Improvements in and relating to Artificial Teeth.
Year: 1893

page_text: Date of Application, 29th Sept., 1893
Complete Specification Left, 7th June, 1894-Accepted, 7th July, 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Artificial Teeth.
I, ROBERT WIESENDANGER, of 33 Steindamm St. Georg, Hamburg, in the
Empire of Germany, Dentist, do hereby declare the nature of this invention to
be as follows :—
My invention relates to artificial teeth and comprises a method of repairing
teeth by completely removing the stumps or remainders of the crown which may
still exist and also-cutting away the roots excepting their outer portion, in order to
afford space for the artificial roots of the new crown to be provided. The
remainders of the natural roots which have grown and are held firmly in the jaw
then serve as it were as shoes for the artificial roots, and supposing there is a firm
connection between the primary and secondary roots, and between the crown and
secondary root, a tooth repaired in this manner possesses the same strength as a
sound natural tooth. As regards the durability of teeth thus repaired this new
method offers a great advantage as compared with the methods heretofore
practised, inasmuch as by the removal of the unenamelled portion of the natural
root the upper edge of the latter becomes very narrow and, in contra-distinction to
the gold plate covering the upper root surface, which frequently leaves its position,
the channels existing in the root are closed with absolute certainty by means of the
cement or amalgam introduced between the crown, the primary and the secondary.
root. This layer of cement or amalgam will not be liable to much wear, because it
is not, as has heretofore been the case, the upper surface of the root which takes.
up the pressure exerted upon the tooth in the perpendicular direction to the jaw,
this pressure being taken up by the entire surface of the root exactly as in the case
of the natural tooth.
Various modes may be employed of fixing the secondary root to the crown.
According to one mode I fill the cavity of the natural root, and also the artificial
crown of the tooth which is suitably hollowed out, with cement or amalgam so that
after the hardening of the filling material the crown and root will be rigidly
connected with each other, and that a thin layer of the same will make a joint
between the edge of the natural root and the edge of the crown, while that position
of the filling material which is contained in the cavity of the natural root.
constitutes the artificial root. As a rule the cement or the amalgam will adhere to
the inner surface of the cavity in the root, which has intentionally not been made
smooth, while the cavity in the crown must necessarily be undercut. Sometimes it
will however be necessary to shape also the cavity in the root in this manner,
which may take place by cutting recesses in the remaining wall of the root or
forming projecting edges thereon. In the former case the filling of cement or
Such a connection
amalgam presents rings corresponding to the aforesaid recesses.
1
of the artificial crown with the artificial root may also be effected by boring two or
more holes which are inclined relatively to each other into the crown in lieu
of providing an axial bore which widens towards its bottom, the filling material
being pressed into the said holes when forcing the crown upon the root of the tooth.
All these connections produced by the aid of cement or amalgam have in common
the double cone shape of the plug at the joint between the crown and the root,
which latter requires to be hollowed out in accordance with this form, so that in use
no molecular displacement will be possible at the aforesaid joint and that there will
be a minimum pressure upon the plug, while the latter covers the root so as to
completely protect it from caries.

page_text: According to another mode I fix the artificial root, which in this case is made in
one piece with and of the same material as the crown, in the natural root under the
same favourable circumstances as stated in respect of the first mode hereinbefore
described by providing the natural root with recesses and the artificial root with
annular projections, or vice versa. Between the two roots I then insert a layer of
cement or amalgam. The teeth repaired according to this improved method do not
differ outwardly at all from natural teeth, as the artificial crown is connected with
the natural root without any visible means. As compared with the natural teeth
the former possess however the advantage of being completely protected from
caries.
COMPLETE SPECIFICATION.
Improvements in and relating to Artificial Teeth.
j
I, ROBERT WIESENDANGER of 33 Steindamm, St. Georg in the City of
Hamburg, in the German Empire, 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:-
My invention relates to the connection of artificial teeth to natural roots in the
jaw by means of a kind of artificial root made from cement, caoutchouc, amalgam
or like plastic material, and to the artificial teeth appropriated for the said
purpose.
For carrying this invention into practice the stumps or remainders of the crown
which still exists with the tooth to be repaired is completely removed and the roots:
are also cut away excepting their outer portion, in order to afford space for the
artificial roots of the new crown to be provided.. The remainders of the natural
roots which have grown-and are held firmly in the jaw then serve as it were as shoes.
for the artificial roots and supposing there is a firm connection between the primary
and secondary roots, and between the crown and secondary root, a tooth repaired
in this manner possesses the same strength as a sound natural tooth..
As regards the durability of teeth thus repaired this new 'method offers a great
advantage as compared with the methods heretofore practised, inasmuch as by the
removal of the unenamelled portion of the natural root the upper edge of the latter
becomes very narrow and, in contra-distinction to the gold plate covering the upper
root surface, which frequently leaves its position, the channels existing in the root.
are closed with absolute certainty by means of the cement or amalgam introduced
between the crown, the primary and the secondary root. This layer of cement or
amalgam will not be liable to much wear, because it is not, as has heretofore been
the case, the upper surface of the root which takes up the pressure exerted upon the
tooth in the perpendicular direction to the jaw, this pressure being taken up by the
entire surface of the root exactly as in the case of the natural tooth.
In order to make my invention more clearly understood I will proceed to describe
it with reference to the accompanying drawing in which
Figure 1 is a sectional side elevation of a natural root cut away all but its outer
portion and an artificial tooth made according to my invention;
Figures 2 and 3 are sectional side elevations of two natural roots to which are
secured plugged artificial teeth according to my invention;
Figure 4 is a longitudinal section of a natural root cut out for the reception of the
plug proper for connecting an artificial tooth to the root;

page_text: Figure 5, is a perspective view of the connecting plug of plastic material in the
shape it takes up when filling out the cavities of the root (Figure 4) and the
artificial crown;
:\
Figure 6, illustrates a cross section of an improved artificial crown, and,
Figure 7, a modification of my improvements in the method of repairing teeth.
According to Figures 1-3 the cavity a¹ of the natural root a as well as that of
the suitably hollowed artificial crown b is filled with cement, amalgam or like
material so that after the hardening of the filling material e the crown and root
will be rigidly connected with each other, and that a thin layer of the same will
make a joint between the edge of the natural root and the edge of the crown, while
that portion of the filling material which is contained in the cavity of the natural
root constitutes the artificial root. As a rule the caoutchouc, cement or the-
amalgam will adhere to the inner surface of the cavity in the root, which has
intentionally not been made smooth, while the cavity in the crown must necessarily
be undercut.
Sometimes it will however be necessary to shape also the cavity in the root in
this manner, which may take place by cutting recesses a' in the remaining wall of
the root a or forming projecting edges thereon. In the former case the filling of
cement or amalgam will take up the shape, Figure 5, that is to say, it presents
rings on the part c' corresponding to the aforesaid recesses a³. In a similar
manner a connection of the artificial crown with the artificial root may be effected
by boring two or more holes which are inclined relatively to each other into the
crown (Figure 6) in lieu of providing an axial bore 6 (Figures 1-3) which
widens towards its bottom, the filling material being pressed into the said holes.
when forcing the crown upon the root a in the jaw. All these connections produced
by the aid of cement or amalgam have in common the double cone shape of tho
plug at the joint between the crown and the root, which latter requires to-be
hollowed out in accordance with this form, so that in use no molecular displacement
will be possible at the aforesaid joint and that there will be a minimum pressure
upon the plug b, while the latter covers the natural root so as to completely protect.
it from caries.
According to the mode, illustrated in Figure 7, I fix the artificial root d which
in this case is made in one piece with and of the same material as the crown b, in
the natural root a under the same favourable circumstances as stated in respect to
the first mode herein before described by providing the natural root a with recesses a
and the artificial root d with annular projections d', or vice versa.
Between the
two roots I then insert a layer e of caoutchouc, cement or amalgam.
The teeth repaired according to this improved method do not differ outwardly at
all from natural teeth, as the artificial is connected with the natural root in such a.
way as not to be visible. As compared with the natural teeth the former possess.
however the advantage of being completely protected from caries.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The method of connecting artificial crowns to natural roots of teeth in the jaw,
which consists in employing in lieu of the pins hitherto used to be imbedded in the
filling mass a sort of artificial root or plug of a plastic filling mass, such as.
caoutchouc, cement or amalgam, which is designed, when hardened, to rigidly
connect the hollowed natural root with the artificial crown of the tooth, substantially
as and for the purpose set forth.
2. An artificial crown of a tooth provided with a cavity so as to form sharp edges.
and having at its bottom an undercut bore b¹, or two or more holes 6', which
are inclined to each other, substantially as and for the purpose set forth.
3. An artificial crown of a tooth united with a connecting plug from cement,
caoutchouc, amalgam or the like plastic material, the shape of which being

page_text: obtained by impression from the conically hollowed-out natural root of the tooth, so
as to exactly fit into the cavity of the root, substantially as and for the purpose set
forth.
Dated this 7th day of June 1804
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.