Improvements in or relating to Artificial Teeth.
Year: 1890

page_text: Date of Application, 2nd June, 1890-Accepted, 2nd Aug., 1890
COMPLETE SPECIFICATION.
Improvements in or relating to Artificial Teeth.
I, JAMES GEORGE MACCONAGHY of 229 Rue St. Honoré Paris in the Republic of
France, Dentist, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
The enamel tooth crown cap or casing forming the subject of this invention is
that part of an artificial tooth which consists of the external part or enamel covering
such as natural teeth are provided with and which assumes the shape of a cap or
sheath.
It consists of two parts ;-one mineral B C, B'C' B C being the cap proper ;
and the other made of metal consisting of two platina plates or arms 11, 111, 12 12,
secured to the internal walls of the cap or casing.
In the accompanying drawing
Fig. 1 is a front view of a tooth A and of my improved tooth casing applied to it,
11 being the metal plates.
Fig. 2 is a side view of the tooth A', B₁ ( being the enamel casing and one of
the metal blades or plates.
Fig. 3 is a section of the cap or casing consisting of the solid mineral portion B C²
the deep hollow space or cavity D2 and a metal plate attached to the inner wall of
the cap.
The cap is a simple shell which owing to its shape and the manner in which it is
secured to the tooth acquires when once applied the required amount of resistance.
It is intended to cover the portion of the crown of the tooth (previously prepared
for its reception) comprised between the lips the sides and a portion of the surface of
the tongue.
It is therefore hollowed out in the manner shown in D2 Fig. 3 and consists of a
thin plate except at each of the angles formed by the sharp edges and the sides of the
crown, where it is thicker so as to afford a strong point of support to the metal
portion.
Each of the two platina plates of this metal portion is embedded within the
substance of the mineral portion at its strongest part while the remaining portion of
the plate is left free so as to allow of its being adjusted to the back surface which
corresponds to the neck of the natural tooth. In this manner the two arms meet at
their forward ends; and it will be observed that these arms are soldered to the
mineral portion so that the whole forms a complete flange surrounding the crown of
the natural tooth on all sides except the side facing the tongue which may be left
open or enclosed as desired.
Advantages-The enamel tooth crown cap or casing herein described offers the
following important advantages ;-
(1) It is adapted to replace natural enamel on teeth that are laid bare or denudated
or in cases of caries or extensive erosion of the enamel especially on the sides of
front teeth facing the lips as in these cases "filling" is unadvisable not only by
reason of its unsightly appearance, but also on account of the decayed condition of
the remaining portion of the crown which nevertheless it is desirable to preserve to
avoid destroying the vitality of the tooth.
(2) The enamel cap or casing differs from other artificial crowns which when
applied involve the sacrifice of the whole or at least the greater part of the natural
crown and consequently the devitalization of the tooth and which mainly depend for
their support on a pin inserted into the root of the tooth. The enamel cap is thus
an advantageous substitute for all other artificial teeth crowns, if used for teeth the
crowns of which are lost or decayed; while in connection with a pin, it is capable of

page_text: by far a greater number and variety of useful applications offering as it does
exceptional facilities of adjustment.
(3) The enamel cap or casing allows of what may be called a conservatory course
of treatment while at the same time it imparts a life-like appearance to diseased
or deformed teeth which otherwise would have to be given over as irremediably lost.
(4) The casing or cap may be employed with or without a pin as required. When
combined with a pin it is preferable to all other artificial crowns of teeth used for
the same purpose.
(5) It is endowed with greater resistance than a tooth made wholly of porcelain
for this fundamental reason that the part where the greatest strength is required is
that formed by the upper edges of the metal portion.
(6) Where the teeth being situated in the jaws are liable to meet or cross frequently,
the enamel cap will offer greater convenience than a porcelain crown owing to the
facility with which the joint may be accommodated without materially diminishing
the strength of the artificial crown.
(7) In the case of the root occupying an inclined position in the jaw the enamel
cap or casing may be adjusted in position by first securing the pin without its being
necessary to follow the direction of the root.
(8) The cap or casing enables the special ring to be dispensed with which is
applied to the root when it is to be provided with an artificial crown, inasmuch
as it is itself a combined crown and ring.
(9) If necessary it may be used in connection with a pin in the shape of a tube
wide enough to render the root still accessible after the crown piece is arranged in
position. This is an invaluable advantage in case there should be any reason to
fear a disorder in periosteum.
(10) The junction of the mineral and the metal portions is just as strong as any
connection used in ordinary mineral teeth and the method of securing the enamel cap
to the remaining portion (if any) of the natural crown by means of suitable cement;
or if the crown be lost totally by a combination of cement and amalgam ensures the
maximum of strength attainable.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is ;-
The enamel tooth crown cap or casing consisting :-
(1) Of a deeply hollowed out portion made of mineral substance and assuming
the shape of a shell slightly turned in on the side facing the tongue towards the
sharp edge of the tooth.
(2) Of accessory junction pieces formed by two plates or wires made of platina
gold or other suitable substance and secured to the body of mineral substance in the
manner described above or otherwise so as to project on both sides of the shell,
substantially as described and illustrated in the accompanying drawings.
Dated this Second day of June 1890.
W. P. THOMPSON & BOULT,
Agents for the Applicant.