US2437943A - Pontic tooth - Google Patents

Description

March 16, 1948. .LB; EARMAN PONTIC TOOTH Filed June 29, 1945 EAR/WAN Patented Mar. 16, 1948 UNITED STATES PATENT v OFFICE 3 Claims.

This invention relates to a construction of a pontic designed to replace a natural tooth, and more especially to an assembly of this type in which the artificial tooth is provided with a pin by which it is attached to a metallic backing forming a part of the bridgework.

One of the objects of the present invention is to provide a ponticof the type described in which the pin is fused to the center of the tooth and protrudes at an angle to the center axis of the tooth.

Another object of the present invention is to provide a pontic of the type described in which the pin extends lingually at an angle to the tooth and fits a tube which is attached to a metallic backing.

A further object of the present invention is to provide a pontic structure of the type described in which all of the parts are interchangeable and in which the artificial tooth may be easily attached to the metallic backing and replaced if it becomes necessary.

With these and other objects in view which may be instant to my improvements, the invention consists in the procedural steps and the parts and combinations hereinafter set forth and claimed with the understanding that the necessary elements comprising the invention and the procedural steps of its construction may be varied by those skilled in the art without departing from the spirit of the invention or the scope of the appended claims.

Broadly the invention embraces providing a pontic the parts of which are interchangeable and which is constructed so that the artificial tooth can be readily replaced. The pontic assembly comprises an artificial tooth secured to a metallic backing by means of a single pin. The pin is fused to the center of the tooth near its longitudinal axis and protrudes from the posterior surface thereof at an angle to the center axis. This construction greatly strengthens the assembled pontic. The pin is designed to fit within a tube which forms a part of the metallic backing. This arrangement enables the tooth to be readily attached to the bridgework and removed if necessary.

In the drawings:

Figure 1 is a side view in elevation of an 'artificial tooth and a metallic plate showing the pin and tube in broken lines.

Figure 2 is a posterior view in elevation of the structure shown in Figure 1.

Figure 3 is a view in longitudinal section of the tooth shown in Figure 1.

Figure 4 is a view in longitudinal section of the metallic plate shown in' Figure 1.

Figure 5 is a front elevational view of the plate shown in Figure 1.

Figure 6 is a side view in elevation of a tooth and metallic plate, showing the pin and tube in dotted lines, the backing terminating short of the biting edge of the tooth.

Referring more particularly to the drawings, there is illustrated in Figures 1 through 5, a pontic in which the metal plate extends to the biting edge of the tooth. The arrangement shown in Figure 6 is identical in structure with the exception that the metal plate does not extend to the biting edge of the tooth.

In the drawings, numeral I designates an artificial tooth which is cut away to provide a sloping shoulder 2 which overhan s a flat posterior face surface 3. The tooth may be made of porcelain or any other suitable plastic.

The tooth is provided with a headed pin 4, the headof which is fused to the tooth near its center axis to provide additional strength. This positioning eliminates the necessity of additional pins. The pin 4 protrudes from the posterior surface 3 of the tooth at an angle to the central axis of the tooth.

The pin 4 is designed to secure the tooth to a metallic backing which forms a part of the bridgework. This backing may consist of a metal plate 5 which is supplied to the practitioner with the tooth I. This plate 5 is in the form of an angle bracket designed to fit the shoulder 2 and the posterior surface 3 of the tooth I. with an open tube 6 which is fused to the upper surface of the arm 1 of the plate 5 and communicates with an opening in the remaining arm 8.

In attaching the tooth l to the bridgework, the plate 5 is fitted against the tooth l by inserting the pin 4 into the tube 6. Wax is then flowed around the tube and plate to obtain an impression for the backing. After the wax has hardened the plate is removed from the tooth and a carbon pin is inserted into the tube 6. The impression is then invested and the wax removed by heat in accordance with the usual practice. The metallic backing may then be cast or soldered.

After casting, the carbon point is removed by passing a dental fissure burr through the tube and the casting is polished. In this manner a perfect alignment of the pin 4 and tube 8 can be obtained and the parts may then be cemented together.

Preferably the plate 5 as well as the tooth I is supplied the practitioner. However, the plate It is provided 3 may be omitted if desired. In this procedure the tube 6 is fitted over the pin 4 and the wax is flowed around the tube in taking the impression. The previously mentioned lasting procedure is then followed. As a result, the tube forms a part of the metallic casting.

In the event that the tooth should break, it can be more readily and accurately replaced than in the constructions hitherto known. In the event. of breakage, the head of the pin. 4' will be exposed and it is only necessary to fasten a post puller to the pin and turn the lever screw to remove the pin from the tube 6. When this operation has been completed, any remaining portions of the tooth will fall off and a new tooth of the same color and size as originally used may be cemented to the metal in the manner pre viously described. Any excess cement will extrude from the open end of the tube 6 and can be removed.

While I have shown for purposes of illustration, the application. of the invention to an incisor tooth, it is obvious that the same design can be used for the bicuspid and molar teeth. Moreover, it is understood.- that various changes known to the art may be made in the procedure of assembling the. pontic without departing from the spirit of the present invention.

I claim:

1. A dental pontic comprising an artificial tooth, a pin the. head of which is fused to the center of the. tooth. on. the lower half of the longitudinal axis thereof, a backing to fit a portion of the posterior. surface of the tooth and a tube open at both ends secured to said backing to form a rigid support therewith for. said tooth, said pin protruding fromthe. posterior surface of the tooth at. an acute angle to the upper half of the longitudinal. axis for. insertion into the open tube to whichit is cemented for securing the tooth to the backing.

2. A dental pontic comprising an artificial tooth, a pin the head of which is fused to the center of the tooth on the lower half of the longitudinal axis thereof, a metallic plate to fit a portion of the posterior surface of the tooth and a tube open at both ends fastened to said plate to form a rigid support therewith for said tooth, said pin protruding from the posterior surface of the tooth at an acute angle to the upper half of the longitudinal axis for insertion into the open tubeto which it isacementedifor.securing the tooth to the plate;

3. A dental pontic comprising an artificial tooth having a posterior surface cut to form a shoulder adjacent the root of the tooth, an angle bracket plate shaped to fit in the said recess against. the; said posterior surfaces of the tooth, a pin the head of. which is fused to the center of the tooth on thelower half of the longitudinal axis thereof, a tube open at both ends fastened to the outer surface of the portion of the plate which fits. against the shoulder portion of the tooth and forming a rigid. support; with said plate. for said, tooth, said tube communicating withan aperture. in. the remaining portion of the plate, and said pin. protruding from the. posterior surface of' the tooth. at an..acute angle to the upper half. of the longitudinal axis for insertion into the open tube to which it. is cemented for securing the tooth to the plate.

JOHN B. EAR/MAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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