US2602226A - Artificial teeth and backing therefor - Google Patents

Description

July 8, 1952 K PECK 2,602,226

ARTIFICIAL TEETH AND BACKING THEREFOR Filed Jan. 29, 1948 6/2arle5 K .Pe ck Patented July 8, 1952 THEREFOR Charles K; Peek, New York, N. Y.

Application January 29, 1948, Serial No. 5,127

Claims.

This invention relates to. improvements. in artificial teeth. and backing therefor. It, more particularly; has to dowith a type of novel construction that can be utilized in the initial fabrication of a unitary bridge andwherein other, teeth may be replaced .or interchanged in lieu of the original or previous ones used. The teeth-andv b'ackings of: this invention have certain advantageswhen employedin fixed bridgework and are likewise .advantageouswhen used in association with the various kinds: of removable bridgework.

Heretofore the metal framework of dental bridges. has commonly'been'composed of .various kinds: of golds or stainless. steels but. there has been" a long. feltt need for. acombinationand design. .ofstructures that. would give adequate strength :while keeping clown; the display ofzmetal. viewable fromzthe labial side of the. bridge. This. unsightly display has been especially, observed in the contact areas, in between the teeth, at the incisaliedges orzon the occlusalsurfaces when the patients mouth was open'as. in laughing or talking; Further; there has long -been-a-need for a tooth structure: of sufiicient bulk and thickness tonullify any influence of the backing reflecting through the tooth structure or otherwise adverselyeffecting the shade or color of thetooth; such. shortcomings have' not permitted the-tooth to have its intended values in shade control andtranslucency. Moreoven'there h'as been a need fora replaceable tooth that would bemore sani-- tary or hygienic-while in service in the mouth; also, a tooth-thatwould give efiicient service and wouldnot'become objectionably discolored'due to the washing out of dental cements and the ingress of= stains such-as may be caused bytobacco or certain medicines and the like. Thespace created-by the disintegration of cement also cre-- ates aharbor for decomposing foodparticles and for'bacteria which can'adversely affectthe state ofhealth of the patient besides creating an offen sive bad breath toward others. The bacteria-can be: pathogenic or non-pathogenic but if pathogenic they may invade the human body by way of the blood stream or through the digestive tract.-

Replaceable teeth of theprior art-have fre quently broken either because of their inherent weakness, because of the'disintegration of the dental cement, or because the teeth-were not designed for universal use in all sections of the mouth and for-all kindsof bites for whichthe dental. practitioner produces bridges. such breakage's' of teeth-are not onlyembarrassing to the::-patient, but their loss from the bridge im 2 7 pairs the efiiciency' of mastication for the period of time they are out and also present a certain amount of inconvenience, loss'of time and'added expense to the patient in having the repairs made.

A certainamount of artificiality has been common heretofore in bridges where teeth of commercial dental manufacturers'have' been ,used.

The unharmonious appearancesometimes couldbe traced to improper tooth: form orsometimes to improper shades or to-the improper amount of translucency and the like when suchteeth of commercial manufacture were compared with the remaining natural teeth of a patient. This has brought a long felt need for a tooth struc-- ture that-couldbe fabricated ina tailor-made fashion as itwere by the dentist or they dentists mechanical technician for each individual patient.

Under such conditions of fabrication, the dentistcan conduct. certain fact-finding observations of the patients natural teeth and can virtually write .a prescription whereby the teeth of the bridge, structure will harmonize and precisely simulate the natural teeth inform, characterization, shade, translucency and the-like. While I am. aware that certain. materials have been 'used and certain technics have been advanced in dentistry heretofore whereby a certain elementary approach to tailor-made teeth has been accomplished, yet these materials and technics have fallen far short of the professional needs, In my improved artificial tooth structure and the backing mount, which constitute the present invention, I have overcome all of the above shortcomings of the prior art and I have provided certain effectual advantages that will be hereinafter explained in detail.

One of the objects of myinvention is to provide a'dental bridge consisting of an assembled metal framework, a portion of which is one or more of myrmet'al backingv mounts, and one or more artificial teeth composed of a suitable plas backing mounts in assorted widths and lengthsv whereby the encompassing backing member may be adjustably bent to accommodate minor variations in tooth width:

Another. object of my invention is to provide preformed plastic teeth of a kind, shape andv shade than'can be usedto replace any tooth member previously employed on the bridge whether the bridge is or is not anchored in the mouth of the patient.

Another object of my invention is to provide plastic teeth of the type described in various sizes and shades as articles of manufacture.

In the drawings:

Fig. 1 shows an elevational end view of the pair of dies and punch I use in the process of bending my curved backing;

Fig. 2 is a plan view of the first step in making my curved backing;

Fig. 3 is an elevational side view of the tenon (post, rib and lugs) that forms a part of my completed curved backing;

Fig. 4 is a front elevational view of the parts shown in Figs. 2 and 3 when in assembled order;

Fig. 5 is an edge elevational view of the backing of Fig. 4;

Fig. 6 is a similar view of my completed curved backing after the backin shown in Fig. 5 has passed through the dies and punch assembly shown in Fig. 1;

Fig. 7 is a side elevational view of a posterior (bicuspid) tooth made in accordance with this invention;

Fig. 8 is an elevational lingual view of the tooth illustrated in Fig. 7

Fig. 9 is a horizontal cross-sectional view of the tooth when viewed downwardly along the plane of the line 9-9 of Fig. 8;

Fig. 10 is a perspective view of a dental bridge wherein two of my backings, according to Fig. 6, are shown.

My improved backing is made preferably from a precious metal alloy, although it may be composed of any other suitable material. The backing is formed from sheets of the selected metal, which advantageously possess a thickness of the order of .012 to .018 of an inch. Such a sheet is passed through suitable blanking and punching dies, not shown, to produce therefrom a plurality of fiat, rectangular or square blanks of metal of the character shown at l in Fig. 2, which blanks possess required dimensions. Then, either by the blanking operation or by a separate operation, I punch one or more aligned holes 2 through the blank along its axial center line.

The tenon 3, shown in Fig. 3, is usually made of the same alloy as that used in the blank of Fig. 2 and is preferably T-shaped in transverse cross section. It may be of solid construction or of sheet-folded-hollow construction. If of solid construction, it may be made by rolling, drawing or swagging, or by a combination of two or more of these operations. In making the hollow T-shaped tenon, I prefer to use a gauge of metal comparable to that used in the blank. This sheet construction produces an oblong hollow-shaped post 4 which in combination with the web or rib 5 provides a T-shaped tenon 3. The tenon is then placed in a die and stamped to form the proper number, shape and size of lugs 6, see Fig. 3, to correspond to the number, shape and size of the .holes 2 that have been punched in the blank I. The lugs 6 are longer than the gauge thickness of the blank lso that when the tenon 3 and blank are assembledthe lugs protrude a sufficient amount to form an adequately strong clinching rivet 'I' as shown in Fig. 5.

The next operation is to place the backingof Fig. 5 in the combination of die fixtures shown in Fig. 1, wherein, 8 and 8' are the dies which when assembled have a cavity or mortise 9 which is the counterpart of the tenon shown on the backing in Fig. 5. In the process of bending the backing member I, the punch in is raised to an elevated position so that the tenon 3 can be inserted into the mortise 9 and then the punch strikes the backing a sharp descending blow with sufficient force to transform the member I of Fig. 5 so that in the end it conforms to the curved shape as shown in Fig. 6. I

It will be understood that I provide different widths and lengths of backing for molars, for example, or for bicuspids or for any of the anterior teeth. In fact, I contemplate backings ,to be used for any tooth, upper or lower, that will be found in the human mouth. The number of lugs B of Fig. 3 is determined to some extent by the length of the backing and also to some extent. by the masticatory stress which is exerted on the teeth in certain sections of the mouth.

In the construction of a bridge made according to this invention, I first prepare themetal framework to fit the articulation. Such a metal framework is shown in Fig. 10, wherein, by way of example only, I show at numeral H a Carmichael cast attachment or a three-quarter cast attachment for anchorage to an upper right natural cuspid tooth. The anchorage at the other end of the bridge consists of a full cast crown [2 to be cemented later to an upper right natural first molar. Between these abutment anchorages, I have assembled and firmly attached (preferably by soldering) two of my curved backings l3 and [3, which backings will later receive an upper right first bicuspid and an upper right second bicuspid plastic tooth made and produced in the following manner. As previously stated, the metal work of the bridge has been made to fit the articulation, then the bicuspid teeth are molded and formed to the bicuspid backings employing therefor any good working wax.

The wax teeth are shaped by carving for contour and cusp formation to the end that the wax teeth have harmonizing form and shape with the patients remaining natural teeth, proper articulation with the cusps of the teeth in the opposite arch and, proper adaptation to the gingival ridge. This work of carving is best facilitated by usingaccurately made models of the patients mouth and ,Which models are mounted on a good articulator. After the wax teeth are formed and carved, the metal frame work of the bridge, with the'wax teeth in place, is removed from the model andinvested in the manner commonly understood by thoseskilled in the art. The wax composition, of the wax teeth, is eliminated from the mold by one of the commonly used processes whereby the space occupied by the wax becomes a void within the investment. The void or voids have the counter-conformation of the wax teeth so thatthey become a. mold into which one of the unpolymerized plastics is packed. For-example, I may use a methyl methacrylate (acrylic) composition in certain desired colors or; ,sh ades andy pack these in themold in a manner so that whenv completely polymerized (cured) the finished plastic tooth will closely simulate the shade of the patients natural teethr It will be understood that the mold cavities;

contain my curved backings in a manner whereby the inner surface of thecurved member is exposed and the acrylic material is packed directly against it. Likewise the acrylic is packed against and around the tenon and over the incisal edge) and the proximal edges of the curved member.

so-that the cured tooth will be adequately sup.- ported against the stresses and strains of masticationwhen i i-service in themouth. Further, the acrylic tooth-is rigidly anchored to the backing becauseit has been cured in a ,Positiondirectly onthebacking and accordingly cannot be removed without virtually destroying or at least extensively mutilating it.

Bridges-made according to my invention are tailor-made for the patient. They are strong, the plastic teeth are shaded and contoured for the individual patient, all of which goestomake a highly satisfactory restoration that is more thoroughly effective in function and with esthetic qualities. that, so far as I am aware, havenever been obtained heretofore. V g

For those dentists who mayfind it necessary, for. .one reason or another, to remove one of. the plastic teeth from a bridge after it has been in service in the mouth or for the dentistwho may not desire to make a bridge in the tailor-made fashion, I supply a full line of corresponding plastic teeth as articles of manufacture. The teeth, according to my invention, will be marketed in an assortment of lengths,l-widths and thicknesses, and in a variety of shades, colors or blends so that they can be used as the so-called interchangeable teeth in association with my special backings. It should be understood that such a line of teeth is contemplated to include both anterior and posterior teeth for the upper and lower dental arches of mankind. Such a posterior (bicuspid) tooth I4 is shown in the drawings in Figs. 7, 8 and 9. Fig. 7 is an exterior proximal view of the tooth wherein a shoulder I5 is shown near its occlusal or incisive end and where one of the proximal shoulders I6 of the backing-receiving recess can be seen. The

. mortise which is composed of the bore or hole I! and the restricted slot I8 is shown in dotted lines. In Fig. 8, a lingual view of the bicuspid tooth is shown, wherein the shoulder near the occlusal or incisive end is shown at (5, the two proximal shoulders of the backing recess are shown at l6 and IS, the post bore or hole I! is shown in dotted lines and the slot is shown at I8. In Fig. 9 a transverse section through the tooth, looking toward the gingival end thereof, illustrates the arcuate configuration of the backing recess.

Artificial teeth so formed may be readily applied to the tenon post of the backing and cemented thereto for permanent retention. In the preferred technique in which the acrylic teeth are joined with the bridge backings or framework in a molding operation, the teeth are permanently bonded to the backings and cannot be removed therefrom in an intact condition. The arcuate or concave form of the backingsprovides an acrylic tooth of unusual depth, which is advantageous for shade control and translucency. Furthermore, the construction from a labial point of View dispenses with an unsightly showing of the metal framework. Due to their arcuate formation, the individual backings may be flexed, if desired, to vary somewhat their standard widths, thus adapting the same readily to the dimensional characteristics of the teeth employed in connection therewith.

In view of the foregoing, it will be appreciated that bridges made in accordance with my invention overcome the shortcomings or defects of the prior art and provide marked improvements in dental bridge functioning, esthetics and oral hygiene.

lclaim: J

-1. A backing; for the mounting. of. artificial teeth. comprising a plate having incisal, gingival and proximal edges, said plate possessingagdeep substantially uniform arcuate curvaturebetween its incisal and gingival edges in horizontalplanes for relativel-y. extended. engagement. with the lingual and proximal surfaces of any associated tooth andbeing straight and-unbowed injplanes parallerwith'its proximal edges; a plurality of relatively spaced vertically aligned. openings formed in said plate in the central region thereof, a tenonpost extending centrally and vertically of said'backing, said post projecting outwardly and laterally from a tooth-mounting surface of said backing andformed along its outer longitudinal edge-with an enlarged head, the latterbeing joined". with a Web of reduced cross-sectional thickness. as compared with. that of said. head, and apluralityof spaced lugs integrallyprojecting from theinner vertical edge of the .postweb, said lugs being positioned in the. openings of said backing and being of such length as to. extend through and'beyond said openings to provide ends adapted for clinching engagement with lin ual surfaces. of the backing, said post terminating at one endsubstantially evenly withithe gingival edge of the backing and at its other end short of and in spaced relation to the incisal edge 7 of said backing.

2. A backing for the mounting of artificial teeth comprising a plate having incisal, gingival and proximal edges, said plate possessing a deep substantially uniform arcuate curvature between the incisal and gingival edges thereof in planes passing horizontally therethrough for extended engagement with the lingual and proximal surfaces of an associated tooth and being substantially straight and unbowed in vertical planes passing therethrough between its proximal edges,

- the center of said plate being formed with an opening, a tenon post extending centrally and vertically of said backing between its incisal and gingival edges, said post projecting outwardly and laterally from a tooth-receiving surface of said backing and being formed along its outer longitudinal edge with an enlarged head, the latter being integrally joined with a Web of reduced cross-sectional thickness as compared with that of said head, and lug means integrally projecting from the inner vertical edge of the post web, said lug means being positioned in the opening of said plate and being of such length as to extend through and beyond said opening to provide ends adapted for clinching engagement with lingual surfaces of the plate, said post terminating at one end substantially evenly with the gingiva1 edge of the backing and at its other end short of and in spaced relation to the incisal edge of said backing.

3. A backing for the mounting of artificial teeth as defined in claim 2 and wherein the tenon comprises a sheet of material folded upon itself to form a hollow post head.

4. In a dental bridge, a framework having a tooth-receiving backing of arcuate configuration and formed from plate material of suificient thinness to admit of flexing thereof to vary its effective width, a rigid tenon post extending longitudinally of the tooth-receiving surface of the backing from its gingival edge to a position adjacent to but short of its incisal edge, an artificial tooth joined with said backing, said tooth comprising a body composed of an acrylic plastic and having a recessed backing-engaging surface on its lingual side, said surface conforming to the configuration of said backing and including incisal and proximal shoulders adapted for engagement with the corresponding edges of said backing, said surface extending to the plane of the gingival surfaces of the tooth body and terminating short of and in spaced relation to the incisal surfaces of said body, and a slot provided in said tooth'body and opening to the recessed surface thereof to receive the tenon post of said backing, said slot conforming to the cross-sectional configuration of said post.

5..[n a dental bridge, a framework having a tooth-receiving backing of arcuate configuration and formed from plate material of sufiicient thinness to admit of flexing thereof to vary its effective width, a rigid tenon post extending longitudinally of the tooth-receiving surface of the backing from its gingival edge to a position adjacent to but short of its incisal edge, an artificialtooth joined with said backing, said tooth comprising a body having a recessed backingengaging surface on its lingual side, said surface conforming to the configuration of said backing and including incisal and proximal shoulders adapted for engagement with the corresponding edges of said backing, said surface extending to the plane of the gingival surfaces of the tooth body and terminating short of and in spaced relation to the incisal surfaces of said body, and a slot provided in said tooth body and opening to the recessed surface thereof to receive the tenon post of said backing, said slot conforming to the cross-sectional configuration of said post.

CHARLES K. PECK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 377,248 Genese Jan, '31, 1888 806,034 Whiteside Nov. 28, 1905 1,122,718 Fritz Dec. 29, 1914 1,465,473 Hansen Aug. 21, 1923 1,473,055 Steele 1 Nov. 6, 1923 1,584,438 Devlin May 11, 1926 2,230,164 Myerson Jan. 28, 1941 2,475,244 Kaufmann July 5, 1949 FOREIGN PATENTS Number Country Date 190,836 Switzerland July 16, 1937

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