US2301825A - Artificial tooth - Google Patents

Description

1942. M. R. STEIN ETAL ARTIFICIAL TOOTH Filed NOV. 27, 1941 MICHAEL RuSsELL S-rsm F adsEPH KOHN war-W Patented Nov. 10, 1942 ARTIFICIAL TOOTH Michael Russell Stein, New York, N. Y., and

Joseph Kohn, Merion, Pa., assignors to Universal Dental Company, Philadelphia, Pa., a corporation of Pennsylvania Application November 27, 1941, Serial No. 420,628

6 Claims.

This invention relates generally to artificial teeth and more particularly to an improved construction of anterior tooth of the type adapted for mounting in a denture.

Among the principal objects of the present invention is to provide an artificial anterior tooth which simulates the natural tooth in appearance and feeling to the tongue; which is adapted to be mounted upon the denture without the use of the conventional anchoring pins or the like; which is simple and inexpensive in construction; and 'which is capable of being variously positioned upon the denture to suit individual requirements, all without reducing the strength of the union between the tooth and the denture ture in which it is mounted, but also to they.

other teeth of the denture. The present invention enables these changes in relative position of the teeth in the denture to be effected without rendering the denture base material visible at the proximalsides of the teeth and thus provides for overlapping of adjoining teeth ina manner and to a degree not heretofore possible.

A still further object is to provide a tooth of the character hereinbefore described'which not only has the attribute of being individually capable of angular adjustment relatively to its vertical axis without revealing the denture base material at the proximal sides of adjoining teeth, but which also has the capability of being adjusted vertically by the simple expedient of grinding the lap face thereof to vary its effective length. Thus, the artificial teeth constructed in accordance with the principles of the present invention may be readily altered to adapt them to fit greater or lesser intermaxillary openings;

Briefly stated, it is a general object of the present invention to provide an artificial anterior tooth with grooves or recesses in the mesial and distal faces thereof which are so formed as to readily receive the denture base material in the manufacture of the denture to insure an exceedingly strong union between the tooth and the denture base material irrespective :of the mounting position assumed by the individual visible when viewed from the labial side thereof, the said grooves or recesses being further so shaped and disposed as to permit the lap face of the tooth to be ground as the exigencies of an individual case may require without impairing the eflicacy of said grooves or recesses for retaining the tooth in the denture base material.

Other objects and advantages of the invention will appear more fully hereinafter, it being understood that the present invention consists substantially in the combination, construction,

location and relative arrangement of parts as described in detail hereinafter, as shown in the accompanying drawing and as finally pointed out in the appended claims.

In the accompanying drawing, which is illustrative of the present invention:

Figure l is a front perspective view of a tooth constructed in accordance with and embodying the principles of the present invention;

Figure 2 is a rear perspective view of the tooth;

Figure 3 is a side elevational view thereof;

Figure 4 is a vertical cross-sectional view taken on the line 4-4 of Figure 2;

Figure 5 is a horizontal cross-sectional view taken on the line 5-5 of Figure 3;

Figure 6 is an enlarged side elevational view similar to Figure 3 illustrating the adaptability of the lap face thereof to be ground down as desired;

Figure 7 is a horizontal cross-sectional view of a denture composed of the six anterior teeth of the present invention arranged in a more or less normal relation;

Figure 8 is a horizontal cross-sectional view of denture similar to that of Figure 7 but illustrating the teeth individually arranged in positions different from the normal positions of Figure 7; and

Figure 9 is a vertical section through a denture showing one of the teeth mounted therein.

Referring now to the drawing and more particularly to Figures 1 to 6 thereof which show an artificial anterior tooth constructed in accordance with the present invention, it will be observed that the front or labial surface I 0 of the tooth extends from the incisal edge ii thereof upwardly to the cervical line I! which serves as the line of demarcation between the exposed labial surface of the tooth and the adjoining portion of the denture plate in which the tooth is mounted, this denture plate being shown in Figures 7 and 8 wherein it is designated generally by the reference numeral I 3. Extending tooth, all without renderingthe base material -55 upwardly beyond the cervical line I2 is the cervical flange or collar 14 of the tooth which is adapted to be embedded in the base material of the denture plate approximately to the depth of the cervical line [2.

The rear or lingual face l5 of the tooth extends upwardly from the incisal edge II thereof and is shaped to follow generally the contour of the corresponding surface of a natural tooth, the up per edge of this lingual surface being merged into the cervical portion [6 of the tooth below the lap face ll thereof. It will be understood, of course, that the lap face If is contoured in general correspondence with the contour of that portion of tional pin type tooth in that the lingual surface [5 thereof is provided with a longer upward sweep from the incisal edge I l, thereby-more closely simulating the contour of the lingual surface of the natural anterior tooth. This becomes possible in the tooth of the present invention because the absence of any anchoring pins in the lingual surface thereof dispenses with the necessity of providing the tooth with the transversely extending rib generally present in the pin type tooth.

Formed in each proximal face of the tooth is an elongated, substantially vertically extending groove I9 of generally T-shaped cross-section. Thesegrooves l9l9 extend from the lap face I! of the tooth downwardly to points located approximately midway between the lap face and the incisal edge of the tooth, the lower extremities of the grooves being located approximately centrally between the lingual and labial surfaces of the tooth. While these grooves I9I9 may be of uniform cross-section. from top to bottom thereof, it is preferred to form them of gradually reduced cross-section toward their lower extremities in order to conform them with the correspondingly tapered cross-section of the tooth and so provide maximum tooth body material to either side of each groove. The grooves are relatively so arranged that the enlarged portions thereof are located well within the body of the tooth, while the restricted portions. thereof open into the proximal faces of the tooth.

An important characteristic of the tooth of the present invention is that the grooves |9-| 9 formed in the proximal faces thereof are asymmetrically located w i respect to the mesio-distal plane extending vertically through the incisal edge of the tooth, this plans being designated in Figures 4, 5 and 6 by the line '28. In each case, thegroove l9=- in the distal face of the tooth is located closer to the said mesio-distal plane than is the groove l9 in the mesial face of the tooth. By reason of this off-set relation of the grooves l9 and l9 in the direction .labio-lingually of the tooth, it becomes possible to arrange each tooth in the denture plate as the exigencies of a particular case may require. This capability of the teeth to be individually arranged in the denture plate is best illustrated in Figures 7 and 8 to which reference is now made.

In Figure'l, a denture is shown wherein the six anterior teeth constructed incaccordance with '75 and embodying the principles of the present invention are relatively arranged in more or less normal relation. Thus, the several teeth are so disposed in the denture plate l3 that the mesiodistal planes thereof generally extend tangentially to the curvature of the denture plate. In such position, the denture base material commonly enters all of the grooves of the several teeth to securely interlock the same with respect to each other and the denture plate. It will be observed that in this normal position of the teeth as shown in Figure '7, the denture base material designated 2| is not visible between the proximal edges of adjoining teeth when viewed from the front .or labial surface thereof, this being due to the fact that the restricted openings of the grooves are in each case so located rearwardly or lingually of the mesio-distal planes 20 that each pair of adjoining teeth mesh with or contact each other frontally of the grooves and so conceal from frontal view the base material 2! of the denture.

Figure 8 shows a denture wherein the several teeth are differently arranged than as in Figure 7. In this, denture of Figure 8, the teeth are respectively identical with those shown in Figure "7. It will be noted, however, that the central incisors overlap to greater extent in the arrange- .ment of Figure 8 than in that of Figure 7. Also, in Figure 8, the lateral incisors have each been rotated about their vertical axes so that they are differently related to their adjoining central incisors. than in the arrangement of Figure 8. Finally, the cuspids of Figure'B are quite sharply turned to provide a substantial overlap with respect to their adjoining lateral incisors, it being thus apparent that the arrangement of the teeth of Figure .8 substantiallydiffers from the normal arrangement of Figure 7. In spite of this, the contactingsurfaces of the teeth in the denture .of-Figure 8 conceal from frontal view the denture base material 2!. This is due to the fact that the mesialgrooves 19 are in each case located sufficiently .to the rear of the mesio-distal plane of the tooth as to permit the latter to. be rotated about its vertical axis through a substantial are without rendering said groove visible when viewed from the frontal or labial side of the teeth. Thus, by means of the present invention the left anteriors may be rotated in counterclockwise direction about their vertical axes from the positions respectively shown in Figure '7 into the positions as shown in Figure 8, while the right anteriors maybe correspondingly rotated in clockwise direction about their vertical axes from the positions shown in Figure '7 into the positions shown in Figure 8. With the teeth positioned as shownin Figure '7 and in Figure 8, as well as in intermediate (positions, the denture base ,material is at all times concealed from frontal view and yet the teeth in all such cases are strongly joined together and united in the denture plate.

Preferably, the tooth is provided with a transverse passage 22 extending freely between the ,lower extremities of, the proximal grooves l9 and 19*, this passage being in such communication :with the grooves that as the denture base material is introduced into the latter, it also flows freely into the transverse passage to provide for increased :retention in the region of the passage.

Refer-ring nowmore particularly to Figure 6, it .willberobserved that in the tooth of the present zinventionzthe lap face :l'l :thereof may be ground to different contours without materially impairing the retentive properties of the proximal grooves l9 and 19. Thus, the lap face I! may be ground to any of the surfaces designated by the broken lines 23 to provide a mounting face to suit a given individual case. Because of possibility of so grinding the lap face I! of the tooth to vary the gingival curvature of the tooth, the tooth of the present invention is adapted to be variously set in the denture to suit individual requirements. This is illustrated in Figure 9 wherein the dotted lines show a tooth which has been shortened in its effective length by grinding down the lap face ll thereof. Not only may a given tooth be ground in the lap face thereof to shorten its effective length and so adapt it for use in a case where the intermaxillary opening is relatively small, but it also may be so ground as to permit the tooth to be swung about the ridge as a fulcrum to vary its inclination labially or lingually with respect to the perpendicular. Thus, a given tooth of the present invention is adapted to be variously positioned in the denture plate as the individual case may require without impairing its retention in the denture and without rendering visible to frontal view the base material of the denture plate.

It will be understood, of course, that the present invention is susceptible of various changes and modifications which may be made from time to time without departing from the real spirit and general principles thereof and it is accordingly intended to claim the same broadly, as well as specifically, as indicated in the appended claims.

What is claimed as new and useful is:

1. An artificial anterior tooth having lingual and labial surfaces shaped to conform substantially to the contour of such surfaces in natural teeth and a cervical portion having a lap face inclined in labio-lingual direction, said tooth being provided in the proximal surfaces thereof with substantially vertically extending elongated grooves of generally T-shaped cross-section, each of said grooves extending incisally from the lap face of said cervical portion for a distance at least equal to half the length of the tooth measured along its vertical axis, the groove in the mesial face of the tooth being spaced from the mesio-distal plane of the tooth a greater distance than is the groove in the distal face of the tooth.

2. An artificial anterior tooth having lingual and labial surfaces shaped to conform substantially to the contour of such surfaces in natural teeth and a cervical portion having a lap face of generally oval outline, said tooth being provided with elongated grooves in the proximal surfaces thereof, each of which extends incisally from said lap face for a distance at least equal to half the length of the tooth measured along its vertical axis, said grooves being adapted to receive the base material of a denture plate during molding to retain the tooth in said plate, said grooves being offset from one another in a direction labio-lingually of the tooth.

3. An artificial anterior tooth having lingual and labial surfaces shaped to conform substantially to the contour of such surfaces in natural teeth, said tooth being provided with recesses in the proximal faces thereof for receiving the base material of the denture plate in which the tooth is mounted, said recesses being labio-lingually offset from one another to permit the tooth to be variously set in the denture plate to provide for overlapping of adjoining teeth without rendering the denture base material visible between the teeth when viewed from the labial side thereof.

4. An artificial anterior tooth having lingual and labial surfaces shaped to conform substantially to the contour of such surfaces in natural teeth, said tooth being provided with recesses in the proximal faces thereof for receiving the base material of the denture plate in which the tooth is mounted, said recesses being each disposed to the lingual side of the proximal contact lines of the tooth and being labio-lingually offset whereby to permit the tooth to be variously set in the denture plate to provide for overlapping of adjoining teeth Without rendering the denture base material visible between the teeth when viewed from the labial side thereof.

5. In an artificial anterior tooth of the character defined in claim 4 wherein the recess in the distal face of the tooth is closer to the distal contact line than is the recess in the mesial face to the mesial contact line.

6. In an artificial anterior tooth of the character defined in claim 4 wherein said tooth is provided with a lap face which is inclined in labia-lingual direction and in which said recesses terminate, said lap face being adapted to be ground to vary the effective length of the tooth without impairing the capability of said recesses to freely receive the base material of a denture plate during molding and so firmly retain the tooth in said plate.

MICHAEL RUSSELL STEIN. JOSEPH KOHN.

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