US1879419A - Artificial teeth - Google Patents

Description

Sept. 27, 1932.

s. MYERSON ET AL 1,879,419

ARTIFICIAL TEETH Filed Aug. 15, 1950 Patented Sept. 27, 1932 UNITED STATES PATENT OFFICE SIMON MYERSON, OF BROOKLINE, AND EDMUND A. JONES, OF MEDFORD, MASSACHU- SETTS, ASSIGNORS TO THE IDEAL TOOTH INCORPORATED, OF CAMBRIDGE, MASSA- CHUSETTS, A CORPORATION OF MASSACHUSETTS ARTIFICIAL TEETH Application filed August 15, 1930. Serial No. 475,442.

[fl ing surfaces thereon.

In the present forms of teeth the interdigitating cusps tend to trip up the denture or to exert lateral stresses on the tissues or abutments if there be abutments in place, and

also to exert undue pressure on such tissues or abutments.

Our invention greatly decreases thelateral stresses above referred to by eliminatmg the interlocking cusps and constructing fiat hearing surfaces upon the occlusal surface and said bearing surfaces being substantially in the same plane and cutting cusps flush with the bearing faces. In our constructlon the bearing surfaces are separated by depressions or clearances and preferably at the location of fissures in natural teeth, thus retaining to a great extent the natural appearance of teeth. The teeth so constructed penetrate W the food easily and are adapted to mill it as well as to cut it with a minimum of stress and traumor to the supporting tissues. These and other objects will appear more clearly hereafter.

Of the accompanying drawings:

Figure 1 represents the posteriors on the right side of an upper and lower pair of dentures in occlusion.

Figure 2 represents a mesio-bucco-occlusal view of an upper molar made in accordance with this invention.

Fi ure 3 represents a mesio-bucco-occlusal a lower molar.

Figure 4; represents a bucco-lingual section of an upper and lower molar in occlusion at XY of Figure 1.

. Figure 5 represents a mesial-occlusal perspective view of a bicuspid.

Figure 6 is a view similar to Flgure 5 with the tooth more nearly vertical in position.

Figure 7 is a mes-io-bucco-occlusal view of an upper molar showing a modified form of this invention.

Figure 8 is a mesio-bucco-occlusal view of a lower molar showing a modification similar to that shown in Figure 7.

The same reference characters designate similar structures throughout.

Referring now to Figure 1,1 is an upper first molar, 2 an upper 2nd molar, 3 an upper first bicuspid and 4 an upper 2nd bicuspid, and 5 is a lower first molar, and 6 a lower second molar, 7 a lower first blcuspid, and 8 a lower second bicuspid. The arrow D points to the distal and the arrow M toward the mesial of the dentures.

Referring to Figure 2, 10 designates the buccal, 11 the lingual, 13 the mesial and 12 the distal faces respectively of the upper molar tooth. 14 is a bearing surface, 15 and 16 are the cutting margins of wedge shaped cutting cusps substantially flush with the bearing face 14. 17 is an indentation on lingual face of the tooth extending onto the occlusal.

In Figure 3, 15A and 16A are the cutting margins of the wedge shaped cusps of the lower molar tooth shown'and are similar to 15 and 16 of Figure 2, and 1 1A represents a bearing face similar to that designated by 14. in Figure 2.

In Figure 4 the buccal face .10 of the upper tooth is shown in normal relation to the buccal face 10 of the lower and the bearing faces 1 1 and 14A in occlusion and the cutting margin 15 and 15A are in opposition. The dotted lines 19 and 19A designate the deep margins of the wedge shaped cutting cusps shown in Figures 2 and 3 and all other figures.

In the bicuspid shown in Figure 5, 18 designates depressed portions or interruptions of the base surface 14. Similarly 18A designates depressions in the base surface 14A Figure 6.

In Figure 7, 17 and 20 are also depressions or interruptions of the base surface, and 21 is the cutting edge of a wedge shaped cut ting cusps substantially flush with 14 and directed diagonally across the occlusal surface.

In Figure 8, 17A is an interruption of the base surface 14A. 21A is a diagonally directed cutting cusp flush with 14A and 19 is the bottom of a fissure positioned along the bucco distal aspect of the said cusp.

It will be seen from the foregoing that when ing with said bearing faces and clearlng the opposing teeth of dentures made in accordance with our invention are articulated that the base surfaces of the lower slide from side to side or in a rotary direction without interference from the cutting cusps and that the cutting cusps when brought into opposition will cut through the food very readily. Moreover in rotary or side to side motion the food will be cut and ground as the sharp edges pass each other or as they pass over the flat bearing surfaces. Also that the opposlng bearing surfaces will mill the food and that the gateways provided operate to prevent clogging and thus the stress upon the supporting tissues is greatly relieved.

In the form shown in Figure 7 and Figure 8 the long oblique cutting cusps are preferably in opposition lengthwise when the upper and lower teeth are in normal occlusion, and that the cutting cusps will pass each in a very efiicacious manner for cutting and milling during the movements'of articulation.

It is of course possible to have various positions and design of base surfaces and cutting cusps and means of gateways without departing from the spirit of this invention. Nor do we limit our invention to artificial teeth for that class of restoration commonly called plates but include bridge work as well.

What we claim is:

1. An artificial tooth having bearing surfaces and cutting cusps on its occlusal aspect lying in the same plane, the external edge of the cutting cusps being substantially flush with said bearing faces, and grooves to clear the masticated food from the occlusal face of the tooth.

2. Artificial tooth having its buccal and lingual cusps flattened to form bearing surfaces and wedge shaped cutters extending between said flattened cusps, the cutting margin being substantially flush with the flattened cusps and clearing grooves to clear the masticated food from the occlusal face.

3. An artificial tooth having flat bearing surfaces in the position of the normal cusps,

transverse wedge shaped cutters between the buccal and lingual cusps, grooves on the occlusal face adjacent the wedge cutters and communicating to the other face of the tooth.

4. An artificial tooth having fiat bear in surfaces on its occlusal face, wedge shaped cutters extending between the flat bearing surfaces, the cutting margins being substantially flush with the flat bearing surfaces and the said cutting margin being longer than the base of the cutting cusps and clearance grooves adjacent the bearing'fac'es and the cutting cusps.

5. An artificial tooth having flattened buc- ,cal and lingual cusps forming bearing faces on its occlusal face in the same plane and cutting cusps between said flat bearing faces, the cutting margins of said cutting cusps merggrooves adjacent the cutting cusps.

6. An artificial tooth having fiat bearing faces on its occlusal face and cutting cusps between said flat bearing faces, the cutting 1 margins of said cutting cusps merging with said bearing faces and clearing grooves adjacent the cutting cusps, the cutting cusps being obliquely directed across the occlusal surface of the said tooth.

In testimony whereof, we have hereunto atfixed our signatures.

SIMON MYERSON. EDMUND A. JONES.

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