IMPROVEMENTS IN DENTISTRY
Year: 1883

page_text: LETTERS PATENT to Sydney Pitt of Sutton in the County of Surrey for an
Invention of "IMPROVEMENTS IN DENTISTRY Communicated to him from
abroad by Cassius Montezuma Richmond of New York United States of
America
COMPLETE SPECIFICATION filed by the said Sydney Pitt at the Office of
the Commissioners of Patents on the 22nd May 1883.
SYDNEY PITT of Sutton in the County of Surrey.
DENTISTRY" Communicated to me from abroad by Cassius Montezuma Richmond
of New York United States of America.
"IMPROVEMENTS IN
This invention relates to a new system of dentistry by which sets of artificial
teeth may be readily and firmly applied to roots existing in a mouth and to a new
method of preparing such roots.
.
It is described to me by my foreign correspondent as follows:-
In applying artificial teeth it has heretofore been customary to make plates upon
which said teeth were attached; which plates extended over the roof of the mouth
or were located in the lower jaw. By these improvements the use of plates is
entirely avoided. In order that the tooth be properly applied it is important that
the root be first prepared.
:.
In the application of artificial dentures it is often necessary that the part of the
tooth which projects beyond the gum, or that portion which is known as the crown
should be removed in such a way that the root may serve as a support for the
artificial dentures. The said artificial denture is supported upon a cap surrounding
the root and enclosing it below and to a certain extent beneath the gum.
My present improvement has especial reference to a method of preparing the
roots for the application of such cap, but it is equally applicable to the preparation
of roots for any other suitable support for artificial dentures. The present method
is particularly applicable to single root teeth and it enables the operator not only
to externally prepare the root for the reception of the holding device, but to also so
treat the root as to entirely prevent or greatly lessen any danger of subsequent
irritation which might otherwise. produce abscesses or similar disorders. I have
L

page_text: discovered that by the method which I shall hereafter describe, the tooth crown
can be removed, in many cases painlessly, and in those cases in which some pain
might be felt I propose to use a method of freezing the teeth, which also forms part
of my present improvement. In carrying out my method practically I first cut
horizontal grooves through the enamel of a tooth opposite each other, one on the
face of the tooth next to the gum, and the other on the palatine wall of the tooth.
These grooves are preferably cut by means of a rapidly revolving corundum dental
disc or wheel, but I do not limit myself to this method.
These grooves prevent the splitting of the crown in the subsequent operation
and likewise afford a guide for the cutting tool. I thereafter apply the cutting
edges of a pair of excising forceps to the grooves already cut and quickly sever the
crown from the root leaving the nerve bare. In some instances the nerve follows
the crown on its removal. This operation seems to paralyze the pulp or nerve,
driving the blood therefrom and benumbing it. I then provide a suitably shaped
piece of wood which should be cut to correspond generally to the shape of the nerve
cavity or pulp canal. This wood should be of a soft and easily compressible nature.
I find the so called orange wood well adapted to this purpose. The wood so shaped
I drive at a single blow to the apex of the root, severing the pulp at its foraminal
constriction, and in many instances forcing it out of its cavity toward the mouth
by displacing it. I then remove the wood and carefully cleanse the pulp canal
with cotton saturated with carbolic acid or other antiseptic, removing if necessary
any particles remaining of the pulp, by means of a dental broach..
In order to avoid pain by treating the tooth while still benumbed and to prevent
abscess or inflammation it is very important to close the pulp canal immediately.
This I accomplish by driving a second piece of wood shaped like the first into the
pulp canal in the presence of carbolic acid filling it to its apical foramen thus
perfectly excluding the air. When the pulp canal is so small that I cannot force a
sharpened piece of wood into it, or when the pulp has become partially calcified
and is still sensitive, or when there is a deposit of sensitive secondary dentine
precluding the excavation for the insertion of a pivot and a proper plugging of the
end of the root, "I then adopt a freezing process using a suitable spray apparatus
and freezing the tooth and pulp immediately after cutting the grooves for breaking
off the tooth. I can then drill out what remains of the partially calcified nerve or
pulp without causing pain and I then proceed to plug the teeth according to the
method herein before described. In practice for the reception of my artificial
denture to which I have previously referred, I generally drill out the lower portion
of the tooth making a cylindrical cavity larger than the nerve canal, my invention
will be readily understood by the accompanying Drawings, in which similar letters
refer to similar parts.
Figure I represents an elevation of the crown and root showing the corundum
disc in process of grooving the same.-Figure 2 shews the forceps in position before
the crown is removed. Figure 3 shews the operation of driving out the pulp, and
Figure 4 shows the prepared root. Similar letters refer to similar parts.
A represents the root, and B the crown before removal Crepresents the grooves,
and D the corundum disc, E represents the suitably prepared piece of wood for
driving out the nerve, and G represents the nerve or pulp driven out.. H represents
the subsequent wood filler filling the upper part of the nerve cavity; and J
represents the lower portion of the root suitably drilled for the pin or other
attaching contrivance."
:
In Figure 1 is shown the operation of grooving the tooth between the root
One groove has already been cut, and the disc is shown cutting the
and crown.
other.
In Figure
the grooves having been cut the forceps are shewn as.applied. By
these forceps the crown is removed, and a suitably shaped piece of wood having
'been prepared it is shown in Figure 3, as driven up to the apical foramen of the
root. This operation expels the nerve pulp. Thereafter the permanent wood filler
is driven into the nerve cavity, as shown in Figure 4, and if desired the lower

page_text: part of the pulp cavity is enlarged for the purpose of receiving some attaching
contrivance. Whether or not the tooth is to be frozen depends upon its character;
and in general I do not recommend this process. There are however certain
peculiar cases where it is necessary.
In carrying out the preceding operation in order that pain may be avoided I.
sometimes use this invention. The object of this invention is to operate without
pain to the patient, upon the roots of teeth, specially upon those which are to be
used as supports for artificial dentures, and my invention consists in a freezing
process applied to the roots as hereinafter described.
In order to secure proper supports for the artificial dentures before referred to, it
is often necessary to remove the crown from a tooth in which the nerve is still alive,
or to cut down a root to a level with the gum-an operation which by ordinary'
modes of treatment is exceedingly painful. I effect such operation without pain by
subjecting the teeth to a freezing process similar to that used in freezing gums.
I first isolate the tooth to be operated upon by a rubber dam, so that injury to
adjacent teeth by freezing the same is prevented. I then throw a jet or spray
of ether or other volatile liquid directly upon the tooth until the nerve therein is
frozen.
The tooth may then cut or drilled, the nerve extracted, and such other operations
as are requisite be performed without pain to the patient.
The root may be then plugged in any desired manner. In some instances where
it is necessary to operate upon a tooth without removing the crown, the same mode
of treatment may be employed-the nerve being frozen and then extracted.
I am aware of the use of a spray of volatile liquid for the purpose of benumbing
the flesh prior to operating directly upon the same, but I am not aware that the
process of freezing has ever been employed to benumb a nerve enclosed within a
tooth and to which access cannot be directly had, by freezing the tooth and
thereby preventing the pain that would otherwise result in gaining access to
the nerve.
The roots having been properly prepared, I then proceed to apply artificial
dentures to them as follows. Figure 5 represents a view of the root with the tooth
crown applied. Figure 6 a sectional view of the same Figure 7 a section of the
prepared root with the ferrule in situation Figure 8 a view of the prepared root
with the crown in situation, being there held by wax. Figure 9, a view of the
incomplete crown shown in Figure 8 when removed from the tooth.-Figure 10 a
view of the same with the attaching pin in position ready to be invested.
Figures 11 and 12 represent views of a modified ferrule.
A represents the root. In practice a hole J is drilled in the same as shown.
The end of the tooth being then properly prepared, a ferrule B is made of such a
size as to exactly fit the base of the root. This ferrule is shewn in position in
Figure 7. A suitable crown C is then selected to be applied to the root. Of course
color size and shape should be consulted in this selection. Upon the back of this
crown is placed a protecting platinum or gold plate D which has holes through it
to allow of the passage of the pins E which are firmly embedded in the porcelain
in the well known manner. The root and crown having been so prepared, the
crown is placed in position and attached to the ferrule by wax G as shewn in
Figure 8. This wax will hold the crown sufficiently firmly in position to allow of
the removal of the ferrule B. In Figure 9 the ferrule B and the crown attached
thereto by wax are clearly shown. Thereafter a suitable pin is imbedded in the
wax as shown in Figure 10. This pin is designed to enter the hole J drilled in the
root. The prepared crown shown in Figure 10 is then invested or protected by a
suitable covering of marble dust and plaster leaving the wax portion G exposed.
This investiture will hold the parts firmly in the position which they are to occupy
when placed in the mouth. The wax may then be readily melted from behind the
crown and replaced by a suitable gold solder which may be blown in by a blow
pipe and fused around the pin M. This solder will unite with the pin, the ferrule B
the plate D and pin Z making a solid metal backing to the crown C and firmly
.

page_text: holding all the parts together The prepared crown is then slipped upon the
prepared root as shown in Figure 6 and cemented thereto. The said ferrule when in
position should project under the free margin of the gum sufficiently to protect the
root from decay. That part of said ferrule is likewise concealed from view by the
gum; The cement surrounding the pin F is shown at J.
In Figure 11 is shown a ferrule in position similar to the one shown in Figure 6,
the difference being that in this case the ferrule is made in the form of a cup
surrounding the end of the root with a hole pierced therethrough.
In Figure 12 the separate ferrule is shewn, the method of attaching is the same.
I do not limit myself to a crown prepared by the exact process here described,
as said crown might be prepared in other ways, but I prefer the process here
described.
It will be seen that when this denture is,applied to a root, the end of the root is
entirely protected from the injurious action of the fluids of the mouth and is
hermetically sealed, being covered by a closed cap, This enclosing cap is of the
greatest importance, because otherwise decay must necessarily take place by reason
of the action of the fluids of the mouth on the exposed dentine and the dentine
would become useless. By this arrangement therefore both the end of the root and
so much of the same as might otherwise be exposed to the fluids of the mouth are
hermetically sealed being covered by a closed cap. This enclosing cap is of the
greatest importance because otherwise decay must necessarily take place by reason
of the action of the fluids of the mouth on the exposed dentine and the denture
would become useless. By this arrangement therefore both the end of the root and
so much of the same as might otherwise be exposed to the fluids of the mouth are
hermetically sealed, and the root is thus protected from the injurious effect which
would otherwise result from the action of the fluids. It is obvious likewise, that
by this arrangement the end of the root may retain its natural configuration, and
its substance is not destroyed by cutting away or shaping the same at the sides,"
which is very injurious and tends greatly to the destruction of the root. It is
obvious that this part of my invention, namely the sealing cap on the end of the
root may be used with other kinds of dentures and other arrangements of artificial
crowns beside those shown herein, and that when properly applied the root is
completely protected. As shown in Figures 6. 8 and 11, the band or ferrule should
project beneath the gum, and allow the gum to extend to the porcelain crown. The
freedom of the gum from permanent attachment with the end of the root allows
this band to be placed in position without causing irritation.
I do not limit myself to the precise method of attaching this enclosing cap to
the root as other methods might be employed, but the one here shown is the
simplest known to me.
Another way of applying a crown permanently to a root is by the following
method which will be readily understood from the accompanying Drawings in which
Figure 13 represents an elevation, and Figure 14 a section of the root ferrule and
tooth crown.
A represents a prepared root. The lower part of said root should be shaped and
prepared as previously described by me, and the ferrule B should be properly fitted
and applied thereto. The front of this ferrule should be beveled as shown in
Figure 1. The crown C is then prepared as follows, a backing D of metal, such
as platinum is fitted to the back of the crown allowing the pins E to project
*through it. Upon the back of this a layer of gold solder is placed. Said surface
is shown at F. This solder will surround the heads of the pins E and secure the
backing D firmly against the tooth crown C. The crown is then firmly soldered
by the backing plate D against the ferrule B, all said work being done of course
outside of the mouth. The artificial tooth crown may then be put in position on
the root, and the space between the root and the solder F be filled with some
plastic material or gold in the ordinary way. A pin may be first inserted into the
prepared hole in the root and the gold or plastic material packed around said pin

page_text: thereby insuring a firmer hold, or said hole may be otherwise filled..—When I
desire to make my single crown attachable I proceed as follows:-
This improvement consists in a method of attaching artificial dentures by which
they may be readily removed from the mouth, By the processes of fixing said
dentures to roots which I have previously described; after the denture is fixed it
has been impossible to remove it without cutting away the attachment between it
and the root. By my present improvement however the artificial dentures may be
quickly removed from their supports by removing an attaching screw without
exposing the prepared root to injury from the fluids of the mouth.
In the preparation of such roots it is very important that they should be thoroughly
protected from the fluids of the mouth as otherwise they rapidly decay, and it is
therefore necessary that they be hermetically sealed or enclosed in a cap or terminal
and enclosing covering.
By my improvement I attach such cup or covering to the roots and I then attach
the denture to said cup or covering by, some removeable contrivance, the cup or
covering remaining permanently upon the root, while the denture may be removed
without disturbing such cup.
My invention will be readily understood from the accompanying Drawings.
Figure 15 represents a prepared root Figure 16 a cap to enclose the same.
Figure 17 a denture to be applied to, the cap; and Figure 18 an attaching screw
to attach the denture and cap together. Figure 19 a larger view of the
denture showing the structure of the screw thread.. Figure 20 a view of my
denture applied. Figure 21 a view of my denture applied with an artificial
porcelain tooth crown.
"
-
a represents the root. This should be prepared by closing the nerve cavity and
drilling in the manner fully described by me. A suitable recess should be made
in its end to receive a. threaded tube attached to the enclosing cup. c represents.
such cup which has within it and passing upward centrally a threaded tube,
preferably threaded both inside and out, for the reception of the screw g. This
tube should be preferably closed at its upper end. The cup it will be understood'
is made to fit the periphery of the root exactly and to project partly under the
free margin of the gum and is the best form known to me although such projection
is not in all cases absolutely necessary. The cup c. provided with the threaded
tube d. is put in position by means of cement b upon the end of the root and
remains there permanently. A previously prepared artificial denture F is then!
placed upon the enclosing cup. This denture or artificial tooth crown' must fit
accurately the permanent cup so as to prevent the injurious effect of the'
introduction of any food particles or fluids within it. The upper edges both of
the cup e and of the tooth crown F are beveled and cut away fine so as to
interfere as little as possible with the over-lapping gum. A screw g passes through
the artificial tooth crown and into the threaded tube d. and thereby holds the
crown firmly in position. Instead of making the artificial crown of gold it may
have attached to it an artificial porcelain or other crown as shown at H in
Figure 21 the other arrangements being the same. Of course other modes of
attachment beside the screw g could be employed. I usually fill the cavity in the
denture f. Figure 20 with cement so as to form a backing for it.
Another way of attaching such single teeth, and also attaching bridge work is
shown in Drawings 22. 23. 24. 25. 26 and 27. In these Drawings Figure 22
represents in section a root prepared for the attachment of the denture Figure 23,
a cap for covering the root. Figure 24 a section through the portion of the
denture which is to be clamped directly to the root. Figure 25, a securing bolt or
screw. Figure 26 a section showing the denture attached and Figure 27. a view
illustrating the position of a denture comprising several teeth and secured within
the mouth.
The invention consists first in providing the tooth or root, with a metallic or
other suitable attachment permanently secured thereto, and secondly in the use of

page_text: a connecting device, whereby the denture is firmly but removeably connected to
said attachment.
Different means and devices may be used in effecting such connection, the
attachment for instance may be a block of metal inserted in a hollow or
socket of the tooth, and provided with a screw pin to which the denture may
be connected, I prefer however the mode of connection which I will now
describe.
43
When the denture is to be connected to a root the end of the latter is prepared
so as to present a flat face x. and a socket y. and the nerve cavity is filled suitably
to prevent subsequent inflammation.
I then prepare a metal cap A, fitted to cover the end of the root, and if desired
with a flange a. to enclose the root and extend between the latter and the gum, so
as to prevent the fluids of the mouth from reaching the nerve cavity, or coming in
contact with the root.
A projection e within the cap A is threaded internally and is adapted to enter
the socket y, the attachment being secured to the root by cement, which fills the
cavity between the projection and the walls of the socket, as shown in Figure 5.
The denture consists of the metallic portion D and the porcelain teeth E, suitably
secured thereto.
In the metallic portion at the point where the latter is opposite the threaded
opening in the projection e. is an opening i. adapted to receive a screw 8. having an
enlarged head, which screw when passed through said opening and into the
threaded socket, clamps the denture firmly against the face of the attachment A
and holds the denture securely in place, the friction between the conical head of
the screw and the socket, preventing the screw from turning.
-
While the attachment thus effected prevents any movement of the denture, it
permits the ready removal thereof at any time, by the simple.withdrawal of the
screw.
When a pin projects downward from the attachment A, into a socket in the
denture, a transverse screw or key may be used as the securing device.
When the denture comprises a series of teeth it may be secured at one point to
a root t Figure 27, and may at another point be provided with a cap or cup u,
adapted to cover the crown of the tooth t', with which a firm connection may be
made by means of a pin d. It will be seen that the end of the root is covered or
protected so that the fluids of the mouth cannot get access thereto, and that
when the cup A is applied such protection is afforded even when the denture is
detached.
Instead of attaching my artificial crown by a screw passing vertically into the
root, I may proceed as follows:-
This invention will be readily understood from the accompanying Drawings
Figures 28-29 and 30 in which A represents a prepared tooth. B the cap to be
applied thereto, and C the screw to be used to hold the same together. The root A
is first properly prepared and shaped to receive the metallic cap or support B. As
shown B is shaped to correspond with the form of a tooth crown. The cap being
placed in position upon the root a hole is laterally drilled as shown at D through
the cap and into the root, and the pin or screw is then driven or placed in situation
in said holes so as to lock the cap and root firmly together. This method of
attaching a root to a cap prevents the longitudinal withdrawal of the cap from the
root without splitting the root while by the methods heretofore in use, if the
cement within the cavity in any way lost its hold the cap became liable to be.
longitudinally withdrawn from the root.
Figure 28 represents the prepared root, Figure 29, the cap to surround the same
and Figure 30 the attaching screw.
My improvements are however principally valuable in supporting several teeth
upon a bridge between two or more roots. By this improvement the denture is
supported upon bearings upon the natural teeth or roots which prevent the

page_text: displacement of the denture by vertical pressure and without necessary contact
with the gum.
By my improvement any number of teeth from one to a full set, can be readily
applied to any mouth, provided there be suitable supporting teeth or roots.
In applying my invention, in case one or more of the incisors or canines is to
be used to support the bridge, I suitably prepare the same by cutting it off at or
near the margin of the gum, leaving a preferably square surface there. The
method of preparing this root will form the subject of a separate application.
I then prepare a suitable cap or cup to be slipped over said prepared root, which
should project beneath the free margin of the gum. This cap should be closed
hermetically at the outer end, and, when in position should absolutely protect the
end of the root and take such a bearing upon the root or tooth as to be immoveable
under vertical pressure It may be and preferably should be additionally
strengthened in its position by a pin projecting upward into a suitably prepared
cavity in the root, and there cemented. I do not ordinarily cut away a bi-cuspid
or molar tooth, but prepare a suitable cap to cover the same. The cap should
preferably be in contact with the tooth or crown throughout its entire extent and'
especially under the margin of the gum. These caps and the roots being so
prepared I then build up between the caps a bridge support preferably of metal.
I prefer to use for my base a strip of suitable alloy. The artificial teeth are
applied externally to this support and soldered thereto by means of platinum pins
baked into the porcelain, or otherwise mechanically attached, and especially for the
molar and the bi-cuspid teeth the metal portion should project over the wearing
surfaces, or be arranged so as to constitute the masticating surface, so that the
grinding action may be taken up by the metal instead of on the porcelain. The
reason of making this wearing surface of gold, is, that if the artificial porcelain
teeth are applied so as to receive pressure and the full force of the jaw is applied
to their ends they might be separated from the supporting bridge. By the
described construction the teeth are so supported that in masticating the force is
applied to the metal and there is no pressure applied to drive the teeth away from-
their support.
.
The bridge between the cups and the teeth supported thereby, are free from
contact with the gum, the natural teeth or roots constituting the sole support of
the denture.
By thus supporting the denture that its bearing is solely against the teeth or
roots. I avoid any lateral draft strains or wrenching of the latter and also
absolutely prevent any abrasion or wounding of the sensitive gum surfaces which
are barely in contact, if at all with any part of the structure, the rigidity of which:
between its supports prevents it from springing or yielding so as to take any other
bearing while the positive bearings at the supports prevents the denture slipping
thereon against the gums.
My Invention is clearly illustrated in the accompanying Drawings, in which
Figure 31, represents a view of a prepared jaw to which my invention is to be
applied; Figure 32, a view of the artificial denture ready to be applied to the jaw
showing the methods of attachment, Figure 33 an under view of the same shewing
the relation of the grinding surfaces to the porcelain teeth Figure 34, the method
of attaching the cuspid teeth to the root showing a section of the artificial denture
in position. Figure 35 is a sectional perspective view looking from the inside of
the mouth and Figure 36 is an enlarged section of Figure 33..
These views represent. a full set. In preparing my artificial denture I take a cast
of the mouth in the usual way and then prepare a metallic strip of suitable con-.
figuration to which the artificial teeth or crowns are to be attached. I properly
prepare the roots for the reception of the caps or cups which afford the desired
bearings on roots or teeth of which one should be at either end of each section of
the artificial denture. As shown four have been provided. These having been
properly arranged with relation to the bridge or strip of metal upon which the
teeth are to be placed I then place the whole in a suitable investment and attach_

page_text: .\:
the teeth together by means of solder, preferably gold solder, and the appliance
will then present the form or configuration shown in Figure 32. The artificial
denture so prepared may then be readily applied to the mouth..
In my Drawings A represents generally the jaw; B the prepared tooth crown;
a the cuspid roots ready prepared preferably drilled with the holes C.: b the.
molar roots or teeth which need not be drilled. d and e. represent the cups ready
to be attached to the roots or teeth b and a. f represents the pins which enter the
holes c. When properly. applied this denture will be as firm in the mouth as the
natural teeth are, and will of course protect the natural roots or teeth from decay,
the bearing cups only having contact with these roots or teeth, the bridge and teeth
being supported away from the gum, as shewn in Figure 35. Partial sets containing
a greater or less number of teeth may be readily applied.
of
It will be observed that the cups or sockets surrounding the roots as distinguished
from bands having no bottom or closed; form an essential and very important part
f my combination, because, when bands are used, the great force due to the closure'
of the jaws is liable to force the denture against the gum, while by my invention
the cup has a bearing upon a positive face or shoulder and supports the pressure.
Without this improvement the bridge is liable to be easily separated from the
supporting teeth or roots. Moreover by my improvement substantially no cement
is required to prevent vertical motion, since the bearing is always upon the roots'
and merely enough attachment is required to prevent the withdrawal of the denture.
from the roots, the cement being used to fill the interstices. .
In certain cases when the crowns have become loosened from the supports it is
important to be able to place them readily. It has been found in practice in the
preparation and use of the kind of work just described that the crown will sometimes
chip or split or become loose, and the substitution of a new crown thus become
necessary.
.
It has heretofore been necessary to remove the ferrule and its attachments from
the root in order to replace, the crown; but I have devised a method of replacing
an artificial crown upon structures of that character, leaving the attaching ferrule
connected with the root. In practice such artificial crowns are attached generally
to a backing by solder or similar material. In case of accident I remove the crown,
from such backing or support and drill through the backing one or more holes for
the reception of the attaching holders.
1
The construction of such tooth crown will be readily understood from. the
Drawings in which Figure 37 represents the tooth crown as prepared ready for the:
application, Figure 38 a section of the same through the line x. x, Figure 39
represents the attaching contrivances so arranged as to hold the artificial tooth
crown in its place, Figure 40 represents another method of attaching my locking
tubes. Similar letters refer to similar parts C represents the artificial tooth crown,
which may be made of porcelain or other suitable material. In the process of
manufacture one or more tubes preferably two are fastened in said tooth in the
manner-shown in Figure 2. These tubes may be made of any. suitable metal, as
for instance platinum. The inner ends are spread out within the porcelain so as to
lock the tube firmly, or the usual pins as shown in Figure 40 may be employed
and the tubes slid over them and soldered thereto. By this means the ordinary
crown may be used. I prefer however the method shown in Figure 38.. In order
to attach said crown to the metallic backing, holes corresponding to the tubes A. A.
are drilled, and the crown put in position said tubes A. A. projecting through the
backing and into the mouth of the cavity. By a suitable instrument conforming
to the shape of the crown, and having a mechanical spreading contrivance within,
the inner ends of the tubes A. A. are spread or eyeletted as shown by B. B. thereby
locking the tube firmly in position. Larger pins, similar to the pins D. D. shown
in Figure 40 might be. used and screw threads cut thereon, and by means of the
nuts.on the inner ends the crown might be drawn up close to the backing, but I
prefer the method.shown in Figures 37, 38 and 39.

page_text: As there is a greater liability in this kind of work for artificial porcelains to be
turned from their bearings, I have devised a new holding device, by which such
porcelains may be readily and firmly fastened to the supporting bridge or other
support. This improvement consists in fastening devices, constructed as fully set
forth herein after, and placed on the top and back of porcelain teeth, thereby
enabling such porcelain teeth to be firmly held in position on their supports.
My invention will be readily understood from the accompanying. Drawings in
which Figure 41 represents a front view, and Figure 42 a back view of a tooth
crown so prepared. Figure 43 a view of the fastenings arranged to be soldered
and Figure 44 a section through Figure 42 on the line x. x.
My artificial tooth crown is prepared as follows. Metal ribbons or strips are
bent into the form shown in Figure 44. Two of these A and B are then placed in
situation in the paste before baking. These strips should not be bent close together
throughout their entire length, but should have a loop at their double end as is
shown in Figure 44. The paste having been built up around these bands or holders,
the porcelain tooth is to be baked in the usual way, and when removed, will
present the appearance shown in Figures 41 and 42. When desired for use, the
strips may be bent down as shown in Figure 43, in which condition they are
readily fastened by the investing solder when the tooth crown is to be placed in
situation. The upper pin in this case serving to prevent the downward motion
of the tooth crown which is very liable to occur in case of only one holding
device.
In applying the bridge work heretofore described it sometimes occurs that the
gum between said roots from which the teeth have been extracted has shrunk
away from its natural position, and therefore, if the bridge be constructed as shown
in said application, there will be a space between the gum and the bridge,
presenting an unsightly appearance. In order to avoid this difficulty, I proceed as
follows. Having properly prepared the roots, I then prepare the bridge and teeth-
I prefer to make the backing both of the artificial crowns and of the artificial gum
to be described, of a continuous plate of platinum. This platinum is to be soldered
to the backs of the porcelain teeth preferably by pure gold solder, and then upon
the face of this is to be applied a continuous gum preferably of porcelain. I shall
not particularly describe the method of attaching such artificial gum to metal, the
same being well known in the art." Instead of porcelain in certain cases I may
use hard rubber or celluloid, but I prefer the porcelain.
My invention will be clearly understood from the accompanying Drawings in
which Figure 45 represents a section through my artificial denture and the gum;
Figure 46, a front view of the prepared jaw before the bridge is applied; Figure 47
a front view of the bridge, and artificial gum, Figure 48 a back view of the same.
A represents the natural gum, B the artificial denture. C shews the continuous
inetallic backing preferably of platinum attached to suitable sockets D. E repre-
sents the artificial porcelain teeth and G the artificial gum of porcelain or other
suitable material.
This artificial gum as will be seen, is supported upon platinum backing C, and
when in position overlaps the natural-gum as shown in Figure 45.
I shall not fully describe the method of preparation of the bridge and of the
porcelain gum, the same being known in the art.
I claim
1st The process of preparing roots for the reception of artificial dentures which
consists in grooving the same by opposite grooves and then suddenly removing the
crown from the root by a suitable forceps substantially as described.
2nd The process of preparing a root for the reception of an artificial denture
which consists in removing the crown from the root by a suitable contrivance and
then immediately expelling the nerve from its cavity by driving a suitably shaped
piece of wood into the nerve cavity, substantially as described.
3rd The process of treating and preparing the roots of teeth the same consisting

page_text: in suddenly expelling the nerve from its cavity as set forth and then instantly
filling the nerve cavity with a wooden plug, substantially as set forth.
4th The process of preparing a 'root for the reception of an artificial denture
which consists in grooving the same, 'in' cutting off the crown from the root by a
suitable forceps; in immediately driving into the nerve cavity a suitably shaped
piece of wood, in removing the same and cleansing the nerve cavity, and in imme-
diately plugging or filling the upper part of the nerve cavity by driving in another
piece of wood, substantially as described.
5th The process of treating teeth to remove the nerves, the same consisting in
isolating the tooth to be treated and then subjecting the latter to the action of a
jet of volatile liquid until the nerve within the same is benumbed, substantially as
set forth.
6th The combination of a prepared root having its natural terminal contour near
the margin of the gum, with an enclosing cap attached thereto for supporting an
artificial denture, substantially as described.
7th The combination of a prepared root 'having. its natural terminal.contour
near the margin of the gum, with an enclosing cap attached thereto, and with an
artificial porcelain or other crown supported by said cap, substantially as
described.
8th The combination of a prepared root having its natural terminal contour
near the margin of the gum with an enclosing cap attached thereto the said cap
being attached to the root by a pin. or suitable attaching contrivance passing
upward and into a suitable cavity in the root, substantially as described.
9th The combination of a tooth crown, a metallic backing soldered to said crown'
and a pin firmly soldered to said artificial backing and secured to and passing
through a ferrule adapted to surround the root, substantially as described.
10th The combination of the crown, provided with a suitable attaching pin the
backing plate and the metallic backing united to ferrule and pin substantially as
described.
11th The combination of the crown metallic backing united to protecting plate
and pin, the root and cement uniting the pin to the root, substantially as
described.
-
12th The method of preparing an artificial denture which consists in suitably
preparing a root for the reception of a surrounding ferrule, retaining the natural
terminal contour near the gum, in placing upon the back of a suitable tooth crown
a backing of platinum or other suitable metal in soldering said backing to the
tooth crown by means of pins or clamps projecting through said backing, and to
the ferrule, substantially as described.
'
13th The method of preparing an artificial denture which consists in suitably
preparing a root for the reception of a surrounding ferrule, in placing upon the
back of a suitable tooth crown, a backing of platinum or other suitable metal, in
soldering said backing to the tooth crown by means of pins or clamps projecting
through said backing, and to the ferrule, in placing said prepared crown upon the
tooth, and in connecting the root with the crown substantially as described.
14th The combination of a prepared root having attached to it permanently au
enclosing cup with a removeable denture or tooth crown, substantially as
described.
15th The combination of a root with an enclosing cap or covering sealing, the
end of said root said cap or covering having attached to it a threaded tube
projecting upward into said root, substantially as described.
16th The combination of the root a. enclosing cap e. and closed threaded screw d.
with an artificial denture or tooth crown F, attached thereto by screw g. substantially
as described.
17th The combination of the root a, enclosing cup e, artificial crown or denture f,
and screw g, the upper part of said denture f, surrounding and fitting closely the
ferrule of the cup e, substantially as described.
5
18th The combination with a natural root of a metallic attachment, covering the

page_text: end of the root, a denture with a flat upper face adapted to fit the face of said
attachment, and a connecting screw, substantially as set forth.
19th The combination of a denture comprising a metal bridge supporting two or
more teeth, prepared roots or natural teeth with attachments secured thereto, and
detachable receiving devices whereby the denture is detachably connected to said
roots or teeth at different points, as set forth.
20th The combination of a root and a hermetically closed cap placed over and
enclosing the end of said root or tooth, and a screw passing through the cap and
root and projecting substantially at right angles to the major axis of the tooth,
substantially as described.
21st An artificial denture consisting of a metallic bridge, artificial teeth supported
thereby upon the outer side thereof, and two or more cups or caps adapted to
natural roots or teeth and attached to the bridge whereby the said teeth or roots
are made the sole bearings of the denture, substantially as set forth.
22nd An artificial denture which consists of two cups or sockets adapted to fit
over and surround two teeth or roots connected together by an intermediate bar or
support upon which artificial teeth are mounted, which bar constitutes the masti-
cating portion of the denture, for the purpose of preventing the strain upon the
artificial teeth substantially as described.
23rd The combination with fixed natural teeth or roots, of an intermediate
bridge supporting artificial teeth, and provided with caps having their bearings
upon the ends of such natural teeth and secured thereto by fastening means,
substantially as set forth.
24th The method of setting artificial porcelain teeth which consists in drilling
through the hard supporting backing one or more holes corresponding to a
supporting pin or pins, and in then spreading or increasing the size of said pin or
pins, at its inner end for the purpose of locking said porcelain teeth after they are
in position substantially as described.
25th The combination of an artificial porcelain tooth with one or more tubular
locking pins adapted to be spread at their inner ends thereby locking the crown
in position, substantially as described.
26th The combination of an artificial porcelain tooth and a tubular pin attached
to a pin baked in the tooth, substantially as described.
27th The combination of an artificial porcelain tooth with two holding devices
consisting of flat strips of metal bent double, to form loops at the inner ends, one
of said holding devices projecting at the top and the other at the back of said
artificial crown, substantially as described.
28th The combination of the metallic bridge C, provided with sockets or holding
devices D and extending between its supports, and free from contact with the gum,
with the artificial tooth E, and the artificial gum G, extending above the bridge
and covering the space between the latter and the natural gum, substantially as
shown and described.
In witness whereof I the said Sydney Pitt have hereunto set my hand and
seal this fifth day of May in the year of our Lord One thousand eight
hundred and eighty three.
SYDNEY PITT (L.S.)