuous, gentle
vibrations. which, slight az they are.
stnl cause the mold gradually to settle
and imbed itself In the semiduid mass
IN the holder, and this without I'm the
slightest changing its shape. These
vibrations are continued till the mold
has settled to the required depth, and
then the water 10 evaporated from the
asbestus, and there you have the little
gold mold firmly Embedded in pracd-
cally solid material and ready for use.
e. The inlay win be made in the mold
from a porcelain powder. Porcelain
powders for dental use are. made by
the manufacturers Of dental supplies
In endless variety Of shades, 10 that
It is easily possible to get a powder
whose finished product viii match any
tooth. The dentist has great as
sortment 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 mold all ready,
the operator now mixes 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 asbestus in the mold
holder to keep that from absorbing the
alcohol in the porcelain powder.
And now with his porcelain In work
able form he fills the mold with It, to
make there the shape that is to be set
into the tooth, and then he proceeds to
fashion in the plastic material its out
ward part. This may be simply a
slightly rounded surface, for an inlay
that is to go into the fatter part Of
tooth, or the inlay may include an
edge or corner Of tooth, or both; but,
whatever the outward part may be,
the operator so molds and fashions 1t
that it will continue and complete nat
urally the contour Of the tooth in
which the inlay is to be set.
With the modelling thus finished, the