US2932893A - Artificial tooth - Google Patents

Description

April 19, 1960 M, MARDER 2,932,893

ARTIFICIAL TOOTH Filed June 7, 1955 FIG.2

INVENTOR.

M ax M avd mr Q3 WQ QSQULM limited States Patent O "ice ARTIFICIAL TOOTH Max Marder, Paris, France Application June 7, 1955, Serial No. 513,695 Claims priority, application France November 10, 1951 Claims. (Cl. 32-10) The present invention relates to artificial teeth to be used by human beings.

More particularly, the present invention relates to faeings of artificial teeth.

The present application is a continuation-in-part of application Serial No. 301,744 filed July 30, 1952, and now abandoned and entitled Artificial Tooth, of application Serial No. 301,745, filed July 30, 1952, andnow abandoned, and entitled Artificial Teeth, and of application Serial No. 272,920, filed February 23, 1952, and now abandoned and entitled Artificial Tooth.

In the art of artificial teeth, the most desirable results are produced when an artificial tooth, or at least the visible facing thereof, resembles a natural tooth so closely as to be indistinguishable therefrom. Thus far, this result has not been produced because conventional facings of artificial teeth are made of translucent materials which to the naked eye appear darker than natural teeth because the facings appear to have the color of the cement located behind the facing.

One of the objects of the present invention is to provide an artificial tooth facing which, when in use, resembles a natural tooth so closely as to be indistinguishable therefrom.

Another object of the present invention is to provide an artificial tooth facing with a light reflecting and diffracting means capable of giving the facing a natural appearance. .A further object of the present invention is to provide a light reflecting and diffracting means of the above type which at the same time serves to improve the strength of the artificial tooth and the security with which it is mounted.

With the above objects in view the present invention mainly consists of an artificial tooth which includes a translucent facing having a front surface adapted to be exposed when in use and a rear surface adapted to be joined to a support for the facing. A foraminous diffracting and reflecting sheet means, preferably made up of silver coated filaments of circular cross section, engages the facing and is located adjacent the rear surface of the facing for reflecting and diifracting light passing through the front surface thereof into the facing back through th'e'jfacing and out through the front surface thereof and for giving to the facing a coloring closely approximating that of aInatural tooth. v

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects andradvantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

Fig. 1 is a sectional view taken in a horizontal plane through a vertically positioned facing constructed in accordance with the present invention;

2,932,893 Patented Apr. 19, 1960 Fig. 2 is a perspective view of another embodiment of a facing of the present invention as seen when looking toward the rear surface thereof;

Fig. 3 is a side elevational view of another embodi ment of a facing constructed in accordance with the present invention;

Fig. 4 is a sectional view taken along line 4-4 of Fig. 3 in the direction of the arrows;

Fig. 5 is a partly sectional view taken along line 5-5 of Fig. 3 in the direction of the arrows; and

Fig. 6 is a sectional view on an enlarged scale corresponding to Fig. 4 and illustrating the principle on which the invention is based.

The present invention is limited to facings for artificial teeth, and these facings can be supported in a conventional manner. The facings are made of a translucent material so that light can pass therethrough. Thus the facing may be made of a translucent ceramic material such as porcelain or of a translucent synthetic resin such as an acrylic resin. A natural tooth does not have a uniform color, and therefore the material of the facing of the present invention is not relied upon to give the facing the coloring which it appears to have when used. Instead, a foraminous sheet means, such as a gauze sheet, is in engagement with the facing of the invention, is located adjacent the rear face thereof, and has an extremely white color so that the coloring of the facing of the invention is provided by light reflected with diffraction from this foraminous sheet means back through the facing toward the observer. In this way, as will be apparent from the description which follows, the facing of the invention has a uniform color which very closely approximates the coloring of a natural tooth. The reflected rays cross each other and mask the darker elements behind the facing. It is possible to manufacture the facings of the invention by molding them in suitably shaped molds.

Referring to Fig. l, the facing 10 shown is made of any of the above mentioned translucent materials and has a foraminous sheet means 11 embedded therein. It will be noted that the sheet means 11 is located adjacent therear face 12 of the facing 10 and has an omega cross section. In the remainder of this specification it is to be understood that an omega cross section signifies a shape corresponding to that of the Greek capital letter omega. This sheet means 11 is preferably in the form of a metallic gauze consisting of a mesh of extremely fine filaments. As was pointed out above the best results are obtained by a foraminous sheet means which is as whit-e as possible. Thus, the metal of the gauze sheet cannot be platinum, for example, because such a metal is gray rather than white. It is preferred to make thegauze sheet 11 of wire filaments which are coated with silver. This latter construction has been found in practice to give the best possible results. The facing 10 shown in Fig. 1 may be supported on a bridgework or the like in any conventional manner.

Fig. 2 shows a facing 13 made of any of the above materials and formed in its rear face with anelongated groove 14 which gives the rear face an omega-shaped cross section. Thisgroove 14 is adapted to receive a post of a support in a known way for mounting the facing. Against therear surface 15 of the facing 13 is located the foraminous sheet means 16 which is preferably in the form of a metallic gauze sheet made up of a fine mesh work of silver coated filaments. It will be noted that the sheet means 16 covers the surface of thegroove 14 in addition to a substantial portion ofrear face 15 beyondgroove 14. The sheet means 16 may be joined to the facing 13 as by being partially embedded therein during the molding thereof, or any adhesive may be used for this purpose. As was pointed out above and as will be further discussed below the foraminous sheet means of the invention gives the facing a very natural coloring. in the embodiment of Fig. l, the sheet means 11 performs the additional function of reinforcing the facing, and in the embodiment of Fig. 2 the sheet means also reinforces the facing and additionally provides it with a rough rear surface which increases the security of the mounting of the facing. That is, when an adhesive co operates with the irregular rear surface of the facing of Fig. 2 to fasten this facing to a support, the bond is much stronger than would be the case ifrear surface 15 were smooth. The rough rear surface is provided by pressing the sheet means against the rear surface of the facing while the latter is still plastic, and the material of the facing fiows throughthe spaces between the filaments to provide the facing with rearwardly extending projections as shown in Fig. 6.

In the embodiment shown in Figs. 3-5, the facing 17 has a rear surface made up of arear surface portion 18 and a rear surface portion 19-, these latter rear surface portions being substantially at right angles to each other.Facing 17 is made of a-ny 'o'f the above mentioned translucent materials. Only therear surface portion 19 is formed with anelongated groove 20 to giverear surface portion 19 an omega-shaped cross section. Fig. 3 shows in dot-dash lines aconventional support 21 carrying the facing 17 and having a post of omega cross section mating with and fitting into thegroove 20. A foraminous sheet means is embedded within the facing 17 closely adjacent to therear face 13, 19 thereof, as shown in Figs. 3-5. This foraminous sheet means is preferably a metallic gauze as described above and includes aplane portion 22 located adjacent therear surface portion 18 and aportion 23 of omega cross section located adjacentrear surface 19 and conforming closely to thegroove 20, as shown in Fig. 4.

As is evident from the enlarged sectional view shown in Fig. 6, the gauze sheet which forms the forarninous sheet means of the invention'is composed of filaments 24 which are coated with silver and which are of circular cross section. This gauze sheet is pressed into the rear surface of the casing facing while the material thereof is still plastic to provide the facing with realwardly extending projections surrounded by the filaments of the gauze sheet.

The principle of the invention can be understood from Fig. 6 with respect to the parallel light rays A and B of monochromatic light which move in the direction of the arrows toward the facing of the invention. As is evident from Fig.6 parts of these light rays are reflected from the front surface of the facing as light rays A and B The remainder of these light rays enter into the facing and are refracted to form the light rays A and B respectively. The light ray B strikes one of the filaments and then moves back through the facing toward the front surface thereof as the light ray B this latter light ray being refracted again at the front surface of the facing and emerging as light ray B On the other hand, the light ray A encounters another filament 24 and then moves back toward the front surface of the facing as light ray A this latter light tr'ay being refracted at the front surface of thefacing and emerging as light ray A It will be noted that thelight rays A 'and A -cross'overthe light rays B and B When it is considered that an infinite number of light rays move in the manner indicated for the light "rays A and B and that these lightrays cro's's each other in the material ofth'e facing an infinite number of tiiries, it *v'vill'b'e understood that these light rays "serve to mask any dark colors of the elements which carry the facing "so that these 'dark colors cannot give the facing 'a'n'unn'atirrhl appearance.

It should also be noted that the cross sectional area of the projections of the facing which extend re'arwardly through the gauze sheet is substantially smaller than the cross sectional area of'the filaments which makeup this sheet. This is a further feature which contributes to the desired results.

It has been found in actual practice that the above described structure provides an artificial tooth facing which cannot be distinguished from a natural tooth, when in use. This result is obtained by the translucency of the facing and by the extreme whiteness of the silver coated filaments of the forarninous sheet means.

It will be understood that each ofthe elements described above, or two or more together, may also find a useful application in other types of artificial teeth differing from the types described above.

While the invention has been illustrated and described as embodied in facings for artificial teeth, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully re've'al the'gist of the present invention that others can by applying current knowledge readily adapt it'for various 7 applications without omitting features that, from the.

standpoint of prior art, fairly constitute essential characteristics of thegeneric or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. For use in an artificial tooth, in combination, a {racing itavrng a front surface adapted robe exposed when in use and a rear surface adapted to be joined to a sup port for "the facing, said facing being made of a translu'ce'ht 'rn'olded material through which light can pass; 'and a game sheet of a light color engaging said'facing and located adjacent the rear surface thereof for diffracting and reflecting light passing through said front surface of "said fa'cin'g into the latter back through said facing and out through said front surface thereof and for giving to the facing a coloring closely 'aproxirna'tingthat of a natural tooth. j

"2. For use in an artificial tooth, in combination, a facinghaving a front surface adapted to'be exposed when in use and a rear surface adapted to be joined to a support 'f'orfthe facing, said facing being made of a translu'ce'nt molded material through which light can pass; and a gauze sheet of a light color engaging said facing andllo'c'ated adajacent'the rear surface thereof for diffracting and reflecting light passing through said front surface of sate facing into the latter back through said facing and out through said fro'ntsurface thereof and forgiving to the facing a coloring closely approximating that of a natural tooth, sa'id rear surface of said facing having a plurality of projections which extend rearwardly through said gauze sheet. 7 3. --For use in an artificial tooth, 'in combination, a facing having a "front surface adapted to be exposed when in use and a rear surface adapted to be joined to 'a support "fo'r't-he facing, said facing being made of a translucerit "molded material through which light can pass; and a gauze sheet or alight color "composed of individual "iet'all-ic filaments "of circularj'cross section, engaging "s' dieting and loc'a tedadjacentthe refar'surfac'e thereof fi st diffracting anti Iiefl'e'c'tin'g light passing through said front surface of said facing into th eflatter back through said :facing g'a'n'd out through said front surface thereof anujrorgivingtb -the facing a coloring closely approxie I'Iiiaftinfg that 'bfh'.rti1'tilfal"f0'dth. I 1

4. For use :in an "artificial tooth, incombina'tion, a

facing-having affront s u'rface'fadapted'to be exposed when in e and fa frat surface adapted "to be joined to 'a su port forthe facing, said facing being made of a translucent molded material through 'which light can pass; and a gauze sheet of a pure white coro'r composed of individual 'silver coated 'filairfeiits of circular cross section,

engaging said facing and located adjacent the rear surinto the rear surface of the facing, while the material face thereof for difi racting and reflecting light passing thereof is still plastic, until the rear surface is provided through said front surface of said facing into the latter with projections extending through the gauze sheet. back through said facing and out through sa1d front sur- References Cited in the file of this Patent face thereof and for giving to the facing a colormg closely 5' approximating that of a natural tooth.UNITED STATES PATENTS 5. A. process for manufacturing a facing for an arti- 1,296,009 Richards Mar. 4, 1919 ficial tooth, comprising the steps of molding a facing 2,147,403 Freedman Feb. 14, 1939 from a translucent material; and pressing a gauze sheet 2,572,377 OMorrow Oct. 23, 1951

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