US1426661A - Artificial tooth - Google Patents

Description

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VINCENT MALLON, OF NEX YORK, N. Y., ASSIGNOR TO DENTAL MANIKTN HEAD CO.

TNC., A CORPORATION 0F NEVI YORK.

ARTIFICIAL Toorn.

meneer.

Application filed October 26,1920.

To ,all wzo/mj it may concern.'

Be it known that I, VINCENT MALLON, a citizen of the United States, residing in New York, in the county and State of New York, have invented new and useful Improvements in Artificial Teeth, of which the following is an exact and clear specification.

The invention relates to an artificial tooth of the type which includes a formed metallic denture or backing which is usually a casting and a facing which is usually of porcelain or similar composition, secured to the backing by an adhesive, such as cement, and in which the connection between the facing and backing includes a dovetail interlocking joint.

One of the objects of the present invention i is to provide an improved character of joint between the facing and its backing so as to.

insure the positive retention of these parts in their preset position even after prolonged use.

The efficiency of such jointures depends largely upon the effectiveness of the adhesion between the contacting surfaces and accordingly the invention features an improved form of adhering surface between the facing and its backing. This is attained largely by increasing the area of they adhering surfaces over the area provided by a corresponding lat surface and one convenient means for attaining this increase of surface is to make the contacting surfaces of a curved configuration.

Still another object of the invention is to provide a tooth facing which will have sufcient body to maintain its configuration and give the necessary incidental strength and at the same time which will not expose any more of its body than is necessary to provide the facing, leaving the metal backing to provide the necessary bulk and strength to the completed tooth.

ln order to attain this object the facing is formed with a thick central or medial portion where requisite strength is desired, progressively decreasing in crosssectional thickness and thus thinning out to all edges which are reinforced by any desired or permissible thickness of metal or other strain resisting backing. I

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying draw- Specification of Letters Patent.

Serial No. 419,591..

ings and in part will be more fully set forth in the following particular description of one form of mechanism embodying my invention, and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

ln the accompanying drawings Figure 1 is a view in front elevation of a backing constituting one of the two elements of the completed tooth constituting a preferred embodiment of the invention;

Figure 2 is an elevational view of the rear side of the facing constituting the other element of the disclosure;

Figure 3 vis a side view of the assembled elements forming the complete tooth;l

Figure 4 is a transverse sectional view taken centrally through the tooth shown in Figure 3, taken approximately on the line 4 4 of Figures 1 and 2; and

Figure 5 is a horizontal sectional view taken on the line 5 5 of Figure 3.

In the following description and in the claims, parts will be identified by specific names for convenience of expression but they are intended to4 be as generic in their application to similar parts as the art will permit. j

In the drawings and referring particularly to the showing in Figure 1 there is disclosed a backing 10 in the form of a casting of metal, such as gold or other material usually employed in such work. rlhe front side 11 of the backing is provided with a dove-tail shaped flat` socket 12 which opens through the ridge lap end 13 and is defined on opposite vertical sides by re-entrance grooves 15 which converge down wardly and inwardly to a horizontally dis-` posed stop or ledge 16 defining the lower end of the socket. The front surface 11 of the backing as well as the back surface 17 of the socket is curved in two directions, both vertically and horizontally when considering the tooth in normal position. lt is equally within the scope of this disclosure to consider the surfaces 11 and 17 as the outline of some conic section but it is simpler to consider the surfaces as having no definite geometric shape but simply as parallel concaved surfaces.

Referring to Figure 2 for a detailed description of the facing, it is to be understood that it is designed to conform exactly to the configuration of the front sides of the backing. ln order to obtain the desired exactness of fit, the facing is used asa core in forming the mold for the backing. The facing includes a body portion which is of double convex form with a relatively thick central portion, particularly designed to strengthen the same along the vertical medial plane reducing in thickness and thus thinning out t0 all edges. r

The `upper rear portion of -tlieffacingis provided with an integral extension 18 which is clove-tailed shape in elevation and is fitted within the socket 17. `'.lhe lower side of the projection constitutes a ledge 19 for engaging the seat 16 andcoacts therewith to prevent downward movement of the facing towards the biting edge Z0 of the tooth.

`The convexity of the front face 21 of the facing corresponds in so far as is possible to the usual curvature of the front face of a natural tooth and of course will vary in outline with thedifferent character of teeth which it is designed to simulate. The convexity of the rear side of' the facing, considering both thevbody of the facing as well the projection will be such as to conform to the correspondingly curved front surfaces of the backing. Following usual practice the contacting lsurfaces are cemented together by a thin layer ofk cement 22. 'The facing isinserted in the 'backing by moving the projecting dove-tail into'the uppeiopen end of the socket, i. e. vfrom the gum end of the tooth and moving the facing into its prelocated position in the socket withthe pro- `iection engaging the seat and of course with the cement layer therebetween. TWhen so positioned the-only part of the facing ex- Y posed will be the front face, for both the distal `and mesial side of the tooth will be defined by the relative thick metal backing whichextends to the outlining edge olf-"the backing, as shown in Figure 3.

this construction there is provided the largest. possible adhering surface that can be formed, takingr into consideration the necessary space limitations within which the entire tooth must be accommodated, taking into consideration the necessity for apportioning the facing and backing so as togive enough strength to the facing to maintainr its configuration and taking into consideration the necessity to defeat yany'tendency of the facing tocrack. By this construction it is possible to lutilize the remaining available space to accommodate'a massofmetal backing sufficient to vgive the` maximum amount of tensile strength required of the complete tooth.

l claim 1. An artificial tooth including a formed metallic backing provided lwith an open top, dove-tail socket in the front face thereof and an upwardly facing seat defining the lower portion of the socket, and a facing` provided with a dove-tail projection on the rear side fitted in said socket and engaged by said seat to prevent relative movement of the facing toward-s the bite end of the tooth, said facing adhering to the backing over a contact surface disposed in more than one plane thereby to increase the area of the adhering surface beyond the area of a flat cont-acting surface within the projected outlines of. the tooth. n.

2. An artificial tooth including a formed metallic backing provided with anopen top, dove-tail socket on the front face vthereof and an upwardly facing seat defining the lower portion ofthe-socket, .andy a facing provided with a dove-tailprojection on the rear side 4fitted in said socketja-nd engaged by said seat to prevent relativeniovenient of the Vfacing towards thebite end of the' tooth, said facing adhering to the backing over a contact surface curved in one direction thereby to provide a relatively extensive contacting area. f 1

3.4 An artificialtooth including a backing and a facing adhering tothe backing,

the' contacting surfaces between the backing and facing being curved fromedge to edge. 4. An artificial tooth including` a backfacingbeing curved from edge to edge in two directionsat right anglestoeach other.

An artificial tootliincluding' a. facing,

double convex in horizontal section, provid' '95 ing and a facingadheringftothe backing, the contacting surfaces between the backing and fitting one ,side of the Ifac-ing and having'a relativelythick distal and mesial side to provide strength to the tooth as a whole, saidsideshaving their forward edges terminating approximately at the meeting edges of said'double convex sides leaving the front side of the facing exposedv and acting to coriceal thermetallic backing. A

6. An article of manufacture constituting a facing for an artificial tooth, said facing being of one-piece`v and having a general double convex form and a yprojection extending from` one facethereof-andconstituting part of a meansv for mounting the facing in place. l

.p VNGENT' MALLON. litnessesz y f y i B. NiooLAr, H. CRONEMEYER.

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