IMPROVEMENTS IN ARTIFICIAL TOOTH CROWNS, AND MEANS FOR ATTACHING THE SAME TO ROOTS OF NATURAL TEETH
Year: 1885

page_text: I, CALVIN SUVERILLE CASE, of the City of Jackson, in the County of Jackson,
and State of Michigan, United States of America, Dentist, do hereby declare the
nature of my invention for IMPROVEMENTS IN ARTIFICIAL TOOTH CROWNS, AND
MEANS FOR ATTACHING THE SAME TO ROOTS OF NATURAL TEETH, and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement:―
My invention relates to a new and improved artificial tooth crown adapted to be
attached to the stump or root of a natural tooth; and to certain improved devices
for effecting such attachment, as will be fully hereinafter explained.
Figure 1 is a side view of a crown for an upper incisor tooth.
Fig. 2 is a similar view of a bicuspid tooth crown.
Fig. 3 is a transverse section on the line x a, Fig. 2.
Fig. 4 is a vertical section of the root or stump of a natural tooth, the artificial
crown, and the means for connecting them, the parts being shown separated.
Fig. 5 is a similar view, after the parts have been united.
Fig. 6 is a sectional view of the completed tooth.
In the drawings A represents the crown made from porcelain or any other
desired material, and provided with a small tube B, preferably of platinum,
extending through it centrally, it being placed in such position during the process
of manufacturing the crown. These crowns are made of various shapes, sizes and
colors to match the other teeth of the user, as is common in this class of work.
F is a small pin or wire placed in about the center of the crown A, and adapted
to give additional strength to the tooth, and reduce the danger of fracturing or
breaking the crown. It is provided at its ends with small heads f which give it a
firm hold in material of which the crown is composed, and is bent partially around
tube B, as shown in Fig. 3.
When it is desired to attach my improved crown to the root or stump R of a
natural tooth, it (the root) is first properly dressed off upon its surface, and filled,
if necessary. I then insert therein a screw-threaded post or stem E, either by

page_text: '
drilling a hole in the root into which the post is tightly screwed, or by filling the
cavity, should there be one, in the center of the tooth with any desired kind of
filling or cement into which the post is inserted. The lower part of the aperture in
the root R is somewhat enlarged, as at 7, forming an annular cavity around the
post, extending a short distance into the tooth towards its center.
In order to better unite the crown and the root, and to give a comparatively
long and rigid bearing for the parts which connect the two, I insert into and solder
to the tube B a smaller tube C, of gold, silver, or other metal, which projects a
This tube C is of such
short distance above the upper face of the tooth crown.
size that it closely fits into the tube B, and also fits over the post or stem E, and is 1
cut of such length that it completely fills the cavity r, which has been prepared for
its reception.
1
After the engaging faces of the root and crown have been properly ground to fit
each other accurately, the tube C is slipped over the post E, and into the cavity ?.
When the parts are thus brought close together, the screw threaded post E extends
through tubes C and D, and projects a short distance below the lower end of the
tube B I then take an internally screw-threaded cylindrical coupling tube D, of
such diameter as to closely fit into the platinum tube B, and screw it upon the
post until its end comes in contact with the shoulder e formed by the lower end of
the short tube C, when by a further movement of the cylindrical coupler D the
parts are tightly forced together. The projecting ends of tube B and D, and
post E, are then cut away, and the exposed surface polished, thus completing the
tooth.
In place of the cylindrical coupler D, I may employ a short nut to engage with
post E, and thus connect the crown with the natural root: but I prefer the
construction shown, as it entirely closes the cavity within the tooth, and prevents
the entrance of moisture, or small particles of food.
By attaching the above described crown in the manner set forth, a tooth is
formed which can scarcely be distinguished from a natural tooth, and which well
serves for the process of mastication. It will be seen that the connection between
the two parts of the tooth consists of two concentric tubes surrounding and attached
to a post or stem, situated in the root of the natural tooth, one of the tubes carried
by the artificial crown projecting above the surface of the crown and entering the
angular cavity surrounding post E. This arrangement makes the tooth much
stronger than if the ends were simply flush with the surface of the crown.
While I have only shown my invention as applied to a front upper incisor tooth,
for the purpose of illustration, yet it will be understood that it is applicable to any
of the teeth, whether incisors, bicuspids, or molars.
I do not wish to be limited to all the details herein shown, as some of them may
be omitted, or others substituted therefor, without departing from the spirit of my
invention.
instead
For instance, I may extend the tube B above the surface of the crown,
of using the separate tube C, it being provided with a shoulder or stop of any kind
to receive the thrust of the end of the coupling tube or cylinder ]).
But the construction shown is much preferable, as it is often necessary to grind
the crown to fit it to the root before attaching it, and the presence of a tube
projecting above the surface of the crown would interfere with such grinding; this
being one of the objections which led me to use the tube C, which latter is soldered
into the tube carried by the artificial crown, after the latter has been ground:
: It will, of course, be understood that cement of some sort will be used between
the adjacent faces of the two parts of the tooth.
I am aware of the fact that a short tube threaded both internally and externally,
has been inserted into the natural root, and that a screw has been used therewith
to hold the crown, said screw. engaging with the internal thread of the tube in the
root. My construction has the advantage that the socket required in the natural
root is of minimum diameter, and therefore the root is left as strong as possible
F
E

page_text: Moreover, the inserting of a long post in the root can be effected much more easily
than can the inserting of the short tube (alluded to above), terminating at the
surface of the root. So, also, by properly shaping the cavity r and making the
tube C of such size and form that it shall fit accurately the inner walls of that
cavity, I secure important results in the way of firmly supporting the crown which
I believe cannot be attained by any known construction.
I am aware that a tooth crown has been made with a short tube projecting from
its face and adapted to enter a cavity within the root but in such prior instance
the tube did not fit closely the inner walls of the tooth cavity, but, on the contrary
there was a sufficient annular space between the tube and the tooth to receive a
cement used for the purpose of securing the crown firmly in place. Again, a
drainage tube has been inserted firmly in the root of a tooth in such manner as to
pass centrally or thereabouts through the crown; but I believe I am the first to use
a tube projecting from the face of the crown and fitting tightly an excavated
cavity in combination with a post seated firmly in the root and passing through
the tube and crown in combination with means of any sort for securing the tooth
firmly to the post so as to support the crown positively against being pulled off
from the post.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The combination, with an artificial tooth crown, of the strengthening pin, or
wire F, curved around the central portion of the tooth, and secured therein during
the process of baking, substantially as set forth.
2. The combination, with an artificial tooth crown, and a tube or rod passing
through it, of the strengthening pin, or wire F, curved around the said tube or rod,
and having enlarged heads f, substantially as set forth.
3. An artificial tooth crown having a tube situated centrally therein, and
projecting beyond the face of the crown which lies next the natural root,
substantially as and for the purposes set forth.
4. An artificial tooth crown having a tube situated centrally therein and
projecting beyond the face of the crown which lies next the natural root, and a
stop or shoulder within the tube, substantially as and for the purpose set forth.
5. The herein described artificial crown A, provided with tube B, and smaller
tube C, projecting from the end of tube B, and forming a shoulder c therein,
substantially as and for the purposes set forth.
6. An artificial tooth crown, having a tube situated centrally therein, and a stop
or shoulder within the tube, substantially as set forth.
7. The combination with the root of a natural tooth, of an artificial crown, a
screw-threaded post inserted into the natural root, and projecting through the
crown when the latter is in place, and a nut which engages with said screw-
threaded post and unites the crown with the root, substantially as set forth.
8. The combination with the root of a natural tooth, provided with an excavated
cavity, of an artificial crown having a tube projecting from its bearing face and
adapted to fit closely within the said cavity, a post passing through the tube, and
means for connecting the crown to the post, substantially as set forth.
9. In combination with the root of a natural tooth having the cavity r of the
screw-threaded post, the crown having a tube extending centrally through it, and
adapted to enter the cavity 7, the screw-threaded coupler D, and a stop with which
the coupler engages, substantially as set forth.
10. In combination with the root of a natural tooth, a threaded post inserted
into the root, and projecting beyond the outer end thereof, a crown having an
aperture whereby it can be slipped over the outer end of the post and a threaded
coupler or nut which bears positively against the crown and engages with the
projecting part of the post, substantially as set forth.

page_text: 11. The combination, with the root of a natural tooth provided with the cavity.
of the artificial crown, the tube B passing through the crown, the smaller tube C
seated in tube B, and forming a shoulder therein, as at c, and adapted to enter
cavity r, the screw-threaded post or stem E seated in the root, and adapted to
extend through tubes B and C, when the parts are in position, and the coupling
tube D adapted to enter tube B, and engaged with the post to unite the parts
together, substantially as described.