Improvements in Artificial Teeth.
Year: 1887

page_text: Improvements in Artificial Teeth.
We ELLIOT HAMILTON SHERMAN, of the city of Grand Rapids, in the county of
Kent, and State of Michigan, one of the United States of America, Dentist, and
JOHN BYRON PARKER, of the same place, Dentist, do hereby declare the nature
of our invention for IMPROVEMENTS IN ARTIFICIAL TEETH, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
Our invention relates to improvements in artificial teeth which are usually made of
porcelain and attached to a support of metal or other suitable material, which is in
turn secured within the mouth in some suitable manner.
Heretofore such teeth have consisted of a single piece of porcelain such as are
known as plate teeth, and shells or facings.
Plate teeth are solid pieces of porcelain of the size and shape of natural teeth
and are attached to a suitable support by means of pins projecting from their lingual
or palatine surfaces. Being necessarily bulky to give strength they permit the
insertion of but little supporting material between themselves and the gums, so that
they cannot be used for the so-called bridge-work, for the reason that the strain of
mastication falls nearly or quite in the direction of the plane of the adjacent surfaces
of the tooth and its support, there is great liability of breaking the pins which secure
the tooth to its support.
Shells or facings have no crowns or grinding surfaces of their own and are intended
and adapted to be provided with the same of metal, which is integral with and a part
of the backing or support. This has been necessary in order to get sufficient strength
of supporting material to form a bridge that would not break under the pressure of
mastication.
As their name implies they are merely an outer facing of porcelain, in a single
piece, adapted to fasten to a tooth otherwise made of metal.
These metallic crowns are more expensive than porcelain, less suitable as a grinding
surface, and do not resemble the natural teeth as do the porcelain.
The objects of our invention are: To provide a tooth less liable to be separated
from its support, also so adapted that both the crown or grinding surface and shell or
outer surface may be made of porcelain and at the same time afford room for a support
[ Price 6d1

page_text: sufficiently strong to constitute a suitable bridge that will not be easily broken: also
to provide a structure that when complete will be materially cheaper and present a
more suitable grinding surface, and a nioro natural and pleasing appearance in the
mouth.
Our invention consists in providing a tooth of two separate pieces of porcelain
consisting of an outer part or facing, and a crown or grinding surface, adjusted at,
or nearly at, right angles to each other and separately attached to a suitable support
consisting of a bridge or plate of suitable material as hereinafter more fully
described.
In the accompanying drawing,
Figure 1, represents the detached shell and crown of our improved tooth.
Figure 2, the same attached to a portion of a bridge or plate."
Figure 3, an elevation of the same as Figure 2, viewed from the face of the
shell, and
Figure 4, a vertical section on the line X, X, of Figure 3.
A, is the shell, and, B, the crown of the tooth, each being a separate piece of
porcelain, and provided with the usual pins, (, or other suitable fastenings for attaching
them to the support, D, which may be a plate, or bridge of any suitable material, and
secured within the mouth in any convenient manner. The surface of the crown, B,
which is in contact with the support, D, is at right angles, as near as may be, to the
direction of the pressure upon said crown, therefore there is but little tendency to
break said crown or separate it from the support, D.
By the described construction we are also able to adjust the position of the crown
relative to the shell, and adapt the tooth to properly articulate with the antagonizing
teeth, without grinding its outer surface.
We also secure within the angle formed by the described crown and shell, sufficient
room to form a support strong enough to constitute a suitable bridge. This support
may extend between the adjacent beveled surfaces of the parts, A, and B, thus making
a perfect joint, and support for the part, B. Said support may be made of other
suitable material than metal, such for example as celluloid, or vulcanite, and can be
adapted to plate or bridge work as occasion requires.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. An artificial tooth consisting of a separate outer part or facing, and a crown or
grinding surface both of porcelain, adjusted substantially at right angles to each
other, and separately attached to a suitable support substantially as hereinbefore
described.
2. As an article of manufacture: porcelain veneers in pairs, consisting of a crown
and an outer facing each provided with means of independent attachment to a common
support, and when so attached constituting in conjunction with such support an
artificial tooth substantially as herein before described.
Dated this 5th day of December 1887.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C.,
Agents for the Applicants.