IMPROVEMENTS IN THE CON- STRUCTION AND MODE OF FIXING ARTIFICAL TEETH
Year: 1857

page_text: LETTERS PATENT to James Thom, of Lambeth, in the County of Surrey,
Mechanical Dentist, for the Invention of "IMPROVEMENTS IN THE CON-
STRUCTION AND MODE OF FIXING ARTIFICAL TEETH."
Sealed the 14th April 1857, and dated the 30th January 1857..
PROVISIONAL SPECIFICATION left by the said James Thom at the Office
of the Commissioners of Patents, with his Petition, on the 30th January
.1857.
1, JAMES THOM, of Lambeth, in the County of Surrey, Mechanical Dentist,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION AND MODE OF FIXING ARTIFICAL TEETH," to be as follows:-
The object of these improvements is to facilitate the attachment of artificial
teeth, and in such manner that any one touth of a set may be readily removed
for repairs, or be exchanged, without disturbance or injury to any other tooth
in the set. For this purpose a dovetailed groove is formed in the back or
inner surface of the tooth, which groove slides upon a corresponding dove-
tailed stem or wire attached to the artificial palate. In order to strengthen
the tooth, I make the dovetailed groove of thin metal, and of such shape that
some of its projecting parts or edges may be imbedded in the porcelain or
[Price 8d.1

page_text: other material of which the tooth is constructed; the dovetailed groove may
however be formed in the material itself, or it may be affixed thereto by
riveting, or otherwise. When the tooth is slid upon the dovetailed stem, it
may be secured in its place by any suitable cement, the heating of which will
permit the withdrawal of the tooth whenever it is necessary.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Thom in the Great Seal Patent Office on the 29th
July 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
THOM, of Lambeth, in the County of Surrey," Mechanical Dentist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of January, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twentieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said James Thom, Her special licence that I, the said James Thom, my
executors, administrators, and assigns, or such others as. I, the said James
Thom, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
CONSTRUCTION AND MODE OF FIXING ARTIFICIAL TEETH," upon the condition
(amongst others) that I, the said James Thom, my executors or adminis-
trators, by an instrument in writing under my, or their; or one of. their
hands and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within "six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said James Thom, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof,reference being had to the accompanying Drawings, and to
the letters of reference marked thereon, that is to say:

page_text: The object of these improvements is to facilitate the attachment of artificial
teeth, and in such manner that any one tooth of a set may be readily removed
for repairs,or be exchanged, without disturbance or injury to any other tooth
in the set. For this purpose a dovetailed groove is formed on the back or
innersurface of the tooth, whichgroove slides upon a corresponding dovetailed
stem or wire attached to the artificial palate. In order to strengthen the
tooth, I make the dovetailed groove of thin metal, and of such a shape that
some of its projecting parts or edges may be imbedded in the porcelain or
other material of which the tooth is constructed; the dovetailed groove may
however be formed in the material of the tooth itself, or it may be affixed
thereto by rivetting, or otherwise. When the tooth is slid upon the dovetailed
stem, it may be secured in its place by any suitable cement, the heating of
which will permit the withdrawal of the tooth whenever it is necessary.
Figure 1 is an enlarged representation (end view), and Figure 2, a back,
or inside view, of an artificial tooth, constructed agreeably to my improvement,
of porcelain,orothersuitableplastic material, and furnished with the dovetailed
groove a,a. Figure 3 is an end view of another tooth, in which the dovetailed
groove bis formed of thin metal, and inserted in the material of which the
tooth is composed. Figure4is an end view; and Figure 5,a longitudinal edge
view of the metal groove detached; the edges c,c, are turned upward and in-
ward, and jagged, and there are loops d, d, which being imbedded in the
material of the tooth, give it strength and coherence, and unite the tooth and
groove inseparably together. Figures 6 and 7 are end views of teeth, in which
the form of the dovetailed groove is varied,as it may be without prejudice to
my Invention; Figure 8 is a front view of an artificial palate furnished with
tooth plates e,e,un each of which there is a dovetailed stem f, either solid or
hollow,corresponding to the groove a or 6 of the tooth. Teeth of a suitable
character are slid upon the stems f,up against the artificial palate, which forms
a stop orabutment,and supports the tooth when used for mastication &c.,as
is shewn by Figure 1,which is a side or edge section of the palate and tooth.
Figure 9 is a front view of the artificial palate and teeth complete, the teeth
being kept in their places by means of a cement capable of being softened by
heat. The cement commonly used by dentists, and known by the name of
silpher, is well adapted for this purpose. In the event of any tooth of the set
requiring to be removed for repair or otherwise,heat is applied to soften the
cement, when the tooth can be slid down the stem and readily withdrawn
from its place.
What I claim as my Invention, and secured to me by the before-recited

page_text: Letters Patent is, the construction and mode of fixing artificial teeth, as
herein before described, and shewn in the annexed Drawings.
i
In witness whereof, I, the said James Thom, have hereunto set my
hand and seal, this Thirtieth day of July, in the year of our Lord
One thousand eight hundred and fifty-seven.