Improvements in Artifloial Tooth Crowns
Year: 1899

page_text: Date of Application, 7th Nov,, 1899-Accepted, 9th Dec., 1899
774
Improvements in Artifloial Tooth Crowns,
I, LEWIS SWEETMAN SEELEY, Surgeon Dentist, of No. 182 East 82nd Street,
Borough of Manhattan, City, County and State of New York, United States of
America, do hereby declare the nature of this invention, and in what mannet
the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
The invention relates more especially to tooth-crowns which are fitted and
attached to a natural root. The objects are so to construct the shank or pin,
with which the crown is provided, as to afford a reliable means for securing
the crown to the root, the shank also being adaptable to a double rooted tooth
as well as to a tooth having only one root.
To these ends the invention consists in the construction of a tooth crown
having a pin or shank with the capabilities hereinafter more fully described
and pointed out or indicated in and by the claim.
In the drawings Figure 1 is an enlarged view of a tooth-crown with its
doubled metal pin or shank: Figure 2 is an enlarged sectional view of the
same and of a root to which the shank is secured; Figure 3 is a detached detail
of one form of the shank; Figure 4 is a sectional view of a crown and shank,
the latter having its extremities formed with a head or turned at an anglo
within the crown: Figure 5 is an enlarged sectional view of a crown shank
and root, the shank being expanded within the cavity of the root, somewhat
above the return-bend.
In these drawings A represents the crown which may be made of porcelain
or plastic material. The upper end a of the shank B is inserted in the material
while plastic and baked therein in the usual manner.
The shank is made of
a strip of metal or wire which is doubled so that the return-bend b forms the
end; the metal strips of wire may he round, flat, or angular, but I prefer the
latter, and they are usually of platinum or platino-iridium, though any other
suitable metal may be used.
The two parts may be brought close to each other at or near the return-bend
or end of the shank, thus allowing a taper, and even a point to be made at
the extremity which extends deepest into the canal of the root C of the natural
tooth. This taper or point may be made either at the time of manufacture
or when the crown is being fitted to the root on which it is to be secured. If
the tooth has a double root, the return-bend may be cut or filed so as to allow
of a separation of the parts of the shauk, which, being spread, will form two
shanks, oue for each root.
A space is left between the two parts after leaving the return-bend, or
they may be expanded as at 1, Figure 5, so as to fit an enlarged cavity or admit
the cement or filling, which will form, as it were, a bridge or solid mass across
the canal of the root. This, together with the hold which the cement takes on
the walls of the root, will secure the crown more firmly than where dependance
is placed entirely upon screw-threads, flanges or other conformations on the
exterior of the shank.

page_text: The doubled metal strip or wire of which the shank is formed is capable of
being spread to extend across the cavity in the root, bracing the shank against
the sides thereof, and leaving the enlarged opening d between the strips, which
will be filled with the cement. Such adjustment and bracing of the shank
holds the crown steady while the cement is hardening or until it is set, and
also makes the crown much more firm, so that mastication of food is less
liable to jar or loosen the shank by a continued use of the tooth thus
repaired.
Moreover, a crown provided with a shank formed of a double strip of wire
such as I have shown and described, is simple in construction and cheap to
manufacture, in which particulars, as well as in its capability for adjustment
so as to form a brace in the root, my improvement presents important advan-
tages over other forms of crowns having shanks or pius as the same have
heretofore been constructed.
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 :-
.
A tooth crown provided with an open tapered shank formed of a single wire,
the two lengths of which are spaced apart and converged at their outer con-
nected ends, and baked with the crown at their inner ends, whereby the shank
will conform to an ordinary tapered tooth cavity or may be bulged outwardly
to conform to a cavity of different shape, or may be divided at its outer
extremity or point to form two prongs for a double cavity, substantially as
set forth.
Dated this 7th day of November 1899.
ALLISON BROS.,
Agents for the Applicant.