IMPROVEMENTS IN THE PREPARATION AND FITTING OF ARTIFICIAL TEETH AND IN APPARATUS EMPLOYED THEREIN
Year: 1882

page_text: c5
LETTERS PATENT to Edward Reading of Sydney New South Wales, at
present residing at No. 14 Bedford Place, Russell Square in the County of
Middlesex for an Invention of IMPROVEMENTS IN THE PREPARATION AND
FITTING OF ARTIFICIAL TEETH AND IN APPARATUS EMPLOYED THEREIN."
Communicated to him from abroad by Dr. Henry Buttner of New York
United States of America
PROVISIONAL SPECIFICATION left by the said Edward Reading at the
Office of the Commissioners of Patents on the 19th June 1882.
EDWARD READING of Sydney New South Wales, at present residing at
No. 14 Bedford Place Russell Square in the County of Middlesex. " IMPROVE-
MENTS IN THE PREPARATION AND FITTING OF ARTIFICIAL TEETH AND IN APPARATUS
EMPLOYED THEREIN." [Communicated to him from abroad by Dr. Henry Buttner
of New York United States of America]
This Invention has for its object improvements in the preparation and fitting of
artificial teeth and in apparatus employed therein.
My improved process and apparatus are as follows:-
In order to prepare the natural root to receive the artificial crown I first form a
passage up the centre of the root or rather I enlarge the natural passage to a
standard size. I then cut down the end of the root to a true surface by means of
a rotating tool having a peg in the centre of the standard size which enters the
true hole already prepared in the root. This tool has cutting teeth to operate upon
the exposed end of the root and cut it down as far as may be required. Afterwards
I employ another tool also with a central peg of standard size and which has a
cutting ring around it such as to reduce the end of the root to a cylindrical form
upon the exterior. The cutting ring of the tool is made accurately to another
standard size so that the end of the root is reduced by incans of these tools both
within and without to standard dimensions. I now insert a metal pin of the
standard size to fit the hole into the prepared root, or if there be more than one
IDC 11

page_text: tooth to be fitted I insert a pin into each of the prepared roots. I then take the
form of the mouth in wax. The pins come away with the wax and I place upon
each of them a metal model of the prepared root. Such models form part of the
set of tools, they are pieces of brass bored and turned to the standard sizes. A
mould being thus prepared a plaster cast is made and the root models are found
in this cast truly in their places in exact accordance with their positions in the
mouth. The artificial tooth has now to be adapted to the model root.
A gold cap is used-it is of the standard size and has a central pin also of tho
standard size so that it fits very accurately the root model and the root itself.
Upon this cap a support for the tooth is fashioned in gold and to this the tooth
made to the proper form is fixed.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edward Reading in the Great Seal Patent Office on the
19th December 1882.
EDWARD READING of Sydney New South Wales at present residing at
No. 14 Bedford Place Russell Square in the County of Middlesex IMPROVE-
[
MENTS IN THE PREPARATION AND FITTING OF ARTIFICAL TEETH AND IN APPARATUS
EMPLOYED THEREIN." A communication to me from abroad by Dr. Henry Buttner
of New York United States of America.
This Invention has for its object improvements in the preparation and fitting of
artificial teeth and in apparatus employed therein.
My improved process and apparatus are as follows:-
In order to prepare the natural root to receive the artificial crown I first form a
passage up the centre of the root or rather I enlarge the natural passage to a
standard size. I then cut down the end of the root to a true surface by means of
a rotating tool having a peg in the centre of the standard size which enters the
true hole already prepared in the root. This tool has cutting teeth to operate upon
the exposed end of the root and cut it down as far as may be required. Afterwards
I employ another tool also with a central peg of standard size and which has a
cutting ring around it such as to reduce the end of the root to a cylindrical form
upon the exterior. The cutting ring of the tool is made accurately to another
standard size so that the end of the root is reduced by means of these tools both
within and without to standard dimensions. I now insert a metal pin of the
standard size to fit the hole into the prepared root, or if there be more than one
tooth to be fitted, I insert a pin into each of the prepared roots. 1 then take the
form of the mouth in wax
The pins come away with the wax and I place upon each of them a metal model
of the prepared root.
Such models form part of the set of tools. They are pieces of brass bored and
turned to the standard sizes.

page_text: A mould being thus prepared a plaster cast is made and the root model or
models if more than one is used are found in this cast truly in their places in
exact accordance with their positions in the mouth.
The artificial tooth has now to be adapted to each model root. For this purpose
I use a gold or other metal cap of a standard size which fits exactly the prepared
root the caps having ordinarily a central pin to fit the hole formed in the nervo
cavity, but if a cap without a centre pin is used then the drilled nerve cavity
should be filled with some suitable filling upon this cap which is the support
for the artificial a tooth suitable mineral or other tooth is fixed in any usual
manner.
Having thus described the nature of the invention I will proceed to describo
more fully the manner of performing the same.
After the decayed crown of the tooth is cut off and the nerve destroyed tho
nerve cavity is drilled out and enlarged. Figures 1 shew a side view and end
view of a drill A suitable for drilling out the cavity. Figures 2 shew two sido
elevations of a drill or instrument B for enlarging the cavity to exact standard
size. The upper surface of the root is next bevelled at a right angle to the nerve
cavity by means of the instrument C shewn in side view and end view at Figures 3.
The cutting surface is a flat serrated surface with a pin projecting from it at the
centre. The pin passes into and fits the cavity in the tooth and keeps the cutting
surface always in a plane at right angles to the cavity. When the upper surface
of the tooth root has been bevelled the outer part of the root is cut to fit the
circular cap of gold or other metal E which is to carry the artificial tooth.
A trephining instrument D shewn in side view and section at Figures 4 is used
for this purpose. The instrument has a central peg to enter the cavity in tho
tooth root to guide the instrument in its action and keep the cutting cylinder
concentric with the cavity.
Figures 5 shew a side view and section of one of the caps E upon which the
mineral teeth are to be mounted.
These metal caps are made in any desired number of different sizes to fit
different sized roots and are marked with numbers according to their size,-the
series of instruments used for preparing the tooth root are also correspondingly
inade in different sizes and all the instruments in a series are marked with a
number corresponding to the number on the cap used with that series of
instruments. For example a metal cap marked No. 1 will fit exactly a tooth
root prepared by instruments marked No. 1 and so on with all the other numbers.
After the root has been prepared to receive the metal cap an exact impression of
the mouth must be taken and in order to shew the exact position of the root and
the inclination of the nerve cavity one end of a piece of wire about three quarters
of an inch long must be put in the root leaving the remainder to project, an
impression tray is then taken having a space cut out in the bottom as shewn in
the plan view of a tray at Figure 6 for the pin to pass through.
In this way
when taking the impression the portion of the pin projecting from the root gets
embedded in the wax or plastic material used. When the impression is removed
from the mouth the pin comes away with it and shews the exact position of the
nerve cavity in the root.
Upon the portion of the pin which before entered the nerve cavity in the tooth
root and which now projects from the wax impression a counter part F Figures 7,
in brass of the shaped portion of the tooth root is placed. A number of such
counterparts of the shaped roots of different sizes are provided and they aro
numbered to correspond with the numbers of the caps and the numbers of the
drilling instruments used for shaping that particular size of root.
Each counterpart of a shaped root is formed with a grooved stem as shewn
(Figures 7) When a counterpart of the shaped root has been placed upon the pin
projecting from the wax impression plaster is poured onto the impression and the
brass counterpart of the root gets embedded in the plaster as shewn in that Figure,
and occupies in the model exactly the same position that the real tooth root does

page_text: in the mouth the plaster fills the groove in the stem of the counterpart of the
root and so the counterpart gets firmly held in the plaster.
The metal cap is then placed on to tho top of the counterpart root, the plaster
around the upper part of the root being removed by the tool D if necessary.
The mineral or other tooth of suitable form can now be adjusted to the cap and
afterwards be secured to it in any of the usual ways in which mineral or other
teeth are secured to a metal base.
When this has been finished and the cap with the tooth upon it is placed onto
the previously prepared tooth root it will be found to occupy its proper and
exact position and will hold securely to the tooth root the cap being made to fit
sufficiently tightly to secure this. Figure 8 shews a tooth root with a mineral
tooth secured to it in the manner above described.
Having thus described the nature of the invention and the manner of performing
the same I would have it understood that I claim :-
First. The process substantially as herein described of securing an artificial tooth
to a natural tooth root consisting in.
1. Drilling a cavity down the tooth root to a standard size.
2. Reducing the upper surface of the root to a flat surface at right angles to tho
cavity.
3. Reducing the exterior of the upper part of the root to a cylindrical form of
standard size concentric with the central cavity.
4. Applying a cap of standard sizo to the prepared upper part of the root to
carry the artificial tooth or crown.
Second. The cylindrical cap with its central projecting peg to enter a cavity
prepared to receive it in a tooth root.
Third. The instrument for reducing the upper part of a tooth root to a plane
at right angles to a cavity previously drilled in the tooth root.
Fourth. The instrument for reducing the upper part of a tooth root to a
cylindrical form concentric with a cavity previously formed in the tooth root.
Fifth. The process substantially as herein described for fitting artificial teeth.
In witness whereof I the said Edward Reading have hereunto set my
hand and seal this second day of November in the year of our Lord One
thousand eight hundred and eighty two.