AN IMPROVEMENT IN THE MANUFACTURE OF ARTIFICIAL TEETH
Year: 1854

page_text: LETTERS PATENT to Mahlon Loomis, of the State of Massachusetts, of the
United States of America, for the Invention of "AN IMPROVEMENT IN
THE MANUFACTURE OF ARTIFICIAL TEETH."
Sealed the 21st July 1854, and dated the 26th May 1854..
PROVISIONAL SPECIFICATION left by the said Mahlon Loomis at the
Office of the Commissioners of Patents, with his Petition, on the 26th
May 1854.
I, MAHLON LOOMIS, of the State of Massachusetts, of the United States of
America, do hereby declare the nature of my Invention of "Au IMPROVEMENT
IN THE MANUFACTURE OF ARTIFICIAL TEETH " to be as follows:-
My Invention consists in making whole sets, or the upper or lower halves,
or parts of sets of artificial teeth, all of porcelain. A half set consists of but
one piece of material, there being no metallic plate, as in the usual
way, but
the same material of which the teeth themselves are made is used instead of a
metallic plate. To make a full set of artificial teeth, thin silver plated or
other proper metal metallic plates are first to be fitted accurately to the upper
and lower jaws, in order that the exact size and shape of that part of the mouth
to be fitted may be definitely known. These plates are to be made by the
ordinary process of making gold plates, to which sets of teeth are usually
fastened. Wax is next to be placed upon these plates, in order to determine
somewhat the length and position of the teeth to be made.
Next the inside of the plate, or that side which is applied to the flesh of the
mouth, is to be filled and covered over with dentists' plaster [wet to a convenient

page_text: consistence], and said plate with the plaster is to be placed upon a thin bed
of the same plaster, so that the plaster on the plate shall rest on the bed of
plaster. To prevent the bed of plaster from spreading, and the better to
shape it, it may be confined by means of a strip of sheet iron about an inch
in width, bent somewhat in the form of the letter U, and continued straight
across, so that the ends may touch each other.
When this bed of plaster has become sufficiently hard or set, the sheet iron
or metallic form last mentioned is to be removed. The metallic plate is next
to be taken off from the whole of the plaster; after this the plaster may be
neatly trimmed. Then this plaster cast, upon which is to be formed the upper
half of the set of teeth, is to be enlarged, to counteract in part the effect of the
shrinkage of the porcelain material consequent upon baking. This may be
effected as follows:-As different mixtures for porcelain vary in the amount
they contract by baking, the extent of enlargement [as near as I can estimate
the enlargement, I should say, generally speaking, it would increase each of the
dimensions of the mould one-sixteenth of it;] must be in the proportion to the
amount of shrinkage, which may be ascertained by measurement and experi-
ment. This ascertained, the aforesaid plaster cast, upon which is to be formed
the half set, or that portion for the upper jaw, may be scooped out sufficiently
to allow for the shrinkage, and it may be extended back or lengthened the
proportional distance from the mark left by the rear edge or limit of the plate,
and so as to allow for the longitudinal shrinkage. When the necessary
enlargement of the plaster cast has been completed, the wax which was before
placed on the metallic plate is to be removed therefrom and placed on the
plaster cast, the deficiency at its two extremities being supplied, if necessary,
and its height and breadth corrected (if requisite) by the addition of other
portions of wax. This wax so put on the cast is designed to form a spaco
between two pieces of plaster, which are to compose the inatrix for forming the
porcelain material for the teeth. After the wax has been thus adjusted it may
be oiled, in order that prepared plaster, which is next to be poured or placed
upon and over both the wax and the remaining surface of the plaster cast, upon
which it is placed, may subsequently be more easily separated from said wax
and plaster, which separation is to be effected when this plaster last used has
become hard or set. This plaster last put in is for the purpose of forming the
other portion of the matrix. Next a sufficient portion of the plaster so removed
inust be cut away from the whole mass, in order to make, when the two parts
of the mould are placed in contact, a space which will admit of the porcelain
mixture running back far enough to form that portion of the upper part of the
-set which is usually made of metallic plate. The space thus made between

page_text: the masses of plaster constitutes the matrix for forming the upper portion of
the set of teeth. That matrix for forming the lower portion of the set of teeth
is to be made in a similar manner. The enlargement may be done by sawing.
the mass of plaster apart crosswise, and next glueing the parts firmly together
with a piece of wood between them, such piece of wood to correspond in thick-
ness with the amount of shrinkage of the porcelain material in a longitudinal
direction. Next the whole may be again cut apart at right angles with the
first separation, and again glued together with a similar strip of wood between
the two halves, such strip allowing for the transverse shrinkage.
Now, the inferior or last made half of each of these matrices may be spaced
off' upon the edge which determines the outer surface of the porcelain material,
and so as to determine the width and positions of the teeth to be made. First,
that for the upper teeth is spaced to suit the occasion; then to space that for
the lower teeth the flat sides of the two may be placed together, and that for the
lower teeth spaced by marking between the spaces of that for the upper teeth,
then after thinly coating with bayberry tallow that surface of the matrix which
is a representation of that part of the mouth to be fitted, it is ready to receive
the porcelain material, which may next be carved or shaped, as may be neces-
sary. This being done, the mass of porcelain material may be warmed until it
melts, the tallow beneath it, so as to admit of its being removed from the
matrix. While in this condition, any desirable shape may be given to its
edges of the part so formed in the matrix, by applying, where desired, a thinly.
diluted portion of the porcelain mixture by means of a small camel's hair
pencil. Next the cast is to be placed on the tile for baking it, in the usual
way as practised in manufacturing porcelain.. After the two portions have
been taken from the furnace the last time, they may be ground on their inside
surfaces where they may need it, in order to make them fit accurately a plaster
bed or perfect representation of that part of the mouth which it is desired to
fit. When the mouth to be fitted with teeth is of such a peculiar shape as
to render it a difficult operation to remove the carved work from the matrix
which faithfully represents it, as is sometimes the case with the upper jaw, the
difficulty may be obviated in the following manner:-After the metallic plate
has been accurately fitted to the mouth, it may be taken and oiled on its inside
surface. Next, with dentists .plaster, moistened to a convenient consistence,
such portions of the oiled surface of the plate may be covered, as shall most
seem to interfere with its direct removal from the hardened mass of plaster
which is afterwards made to fill it; and it is well to divide into small separate
pieces that plaster which is thus first placed in the plate, in order that it may
be subsequently more easily removed from the work which is to be shaped and

page_text: carved upon it. Next, when these plaster pieces have become hard, their outer
surface should be thinly covered with bayberry tallow or its equivalent. The
remaining portion of the oiled surface of the plate is next filled and covered
over with a similar preparation of plaster; when this becomes hard it is also
to be covered with bayberry tallow or the equivalent, and the tallowed surface
placed upon a thin bed of prepared plaster, confined to its place by means of a
sheet iron form, as before spoken of. The plate may next be removed and
the mould enlarged, and finished in the same way as the matrix before
described.
Some of the advantages of making sets of teeth in my way are quite appa-.
rent; for a half set thus, all solid and in one piece of material, will be in
use a cleaner and purer job than those made in the usual way [viz., of gold
metallic plate and teeth fitted thereto], there being no joints around the teeth
made after my plan for the accumulation of foreign substances. They can also
be afforded at an incomparably lower price than those as usually made, thus
extending the benefits of artificial teeth to hundreds of persons who cannot
afford them on gold or platina plates. In actual practice I find it is much
easier to make teeth in this way, my method proving to be a great saving of
time and labor. I do not claim the process above set forth. In making sets
of artificial teeth, I do not claim the spreading of a gum enamel over one side
of a metallic roof plate upon which the teeth are fastened, nor the extension of
the porcelain guin someway and not entirely upon the roof; but what I claim
as my Invention is, the improved manufacture of whole or half sets of porcelain
or mineral teeth, substantially as described.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Mahlon Loomis in the Great Seal Patent Office on the 26th
September 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MAHLON
LOOMIS, of the State of Massachusetts, of the United States of America, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of May, A.D. 1854, in the seven-
teenth year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Mahlon Loomis, Her special license that I, the said
Mahlon Loomis, my executors, administrators, and assigns, or such others as T,
the said Mallon Loomis, my executors, administrators, and assigns, should a
any time agree with, and no others, from time to time and at all times thereafter

page_text: 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 of "A NEW AND USAFUL
IMPROVEMENT IN THE MANUFACTURE OF ARTIFICIAL TEETH," upon the condition
[amongst others] that I, the said Mahlon Loomis, by an instrument in writing
under iny hand and seal, should particularly describe and ascertain the nature
of the said Invention, and in what manner the sanic was to be performed, and
cause the same to be filed in the Great Seal Patent Office, or Office of Iler
Majesty's Commissioners of Patents, within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Mahlon Loomis, do hereby declare tho
nature of my said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following Specification,
and the accompanying Drawing, letters, figures, and references thereof:-
Of the said Drawing, Figure 1 represents a perspective view of my improved
upper jaw half sets of teeth. Figure 2 is a perspective view of the lower jaw
half sets of the kind. Figures 3 and 4 are longitudinal sections of such half
sets. Figure 5 is a top view of the half mould of the upper jaw, the same
exhibiting, by the colored portion a, the amount of enlargement for shrinkage
of the porcelain, as herein-after described. Figure 6 is a similar view of the
lower part of the mould for the lower jaw set, and shows the process of
enlargement for such purpose, it being effected by sawing the mould longitudi-
nally and transversely into four pieces b, c, d, e, and extending them apart and
inserting strips of wood f, g, between them.
My Invention consists in making whole sets, or the upper or lower halves or
parts of sets of artificial teeth, all of porcelain.
A half set consists of but one piece of material, there being no metallic
plate as in the usual way; but the same material of which the teeth them:-
selves are made is used instead of a metallic plate.
To make a full set of artificial teeth, thin silver plated or other proper
metallic plates are first to be accurately fitted to the upper and lower jaws, in
order that the exact size and shape of that part of the mouth to be fitted may
be definitely known. These plates are to be made by the ordinary process of
gold plates, to which sets of teeth are usually fastened. Wax is next to be
placed upon these plates, in order to determine somewhat the length and
position of the teeth to be made. Next, the inside of the plate, or that sido
which is applied to the flesh of the mouth, is to be fitted and covered over with
dentists plaster [wet to a convenient consistence], and said plate with the
plaster is to be placed upon a thin bed of the same plaster, so that the plaster

page_text: on the plate shall rest on the bed of plaster. To prevent the bed of plaster
from spreading and the better to shape it, it may be confined by means of a
strip of sheet iron about an inch in width, bent somewhat in the form of the
letter U, and continued straight across, so that the ends may touch each
other.
When this bed of plaster has become sufficiently hardened, the sheet iron or
metallic form last mentioned is to be removed. The metallic plate is next to
be taken off from the whole of the plaster; the plaster after this may be
neatly trimmed. When this plaster cast, upon which is to be formed the upper
half of the set of teeth, is to be enlarged, to counteract in part the effect of the
shrinkage of the porcelain material consequent upon baking, such may be,
effected as follows:-As different mixtures for porcelain differ in the amount
they contract by baking, the extent of enlargement [as near as I'
can estimate
this enlargement, I should say, that, generally speaking, it would increase the
dimensions of the mould one-sixteenth of it,] must be in proportion to the
amount of shrinkage, which may be ascertained by measurement and experi-
ment.
This ascertained, the aforesaid plaster cast, upon which is to be formed the
half set, or that portion of the upper jaw, may be scooped out sufficiently to
allow for shrinkage, and it may be extended back or lengthened the propor-
tional distance from the mark left by the rear edge or limit of the plate, and
so as to allow for the longitudinal shrinkage. When the enlargement of
the plaster cast has been completed, the wax which was before placed on the
metallic plate is to be removed therefrom and placed on the plaster cast, tho
deficiency at its two extremities, being supplied, if necessary, its height and
breadth corrected [if requisite] by the addition of other portions of wax. This
wax so put on the cast is designed to form a space between the two pieces of
plaster which are to compose the matrix for forming the porcelain material of
the teeth.
After the wax has been thus adjusted it may be oiled, in order that pre-
pared plaster, which is next to be poured or placed upon and over both the wax
and remaining surface of the plaster cast upon which it is placed, may be sub-
sequently the more easily separated from said wax and plaster, which sepa-
ration is to be effected when this plaster last used has become hard or set.
This plaster last put on is for the purpose of forming the other portion of the
matrix. Next, a sufficient portion of the plaster so removed must be cut away
from the whole mass, in order to make, when the two parts of the mould are
placed in contact, a space which will admit of the porcelain mixture running
back far enough to form that portion of the upper- part of the set which is

page_text: usually made of metallic plate. The space thus made between the masses of
plaster constitutes the matrix for forming the upper portions of the set of
teeth.
That matrix for forming the lower portion of the set of teeth is to be made in
a similar manner. The enlargement may be done by sawing the mass of plaster
apart crosswise, and next glueing the parts firmly together with a piece of wood
between them, such piece of wood to correspond in thickness with the amount
of shrinkage of the porcelain material in a longitudinal direction. Next, the
whole may again cut apart at right angles with the first separation, and
again glued together with a similar strip of wood between the two halves, such
strip allowing for the transverse shrinkage.
Now the inferior or last made half of each of these matrices may be spaced off
upon the edge which determines the outer surface of the porcelain material,
and so as to determine the width and position of the teeth to be made. First,
that for the upper teeth is spaced off to suit the occasion; then to space that
for the lower teeth, the flat sides of the two may be placed together, and that
for the lower teeth spaced by marking between the spaces of that for the upper
teeth; then, after, thinly coating with bayberry tallow that surface of the.
matrix which is a representation of the part of the mouth to be fitted, it is
ready to receive the porcelain material, which may next be carved or shaped as
may be necessary. This being done, the mass of porcelain may be warmed
until it melts the tallow beneath, so as to admit of its being removed from the
matrix.
While in this condition, any desirable shape may be given to its edges of
the part so formed in the matrix by applying, where desired, a thinly diluted
portion of the porcelain mixtures by means of a small camel's hair pencil.
Next, the cast is to be placed on the tile for baking it, in the usual way as
practised in manufacturing porcelain. After the two portions have been taken
from the furnace the last time, they may be ground on their inside surfaces
where they may need it, in order to make them fit accurately a plaster bed or
perfect representation of that part of the mouth which it is desired to fit.
When the mouth to be fitted with teeth is of such a peculiar shape as to render
it a difficult operation to remove the carved work from the matrix which faith-
fully represents it, as is sometimes the case with the upper jaw, the difficulty
may be obviated in the following manner :-After the metallic plate has been
accurately fitted to the mouth, it may be taken out and oiled on its inside sur-
face. Next, with dentists plaster, moistened to a convenient consistence, such
portions of the oiled surface of the plate may be covered as shall most seem
to interfere with its direct removal from the hardened mass of plaster, which

page_text: is afterwards made to fill it; and it is well to divide into small separate pieces
that plaster which is thus first placed in the plate, in order that it may be
subsequently more easily removed from the work which is to be shaped and
carved upon it. Next, when these plaster pieces have become hard, their outer
surface should be thinly covered with bayberry tallow or its equivalent. The
remaining portion of the oiled surface of the plate is next filled and covered
over with a similar preparation of plaster. When this becomes hard it is also
to be covered with bayberry tallow or the equivalent, and the tallowed surface
placed upon a thin bed of prepared plaster, confined to its place by means of
a sheet iron form, as before spoken of. The plate may next be removed
and the mould enlarged, and finished in the same way as the matrix before
described.
Some of the advantages of making sets of teeth in my way are quite apparent;
for a half set thus, all solid and in one piece of material, will be in use a cleaner
and purer job than those made in the usual way [viz., of gold metallic plate
and teeth fitted thereto], there being no joints around the teeth made after my
plan for the accumulation of foreign substances. They can also be afforded
at an incomparably lower price than those as usually made, thus extending
the benefits of artificial teeth to hundreds of persons who cannot afford them
on gold or platina plates. In actual practice I find it is much easier to make
teeth in this way, my method proving to be a great saving of time and labor.
I have fitted several jaws, both upper and lower, with sets of teeth made on my
improved plan, which teeth are now in daily use, answering every requirement.
I do not claim the process above set forth. In making sets of artificial
teeth, I do not claim the spreading of a gum enamel over one side of a
metallic roof plate upon which the teeth are fastened, nor the extension of the
porcelain gum some way and not entirely upon the roof; but what I claim as
my Invention is, the improved manufacture of whole or half sets of porcelain
or mineral teeth, substantially as described.
In testimony whereof, I have hereunto set my hand and seal, this Twenty-
second day of June AD 1854