Improvements in Crowning Appliances for Dentists.
Year: 1895

page_text: Date of Application, 28th Aug., 1895
Complete Specification Left. 10th Apr., 1896-Accepted, 6th June, 1896
PROVISIONAL SPECIFICATION.
Improvements in Crowning Appliances for Dentists.
We CLAUDIUS ASH & SONS LIMITED whose Registered Office is No. 9 Broad
Street Golden Square in the County of London Manufacturers of Dentists'
Materials and ROBERT PROUDFOOT LENNOX of No. 82 Norwich Street
Cambridge in the County of Cambridge Dentist do hereby declare the nature
of this invention to be as follows :-
:-
The object of our invention is to construct and arrange a set of appliances
whereby a dentist may obtain by a more improved process a better impression of
the face of the root of the tooth or teeth which is or are required to be crowned.
Figure 1. in the accompanying drawing shows a form of a steel rod with a
moveable cylinder A. The tooth requiring to be crowned is first cut off and the
root canal is enlarged to receive the instrument shown in Figure 1. by which. the
depth is measured and registered by cylinder A.
Figure 2. is a steel rod with a moveable roughened cylinder B capable of being
fixed in any position.
After the correct depth of the cavity has been ascertained by Figure 1. then the
cylinder on the instrument shown in Figure 2 is placed in the same position as that
on Figure 1. and the instrument shown in Figure 2 with the cylinder thus fixed is
inserted in the orifice of Figure 3. (hereinafter described which is then filled with wax.
composition) and inserted in the root-canal for the purpose of obtaining a correct
impression of the face of the root of the excised tooth.
Figure 3. is a small conical cup with an orifice at the apex and a scalloped magin
whereby when filled with wax composition and pressed over the root to be crowned
a sharp impression of the root-face and the direction of the root-canal are:obtained
and such impression is preserved from damage in process of removal from the mouth
by means of Figure 4 (hereinafter described).
Figure 4. is a dental-impression-tray with a slot C running round the bottom of
its outer margin. It is filled with wax composition and Figure 2, having Figure-3
fixed outo its top as aforesaid is passed through the slot C, of Figure 4 and kept
in position there by the wax composition, so that on the whole apparatus being
placed in the patient's mouth, on his closing his teeth, the impression of the root to
be crowned will be made on the wax composition in Figure 3 and the impression
of the other teeth on the wax composition in Figure.4.
:
Improvements in Crowning Appliances for Dentists.
We CLAUDIUS ASH & SONS LIMITED whose Registered Office is No. 9 Broad
Street Golden Square in the County of London Manufacturers of Dentists'
Materials and ROBERT PROUDFOOT LENNOX of No. 82 Norwich Street
Cambridge in the County of Cambridge Dentist do hereby declare the nature of
PriQd27

page_text: this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
And we beg leave to refer to the drawings filed with our Provisional Specification
dated the 28th day of March 1895 No. 16141 :-
The object of our invention is to construct and arrange a set of appliances
whereby a dentist may obtain by a more improved process a better impression of
the face of the root of the tooth or teeth which is or are to be crowned.
Figure 1. in the drawing filed with our Provisional Specification shows a form
of a steel rod with a movable cylinder A. The tooth requiring to be crowned, is
first cut off and the root-canal is enlarged to receive the instrument shewn in
Figure 1 by which the depth of the canal is measured and registered by cylinder A.
Figure 2. is a steel rod with a movable roughened cylinder B, capable of being
fixed on any part of the rod. This rod and cylinder are used as hereinafter
described.
Figure 3. is a small conical cup with an orifice at the apex and a scalloped margin.
This cup is filled with wax composition and the steel rod Figure 2 is passed partially
through it. The steel rod is then inserted in the root-canal and on the cup being
pressed against the root a sharp impression of the root-face and the direction of the
root-canal are obtained. The cup and steel rod are then removed from the
mouth and after the surplus wax composition has been trimmed off they are
replaced.
Figure 4. is a dental impression-tray with a slot C. running round the bottom of
its outer margin. It is filled with wax composition and when a general impression
of the teeth is taken by it, the steel rod, Figure 2, is made to strike the centre of
the wax composition in a direction towards the front of the tray which then guides
it unerringly through the slot. After the impression has been cooled in the mouth
by means of a syringeful of water the steel rod, Figure 2, is withdrawn; then the
impression-tray Figure 4, is also withdrawn and brings away with it the conical cup
Figure 3. The steel rod Figure 2 is then replaced in the impression and secured
to the outside of the tray Figure 4 by being touched with wax. Cylinder B, is
placed on the end of the steel rod Figure 2, which is to enter the plaster model, the
model is cast, the steel rod is withdrawn and the roughened cylinder remains behind
in the model and forms an indestructible reproduction of the root-canal which thus
permits of the crown being prepared and adjusted ready for insertion in the mouth
of the patient.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is-
The construction and arrangement of our improved crowning appliances
substantially as herein described and illustrated in Figures 1, to 4 of the
drawing filed with the Provisional Specification.