IMPROVEMENTS IN TAKING IMPRESSIONS OR CASTS OF THE MOUTH FOR USE IN MAKING ARTIFICIAL TEETH, AND IN APPARATUS FOR THE SAME AND OTHER DENTAL OPERATIONS."
Year: 1876

page_text: LETTERS PATENT to John Wood, of Dumfries, in the County of Dumfries,
North Britain, Surgeon Dentist, for the Invention of "IMPROVEMENTS IN
TAKING IMPRESSIONS OR CASTS OF THE MOUTH FOR USE IN MAKING
ARTIFICIAL TEETH, AND IN APPARATUS FOR THE SAME AND OTHER DENTAL
OPERATIONS."
PROVISIONAL SPECIFICATION left by the said John Wood at the Office
of the Commissioners of Patents on the 15th November 1876.
JOHN WOOD, of Dumfries, in the County of Dumfries, North Britain, Surgeon
Dentist. "IMPROVEMENTS IN TAKING IMPRESSIONS OR CASTS OF THE MOUTH FOR
USE IN MAKING ARTIFICIAL TEETH, AND IN APPARATUS FOR THE SAME AND
OTHER DENTAL OPERATIONS."
This Invention relates principally to the taking of impressions or casts of the
mouth for use in the construction of artificial teeth, and comprises the application
of a regulated jet of water or other suitable cooling agent to the plastic material or
compound used for the purpose whereby such material is at once rendered hard
and is thereby prevented from being altered in form or shape when being removed
from the mouth.
The Invention also comprises improved apparatus for obtaining the jet of
water or other suitable cooling agent, which apparatus is also applicable to other
dental operations.
In taking the impression a quantity of beeswax or other suitable material or
compound is rendered soft and plastic by heat; it is then applied to the mouth by
means of a tray or impression cup, and an impression of the teeth, gums, and palate
is taken. Hitherto the cast has been removed from the mouth while still in a com-
paratively soft state and has thus been liable to a change of shape which renders
the model untrue and imperfect.

page_text: In carrying out the Invention an impression is taken in the usual manner, but
instead of removing the cast in a soft state it is subjected to a jet of water or other
suitable cooling agent whilst still held steadily in position in the mouth. The wax
or other modelling material is thus at once rendered hard and its liability to altera-
tion in shape prevented and the accuracy of the impression thereby secured.
The apparatus for obtaining the jet may be constructed with a hollow wooden
case in the form of an ordinary dentist's spitoon pedestal having a movable top
which can be used as an operating table. A closed metal tank or reservoir is sup-
ported in the upper part of the interior of the wooden case and has a small cylindrical
recess in its top which may be used as an ice chamber or to hold a spitoon.
Foot bellows connected with a rubber ball or chamber fitted with a valve to
prevent the return of air into the bellows is placed in the lower part of the case and
connected by means of a pipe with the tank. The action of the bellows fills the
rubber ball or chamber and causes it to expand, and it by its clastic contractile
tendency maintains a continuous flow of air into the tank or water reservoir. The
compressed air acting on the surface of the water in the tank causes a uniform
discharge through a flexible outlet pipe fixed to the side and terminating in a
coupling for the attachment of any one of a series of nozzles adapted for varius
cases.
The flexible pipe or nozzle is provided with a stop-cock or valve which can be
controlled by the thumb or finger of the hand holding the pipe, so that the other
hand is at liberty for manipulating the impression or cast.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Wood in the Great Seal Patent Office on the 11th May
1877.
JOHN WOOD, of Dumfries, in the County of Dumfries, North Britain, Surgeon
Dentist. "IMPROVEMENTS IN TAKING IMPRESSIONS OR CASTS OF THE MOUTH FOR
USE IN MAKING ARTIFICIAL TEETH, AND IN APPARATUS FOR THE SAME AND
OTHER DENTAL OPERATIONS."
My said Invention relates principally to the taking of impressions or casts of the
mouth for use in the construction of artificial teeth, and comprises the application of
a regulated jet of water or other suitable cooling agent to the plastic material or
compound used for this purpose whereby such material is at once rendered hard, and
is thereby prevented from being altered in form or shape when being removed from
the mouth.
My said Invention also comprises improved apparatus for obtaining the jet of
water or other suitable cooling agent, which apparatus is also applicable to other
dental operations.
In taking an impression or cast of the mouth a quantity of beeswax or other
suitable material or compound is rendered sufficiently soft or plastic by heat; it is
then applied to the mouth by means of a tray or impression cup and an impression
of the teeth, gums, and palate is taken. Hitherto the cast has been removed from
the mouth while still in a comparatively soft state, and has thus been liable to a
change of shape which renders it as a model untrue and imperfect.
In carrying out my said Invention an impression is taken in the usual manner,
but instead of removing the cast in a soft state it is subjected to a jet of water or
other suitable cooling agent whilst still held steadily in position in the mouth. The
wax or other modelling material is thus by means of the jet at once rendered hard
and its liability to alteration in shape is prevented, great accuracy in the impression
being thereby secured..

page_text: My improved system of cooling and hardening the plastic material in sitú is also
obviously applicable in taking what is known as a
"bite' or any other impression
or cast from the mouth.
In the jet producing apparatus, which I prefer to use in carrying out my Inven-
tion, the pressure is obtained by means of a foot bellows, the air from which is led
to the top of a closed vessel or reservoir into which the water or other cooling
liquid is put. The pressure of the air on the liquid forces it up a dipping pipe end
by a flexible tube to a suitable nozzle fitted with a stop-cock.
A convenient and preferable modification of my improved jet-producing apparatus
is represented in the accompanying Sheet of explanatory Drawings, Figure 1 being
a side elevation, and Figure 2 a vertical section as at right angles to Figure 1, whilst
Figure 3 is an enlarged section of the stop-cock employed. In these Figures the
same reference numerals are used to mark the same or like parts wherever they are
repeated.
The apparatus shown in the Drawings comprises a hollow wooden case 4 which
is in the form of an ordinary dentist's spitoon pedestal, and is fitted with a sliding
or otherwise movable top 5 which can be used as an operating table. A closed
metal tank or reservoir 6 is supported in the upper part of the interior of the
wooden case or pedestal 4 and is made with a cylindrical recess & dipping down
from its top and which may be used as an ice chamber or to hold a spitoon 9. The
lower part of the pedestal or case 4 is fitted with a door 10 which on being opened
gives access to a foot bellows 11 which has its inlet valve in its bottom and an out-
let in its top, the latter communicating by a flexible pipe 12 with a hollow rubber
ball or bag 13. This rubber bag 13 is fitted with a check valve at its inlet, and
being expanded by the air blown into it its elasticity maintains a sufficient regular
pressure notwithstanding the intermittent action of the bellows 11. The bag or
elastic chamber 13 is connected by a flexible pipe 14 to a metal pipe 15, which for
convenience passes through the bottom of the water reservoir 6 and is continued
inside it to its upper part as indicated by dotted lines, so that the air compressed by
the bellows 11 may press on the surface of the water in the reservoir G. A screw
plug 16 made tight by a rubber washer is fitted to the top of the reservoir 6 for
filling it by, and the reservoir 6 is fitted with a pipe 17 for the egress of the water,
this pipe 17 dipping down inside to near the bottom of the reservoir and having
attached to it outside a flexible pipe 18 which connects it to the stop-cock 19 and
nozzle 20. The stop-cock comprises an inlet piece 21, a body piece 22, and a
cover 23, all screwed together with interposed rubber washers, and the body piece 22
being formed with an outlet tube 24 to which the nozzle 20 is attached. The valve
or closing detail is a disc 25 fixed on a spindle 26 which passes through the cover 23
and has a button 27 fixed to its outer end to be pressed on by the thumb or finger.
The valve 25 is opened by pressing the button 27 inwards, and closes against a seat
formed on a tubular part of the body piece 22 which projects into the inlet piece 21,
the closing of the valve being insured and rendered automatic by a spiral spring
placed inside the body piece 22. Different nozzles (20) adapted for various cases
may be provided for being attached as required to the stop-cock. The nozzle 20
and stop-cock 19 can be quite conveniently held and controlled by one hand, so that
the other hand is at liberty for manipulating the impression or cast.
Having thus particularly described my said Invention and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise details
herein described or delineated, but that what I believe to be novel and original, and
claim as the Invention secured to me by the herein-before in part recited Letters
Patent is,
1. The using of a jet of water or other suitable cooling agent for hardening an
impression or cast of the mouth taken for dental purposes whilst the impression or
cast is still in the mouth, substantially as herein-before described.
2. The combination of the bellows, the reservoir for water or other liquid, and
the nozzle, all arranged and acting, substantially as and for the purposes herein-
before described.

page_text: 3. The combination of the jet producing apparatus with the spitoon receptacle
and pedestal, as herein-before described.
In witness whereof, I, the said John Wood, have hereunto set my hand and
seal, this Tenth day of May, in the year of our Lord One thousand eight
hundred and seventy-seven.
JOHN WOOD. (L.S.)