IMPROVEMENTS IN SETTING ARTIFICIAL TEETH
Year: 1859

page_text: LETTERS PATENT to John Macintosh, of 40, North Bank, Regent's Park,
in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
SETTING ARTIFICIAL TEETH."
Sealed the 4th May 1860, and dated the 8th December 1859.
PROVISIONAL SPECIFICATION left by the said John Macintosh at the
Office of the Commissioners of Patents, with his Petition, on the 8th
December 1859.
I, JOHN MACINTOSH, of 40, North Bank, Regent's Park, in the County of
Middlesex, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN SETTING ARTIFICIAL TEETH," to be as follows:-
This Invention has for its object improvements in setting artificial teeth. For
this purpose I employ collodion (or a solution of gun cotton or fibre in a solvent);
this material I apply to the teeth to be set when in a fluid or soft state, so
that when it hardens, the teeth may become securely imbedded in it. A form
or mould is by preference employed to bring the mass of collodion in which
the teeth are set to the proper shape to fit the mouth. Cotton or other fibre
may be embedded in the collodion to increase its toughness, and the outer
surface or the whole of the collodion may be colored to look like the natural
gum.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed.
by the said John Macintosh in the Great Seal Patent Office on the
8th June 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
MACINTOSH, of 40, North Bank, Regent's Park, in the County of Middlesex,
send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of December, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of
Her reign, did for Herself, Her heirs and successors, give and grant unto
me, the said John Macintosh, Her special licence that I, the said
John Macintosh, my executors, administrators, and assigns, or such others
as I, the said John Macintosh, 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 "IM-
PROVEMENTS IN SETTING ARTIFICIAL TEETH," upon the condition (amongst others)
that I, the said John Macintosh, 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 Inven-
tion, 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 John Macintosh, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, 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 setting artificial teeth,
and consists in employing for this purpose the preparation known by the
name of collodion, which is a solution of gun cotton or fibre in a solvent. S
The following is the manner in which I prefer to proceed :-I obtain in the
usual manner an impression in wax of the form of the jaw of the person for
whom the set of artificial teeth is to be made, and from this I make a mould
in plaster, as is well understood. Into this mould I again cast plaster, and so
obtain in plaster a copy of the original wax impression of the jaw. On to this
form I build up in wax or other material a thickness equal to that of the
collodion setting which it is desired to produce, and the teeth to be set are
embedded in the wax in the same manner as they are to be in the collodion
setting; when this is produced on the wax model, and while it is still on the
form, it is oiled all over and a plaster cast is taken of it; this when set is
removed from the form, and the teeth will be found firmly embedded in it, the
whole of the wax is then carefully removed. Thus two plaster forms are
obtained, which, when put together, form a mould, and enclose between them
a space corresponding in form with the collodion setting to be produced;

page_text: these forms are placed in a metal box, such as is used in the vulcanite process,
which is well understood by dentists, and they are secured the one in the top
and the other in the bottom of the box by running them in with plaster. The
collodion to be employed may be prepared in the ordinary manner; and I
prefer in order to increase its toughness to mix with it a small quantity of
short cotton fibre, and I evaporate the solvent until the collodion is brought to
a plastic and putty like state. If it be desired to obtain a hard setting, I add
to the collodion and thoroughly incorporate with it powdered gum copal, in
quantity varying according to the hardness desired; if great hardness is
required I employ as much as 20 per cent. The collodion whilst still warm I
carefully press into the mould around the teeth, as in filling a mould with the
compound of india-rubber and sulphur in making teeth of vulcanite, as is well
understood; I then place the two parts of the mould together, and force
them together by means of the screw with which the box containing them is
fitted; thus the collodion between the two parts of the mould is forced into
every crevice of it; and in order that the collodion may remain thoroughly
plastic the mould is kept heated to about 200° Fahrenheit; when the two
parts of the mould are pressed close together, the mould is allowed to cool,
and when cold, the teeth with the setting, which is then complete, are removed.
If it is necessary in order to render the fit of the setting more complete, parts
of it may afterwards be pared away as has before been practised when settings
of other material have been employed. In order that the teeth may be
securely held by the setting, they may be notched or under-cut in a similar
manner to the teeth now employed for setting in vulcanite; and I prefer to
form the teeth with a hole or passage up the centre of each, which at the base
is opened out as wide as the tooth will admit of without becoming unduly
weakened. These holes or passages I fill with collodion, singly or in the
process of filling the mould, so that when the setting is finished each tooth will
have a stem of collodion forming part of the setting passing up its centre, and
the teeth thus become firmly beld, or they may be attached to the setting by
pins, as is well understood. I color the collodion to make it resemble the
natural gum by means of alkanet root, the whole of the collodion may be thus
colored while in a liquid state; or the setting, when finished, may have a
coating of colored collodion applied to its surface. If it be desired to obtain
a plate or thin flexible setting, I proceed in a similar manner to that already
described, but I produce the two forms of which the mould consists in a
readily fusible metal (a mixture of tin and lead answers well) in place of in
plaster as before described; but in this case, after producing the wax model
the teeth are not left in it whilst the plaster cast is taken, but are first carefully

page_text: removed. The collodion is formed into a sheet of the desired thickness, and
there is cut out from this sheet, with the assistance of a template previously
prepared by measuring from the mould, a piece of suitable form to produce
the setting. I then lay the piece of sheet collodion, previously rendered plastic
by heat, in its place in one half of the mould, and the other half is then put
over the first and pressed firmly down upon it by the use of a screw box, as
before explained. The mould is heated to about 200° Fahrenheit, so as to
keep the collodion perfectly plastic, and the pressure applied is sufficient to
force the collodion into every crevice of the mould. When the mould is cold
and the collodion is set, the collodion plate is removed. The teeth are after-
wards fitted in their places in their places on the plate, and are fixed either by
metal pins, or as is preferred, the teeth are, as before mentioned, made with a
passage up the centre, which is filled with collodion, and afterwards the
collodion in the tooth and the plate at the part where the tooth is to be fixed
are both moistened with ether, and they are pressed in contact till the solvent
evaporates, when they will be found firmly attached the one to the other.
Collodion may also be employed for setting in the same manner as sea-horse
tooth is employed, and as is well understood by dentists. In this case a block of
collodion (mixed with fibre and copal if considered desirable) is formed and
afterwards carved out to the form desired, the teeth being fitted and fixed as
when sea-horse tooth is employed.
Collodion, as a setting of teeth, has this advantage over many of the substances
heretofore employed, that it does not decompose and become foetid in the
course of long exposure in the mouth; it is also free from the metallic taste
which all metal has more or less; it is not liable to lacerate the gums, and is
not easily detected when in use.
In witness whereof, I, the said John Macintosh, have hereunto set my
hand and seal, this Eighth day of June, in the year of our Lord
One thousand eight hundred and sixty.
JOHN MACINTOSH. (L.S.)