IMPROVEMENTS IN SECURING ARTIFICIAL TEETH IN THE MOUTH
Year: 1865

page_text: LETTERS PATENT to George Ash, of Great Marlborough Street, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN SECURING
ARTIFICIAL TEETH IN THE MOUTH."
Sealed the 8th May 1866, and dated the 2nd December 1865.
PROVISIONAL SPECIFICATION left by the said George Ash at the
Office of the Commissioners of Patents, with his Petition, on the 2nd
December 1865.
I, GEORGE ASH, of Great Marlborough Street, in the County of Middlesex,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
SECURING ARTIFICIAL TEETH IN THE MOUTH," to be as follows:-
This Invention has for its object improvements in securing artificial teeth
in the mouth. Artificial teeth are at the present time usually mounted on a
base or plate of vulcanite, gold, or other material made accurately to fit the
gums and interior of the mouth, and to secure such base or plate within the
mouth springs or clips are ordinarily employed.
According to my Invention I secure the base or plate, more solidly by so
arranging it that a vacuum may be formed and maintained between it and the
interior of the mouth. For this purpose I form a hole through or cavity in.
the base or plate, and fit into this hole or cavity a diaphragm either elastic in
itself or else supported by a spring, which tends to press it away from or out
of contact with the palate or gum. In fastening the teeth in the mouth the
finger is pressed on this diaphragm, or the diaphragm is otherwise depressed,

page_text: and the air is thus expelled from beneath it. On the finger being removed
the spring presses up the diaphragm, and so a partial vacuum is formed
beneath the base or plate, which is thus caused to adhere with sufficient force.
This arrangement alone would not however be efficient, as the joint between
the diaphragm and the palate or gums would not remain air-tight. In order
to ensure an air-tight joint with the palate or gum around the diaphragm a
piece of leather or other similar material is secured to the under side of the
base or plate around the diaphragm, and its edges which should be left loose
rest on the palate or gum, and when the partial vacuum is formed beneath
the leather it adheres closely and makes a perfect joint.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Ash in the Great Seal Patent Office on the
2nd June 1866,
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
ASH, of Great Marlborough Street, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of December, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-ninth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said George Ash, Her special licence that I, the said George Ash, my
executors, administrators, and assigns, or such others as I, the said George
Ash, 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 SECURING
ARTIFICIAL TEETH IN THE MOUTH," upon the condition (amongst others) that I,
the said George Ash, my executors or administrators, 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 George Ash, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-

page_text: formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:
This Invention has for its object improvements in securing artificial teethi
in the mouth. Artificial teeth are at the present time usually mounted on a
base or plate of vulcanite, gold, or other material made accurately to fit the
gums and interior of the mouth, and to secure such base or plate within the
mouth springs or clips are ordinarily employed.
According to my Invention I secure the base or plate more solidly by so
arranging it that a vacuum or partial vacuum may be formed and maintained
between it and the interior of the mouth. For this purpose I form a hole through
a cavity in the base or plate, and fit into this hole or cavity a diaphragm either
elastic in itself, or else supported by a spring, which tends to press it away
from or out of contact with the palate or gum. In fastening the teeth in the
mouth the finger is pressed on this diaphragm (or the diaphragm is otherwise
depressed), and the air is thus expelled from beneath it. On the finger being
removed the spring presses up the diaphragm, and so a partial vacuum is
formed beneath the base or plate, which is thus caused to adhere with suffi-
cient force by the pressure of the atmosphere. In order to make. this
arrangement,more efficient, and in order to ensure an air-tight joint with the
palate or gum around. the diaphragm a piece of thin gutta percha, india-
rubber, leather, or other similar material is secured to the under side of the
base or plate around the diaphragm, and its edges which should be left loose
rest on the palate or gum, and when the partial vacuum is formed beneath
the leather it adheres closely, and makes a perfect joint.
In the annexed Drawing Figure 1 shows a plan of a set of artificial teeth
mounted in vulcanite or hardened india-rubber, and suitable for the upper jaw,
and I would remark that it is to sets of teeth adapted to the upper jaw that my
Invention is more especially applicable; Figure 2 is a section taken at the
line 1, 1, Figure 1; Figure 3 shows some of the parts on a larger scale.
a, a, are the teeth with a setting of vulcanite formed around them in the
usual way; c, c, is a metal ring of U-form in section, which is embedded in
the vulcanite composition when in a plastic state, and which when the vulcanite
is hardened becomes secured in its place; d, d, is a flexible diaphragm of
vulcanized india-rubber cut to form and sprung into the ring c as is shown;
e, e, is a flap or apron of thin gutta percha, leather, or other material secured
around the diaphragm d to make a perfectly tight joint against the palate or
gum of the wearer. It will be seen that the material of which the flap e is
formed is lapped over the flexible diaphragm d, the elasticity of which causes
it to be forced into the cavity of the ring c all round, and the flap is thus

page_text: securely held. Where a gold plate is employed in place of a vulcanite setting
for the teeth I proceed in a similar manner, except that the U-groove of the
ring c is formed with the plate. In some cases where the teeth are set in a
base of vulcanite in place of moulding a ring c therein as before described to
receive a separate flexible diaphragm, I make the flexible diaphragm in one
pięce with the vulcanite. On the model of the mouth on which the form
for the vulcanite is moulded in wax I produce a small eminence corresponding
with the cavity which it is desired there should be under the flexible
diaphragm. I then, as is usual, make a mould from the model, and the
vulcanite composition is pressed into the mould around the teeth. so as to
make a firm setting for them, but for the part where the diaphragm is to
be formed, and for a distance around it I employ in place of hard vulcanite
composition a composition containing less sulphur, and known to dentists
as "soft rubber," which composition when exposed to the heat-necessary to
produce the vulcanite, does not become hard, but retains more or less the
nature of ordinary vulcanised india-rubber.
Figure 4 shows a plan of a set of teeth in which this method of construction
is adopted.
ta, a, are the teeth; b, b, the vulcanite in which they are set; c, c, the parts,
which are made of soft rubber. It will be seen that this soft rubber is con-
tinued at cas far back over the palate as it can conveniently be in order to
secure an air-tight fit.
In witness whereof, I, the said George Ash, have hereunto set my hand
and seal, this Second day of June, in the year of our Lord One
thousand eight hundred and sixty-six.
GEORGE ASH Gal