US1426114A - Artificial interchangeable tooth - Google Patents

Description

A. SCHWARTZ AND J. WIEDER.

ARTIFICIAL INTERCHANGEABLE TOOTH.

APPLICATION F|LE D DEC. 7, I920.

1,426,1 14. Patent-ed'Aug. 15, 1922.

war

"UNITED STATES PATENT OFFICE.

ABRAHAM CHWARTZ AND JOHN WIEDER, OF BOSTON, MASSACHUSETTS.

ARTIFICIAL INTERGHANGEABLE TOOTH.

Specification of Letters Patent. Patented A 15, 1922.

Application filed December 7, 1920. Serial No. 428,887.

changeable teeth, and more particularly to crowmis quickly and easily detachable asa type thereof wherein a metallic back is permanently fixed to lateral anchorages such as afforded by natural teeth, and with a facing or crown of porcelain or the like constituting the body of the tooth applied'to said metal back in a manner so as to be detachable and interchangeable when required, but with interlocking provision between the metal back and the porcelain crown so constructed as to withstand pressures exerted upon it in alldirections on the occlusion of opposing teeth. A principal ob- .ject of the invention is to provide means whereby the porcelain "crown anchored.

and secured to the metallic backing or base more strongly and securely than has heretofore been possible while at the same time the required for replacement on account of breakage or for other reasons. A further object is to provide an interfitting engagement between the metal back and' the porcelain crown affording an absolutely firm base for the crown whereby any possibility of the crown being crowded back beyond its normal position is prevented and additional strength and support for the porcelain ob tained. In accordance with our invention the cusp and biting surfaces of the tooth are of porcelain instead of metal as is commonly the case with teeth of the present interchangeable type. To these ends we provide a metal base or back of a boxed form affording maximum strength and rigidity,

and having undercut angles or edges with which the porcelain crown has interlocking engagement substantially throughout the extent thereof. A further object is to provide an improved mounting of the porcelain crown upon its metallic base which permits any necessary grinding away of the lnner end of the tooth thus constituted for fitting it in place without weakening or interfering with the interlocking engagement between the porcelain and the metal base. The foregoing and other objects and advantages of the invention will more fully appear from the following detailed description, and the distinctiw features of novelty will be pointed out in the appended claims.

Referring to the drawings;

Figure 1 is a side elevation showingthe I porcelain crown of our invention removed;

Figure 2 is a front view thereof; Figure 3 is an end view looking from the outer. end of the crown; I

Figure 4 is a side view of the metallic base removed;

Figure 5 is a front view thereof;

Figure 6 is an'end view looking from the I inner end thereof;

Figure 7 is'a side view of the porcelain I crown assembled with the metallic base, i. e. the complete tooth;

F gure 8 is a front view thereof; Figure 9 1s a transverse vertlcal. section; and I Figure 10 is a horizontal section on line 10 10 of Fig. 7.

l0 indicates the porcelain crown of the.

invention, the cus portion thereof-being indicated at 10*. his crown is recessedfat its upper portion on its inner side toreceive the metallic backing. In accordance with our invention this recess is approximately L-shaped in transverse section, with the corner angle so thereof however, somewhat acute for a purpose that will be ex- I plained. The crown is rebated at its sides around this recess as indicated at 11 with the rebated edges undercut as indicated at 12. The base ledge or shoulder of this recess is al so rebated around the edge thereof as indicated at 13, this rebate sloping'downward or toward the cusp 10 of the crown as it'extends toward the outer side thereof as indicated at 13*, this slope corresponding generally to the slope indicated at 14, of the base of the crown recess which forms the longitudinal median bore 15 from the inner end thereof, to receive the metallic'pin of the base, this bore opening into the recess at the back of the crown as; indicated at v acute angle 00. The crown is formed with a 15, and extending downward 'or outward of the tooth well toward the end of the cusp as indicated at 15*.

The fixed metallic backing or base for interfitting and interlocking with the "interchangeable crown facing described, comprises an L-shaped plate or web member 16 bearing at its inner-side apin .17, which 'fits into the hole 15. This plate or web-bears at its sides, :flange or cheek portions 18, which extend inwardly and are adapted to fit closely into the undercut rebates 11, at the sides of the crown recess. This metallic backing has its bottom sloped downwardly inward as indicated at 19 to fit thesloping bottom 14, ofthecrown recess'and its curving outer side portion bears a downwardly extendin rim or shroud QO fitting the rebate l3 0 the crown,.the side-portions thereof also sloping downwardly inwardas indicated at 20 to fit'the slopingcontour 13 at the sides of the rebate 13.v With this construction it will be noted that the metallic back is of a boxed form that is stiffened and braced by its several parts in all directions so as to afiord greatest possible strength for a given amount of metal. By reason of-the extended interlocking areas of the porcelain with the metal back the porcelain crown is more firmly held and is less apt tobreak than inany previous. form of artificial interchangeable tooth known to us. The bottom of the back provides a ledge of substantial extent constituting a firm and reliable abutment for the crown preventing any possible chance of the crown being crowded back beyond its normal position as has been :the case with previous types of interchangeable crowns. Itwill also be noted that we :provide strongandreliable .means for interlocking the metallic back with the porcelain facing aroundthe periphery, as well as atthe longitudinal median line of the tooth, this being accomplished by the inturned flanges 18 engaging undercut lateral rebates 11, while the downward slope of the bottom 14, provides an interlocking abutment with the bottom 19 and rim shroud 20 of the metal back further holding the crown facing 10 secure against pulling off from the back, all these interlocking points of engagement being additional and supplementary to the hold obtained. by the pin 17 in the'bore 150f the facing. Thus it is only necessary'to cement or otherwise secure'the porcelain facing to the metal back sufiici ently to prevent displacement of the facing, all tendency to 'may be filled with metal 22 to complete the contour of the tooth and reinforce and stiffen "the '-back. 'This metal back may 'be "formed as usual of gold'or suitable composition'wlhich needn'otbe detailed herein. It

:will be understood that the metal back describedmay be secured to suitable lateral anchorages in uSuaLmanner, indicated at 123.

WV e are aware ithatathe invention may be embodied inother specific forms without de- Qparting from the spirit :Or essential attributes thereof, and we therefore desire the present embodiment :tobe considered in all '1. An artificial tooth comprising a de- .tachable v.and interchangeable porcelain or :like facing-rand a :metalback of boxed form,

said facing having arecess whichs'aid back'is fitted, said s'facingand, said backhaving peripheral portions interlocked ttO pre- 1 vent lateraldisplacementof said facing, and said back presenting a base of substantial dimensionengaginga ledge of said facing.

An .iarti ficial "tooth comprising a deitachable and interchangeable porcelain .or

like facing recessed at the upper portion of the inner-side thereof with undercut rebates around the .side's of said recess, and a metal back of boxed form Tbearing rim portions having'an interlocking fit with; said facing,

and said back presenting a base ofsubstan- 'tialdimension engaging a ledge ofsaid facing.

rebates around the-sides of said recess,and-a metal back'bearing rim POI'UOIIS having an 3. An artificial tooth ,compr'isinga porcellain orlike facingrecessed atcthe upper-portion of the Tinnerside thereof with. undercut interl'ocking fit with said :facing :andfsaid back bearingqa'lso a pin engaging a longitudinal 'medi an hole-ofsaid facing.

4. An artificial tooth comprising a porcelain or like faclng with a recessln its Inner 'upper'port-ion formingan acute angle at its bottomandca 'metaltback'fitted in said recess with itsbottomsloped to fit the-acute angle of said recess, said back bearing alsola pin engagingaklongitudinalmedian hole in said facing.

An artificial tooth comprising a porcelain or likefacing having "a recess in .its inner upper portion formlng an acutezangle at its bottom and with undercut rebates around .the sides-'of'said recess, andaimetalback fitted in said recess with .its bottom in- .terlocking"witht-he bottom thereofand with 'inturned cheeks projecting from the sides 'thereofzto engage said undercut rebates.

6. Anartific'ial tooth comprising a. porce-' lain or like facing having a recess in its inner upper portion forming an acute angle at its bottom and with undercut rebates tudinal median hole of said facing which around the sides of said recess, and a metal hole opens into said recess. back fitted in said recess with its bottom in- In testimony whereof, we have signed our 10 terlocking with the bottom thereof and with names to this specification.

5 inturned cheeks projecting from the sides thereof to engage said undercut rebates, said ABRAHAM SCHWARTZ. back bearing also a pin engaging in a longi- JOHN VVIEDER.

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