US2265391A - Artificial tooth - Google Patents

Description

Dec. 9, 1941. s. MYERSON ARTIFICIAL TOOTH Filed April 27, 1938 "DEN. y

jzvev-zziar Z a 53371 2177 Patented Dec. 9, 1941 UNITED STATES-PATENT OFFICE ARTIFICIAL TOOTH Simon Myerson, Brookline, Mass Application April 27, 1938, Serial No. 204,512

1 Claim. '(Cl. 3210) This invention relates to improvements in artificial teeth and backings therefor.

The purpose of the invention is to provide an artificial tooth having a gingival contact of porcelain, and also an occlusal or biting portion of porcelain. By the construction of my tooth and backing I have provided an extremely strong and easily workable porcelain member and backing member having, in addition, the advantages of i wide range of application in the restoration of lost teeth as well as preserving a highly aesthetic appearance. For convenience of description I shall designat the porcelain or the like member as a tooth; and

the metallic or like member as the backing; and

that portion of the tooth to which the backing is to be fitted as the body portion; and the remainder of the tooth as the crown portion. It

follows as a matter of course then that the gindesignated throughout the several views by the" same reference characters.

Fig. 1 is a side view of a posterior tooth made in accordance with my invention;

Fig. 2 is a buccal view of such a tooth;

Fig. 3 is a lingual view of such a tooth;

Fig. 4 is a perspective view of one type of backing to be used with a tooth shown in the preceding figures;

Fig. 5 is a perspective view of an optional backing;

Fig. 6 is a side view of the assembled tooth and backing, after the backing has been completed as herein described;

Fig. 7 is a buccal view of a bridge in the mandible extending from the first molar to the cuspid, this bridge carrying two bicuspid dummies made in accordance with this invention;

Fig. 8 is a top view of the bridge shown in Fig. 7;

Figs. 9, 10 and 11 are sections respectively on lines 99, IIJI0 and Il-H of Fig. 2;

Figs. 12 and 13 are sections on lines |2l2 and |3-| 3 respectively of Fig. 6;

Fig. 14 is a side View of an anterior tooth; and

Fig. 15 is a perspective view of a backing therefor.

As shown particularly in Figs. 1, 2 and 3, an artificial tooth formed in accordance with this invention may be provided with a smooth body or base I, which tapers slightly from its upper or 5 of occlusal end downwardly toward its gingival portion 5 on all of its faces. This tooth is provided with a crown 9 having a buccal face 2 and a lingual face 3; the upper part of the crown obviously provides the occlusal face 4 of the tooth. At each side of the tooth, the recessed base portion or body portion may be provided with an extension 6 which may extend to the occlusal face, thus separating the buccal portion 2 and the lingual portion 3 of the crown, these portions of the crown being offset relative to the base and its extensions 6. The crown portion 2 is thus provided with a shoulder or margin 1, while the crown portion 3 is provided with a similar shoulder 1*. These shoulders, as shown in Figs. 1, 2 and 3, may extend downwardly from the occlusal face 4 of the tooth. Thus the shoulder I may extend downwardly along the mesial portion of the tooth toward the gingival portion across the buccal face and to the occlusal surface on the distal aspect of the tooth. The margin or shoulder I may extend from the occlusal face of the tooth on its mesial aspect toward the gingival portion of the tooth and across the lingual face to the occlusal surface on the distal aspect of the tooth. If desired, the shoulders may be slightly undercut. It is evident that the crown portions 2 and 3 provide surfaces which are continuous with the occlusal surface 4 of the tooth.

A tooth of this type may receive a backing H] with a ring-like or annular lower portion substantially or preferably entirely to encircle the body I of the tooth. This backing has a buccal aspect II and a substantially higher lingual aspect l2. The backing is also provided with-lateral extensions I3 to fit within the recessed portions 6 of the tooth. The backing may be provided with front and rear flanges l4 and M adapted to engage the shoulders 1 and 7 respec-- tively; the flanges are preferably free of sharp corners at the regions where the extensionsv i3 join the annular body portion. The backing is provided with a lower edge or gingival margin I6 substantially to conform to the shape of the gingival portion of the tooth.

Fig. 5 illustrates an optional form of backing Hi with buccal and lingual aspects ll and I2 respectively and with extensions l3 In general this backing is similar to that shown in Fig. 4, but the flanges l4 and Id are omitted, and relatively thick upper edges l3 and l3 are provided to engage the shoulders I and 7 respectively of a tooth.

Fig. 6 shows the manner in which a backing the type shown in Fig. 4 may be assembled with a tooth of the type shown in Figs. 1, 2 and 3. In this figure the buccal and lingual portions of the backing are shown in dotted lines and are designated respectively by numerals II and I2. As shown, a body of solder It may be disposed beneath and between the flanges I4 and I4; rather than solder, casting gold or other material may be employed to complete the backing. The lower, exposed portion of the body is designated by the numeral E9 in this figure.

Figs. '7 and 8 show natural teeth 29 and 2!, namely, a first molar and a cuspid used as abutments to carry the artificial teeth 22 and 23. Inlays 24 and 25 are shown in dotted lines in Fig. '1, being soldered or otherwise joined to the backings. The exposed gingival portions of the bases of the teeth are designated by the numerals 1-9 in Fig. 7 and the exposed buccal portionsofthe crowns of these teeth by the numeral 9. As shown in Fig. 8, solder w or the like-maybe employed to join the extensions l3 of .the .backings.

In Fig. 14, corresponding reference numerals designate parts similar to those shown in Fig. 1, except that the incisal portion of the anterior teeth .is designated by reference character 4.

Fig. 15 shows a backing Ni which may be employed with such a tooth .and which is provided with a 'buccal aspect H and a lingual aspect 152 as wellasextension 13 In practice, I use a molar or bicuspid tooth,

- asshown for example in Fig. 1, and a thin backing such as is represented in Fig. 4,'w;hich has ibeen made to closely fit the porcelain tooth body. In the manufacture of my tooth in porcelain, it is;r,eadily-feasible to control the size of the tooth to fairly constant dimensions with occasional maximum variations of from .005 to .010 of an .inch. Moreover, the backing may-be slitat any :point so that it may be taken up to fit the tooth iif loose, or if 'itbe tight it can be readily stretched by light tapping with a hammer, or be burnished,

as preferred. I prefer to use the closed backing :as illustrated in the figures,asthe slight'stretchting, where necessary, is so easily accomplished. In selectingteeth for the case, I select teeth "that go freely into their places and which require a .Lminimum of gingival and occlusal grinding. Having fitted the teeth into their position, I 'then'burnish the backing andthe flanges (if the -flange type of backing is used) and theextend- .iing .portions to fit the body and shoulders and the crown margins.- Then "I swa'ge the backing 'to the tooth andthen'complete the backing "by :waxing to the proper :contours, thereafter re- :moving the tooth :from its backing, :the investing and castingbeing done in the usual manner. Itwill'be-seen' that the backing forms-a strong and rigid encasement for the tooth body and that the extensions provide convenient "and properly located ineans-for joining the -backing -members of the teeth :to any typeo'f abutment 'orto other backing members andthat the extensions-of the backing form valuable reinforcement to the rest o-fthe backing in resistance to strong lingual-buccal forces of mastication; and "that they also provide the .utmostmechani- .cal advantage against these iforcesbecause the juncture w can take place close to, -if not exactly .atthe same level .at which ,theforces areapplied.

Also, this construction provides a hygienic advantage in "that the -juncture;may.be made as .yfar easmeeessary; from the gum tissue and, makes -a more rigid one, as follows: Adapt the pliable backing in the manner already described, set upon this backing a rigid backing, leaving margins of the pliable backing exposed, remove, and

solder the two together.

In making a bridge or denture with my dummies, any type of abutments may be used, including removable types. In the bridge which I have chosen for illustration, inlay abutments have been used. The inlay abutments are fitted 'to place and a wax bite is taken with the jaws in properfull centric occlusion. After this an impression is taken; the abutments should come oif with the impression or be placed in he impression should this be necessary. Articulated models should be poured in the usual manner. The individual dummies ,should .each be separately fitted and completed, then fixed in place with wax. The teeth should be oiled before being fixed in place upon the model, so that the wax will stick to the backings and not to the teeth. The teeth should then be removed from the backings and. the bridge invested and completed by soldering the members together as is .customary in the art. Ifthe gingival surfaces of the teeth have been ground, they should be re- 1 glazed before they are'cemented to their backings.

The completed bridge will be seen to have many advantages over the prior art. The porcelain members only of the dummies contact the gingiva. Each individual dummy-can be finished to smooth-and natural contours and be free from food-retaining poekets. The gold or othermetal membersare freely-accessible to cleaning Witha tooth brush or other means, and can quite readily be kept clean. The construction secures the maximum strengthfor-the amount of metal used and also h maximumt ethin he-porcelai tooth, the porcelain tooth also having an exposed occiusal of porcelain. ;It be seen that lower ;molars and .bicuspids :as Well .;asanteriors,

made after my invention, will :show very little metal, that part of the backing which crOsses the buccal orlabial aspects of the tooth being {entirely invisible in lower bridges. In upperteeth this is not true in ;all cases, especially with .relation totheanterior teeth, as some people expose their anterior teeth much more :thanothers ,do. The advantages gained, however, more than offset .this possibility. In cases .where it iis'indi- .cated, one .may use a metal of vless conspicuous color than thegold alloysordinarilyused.

Although I have not .shown a molar dummy in the illustrations, it is obvious that theconstruction mightrbe similar to that illustrated, in

all the figures except Fig. '14.

It should-be understood thatthe present-disclosure is for the purpose ofdllustration only and that-this invention includes all'modifications-and equivalents which fall within the scope of the appended. claim.

,an annular .lower ,portion for substantially ,en-

tirely encircling the base of a tooth, said backing having a lower edge to conform to the gingival portion of a tooth, said backing having extensions to project substantially to the occlusal surface of the tooth at the mesial and distal sides thereof, the backing being provided with a flange extending along the front edge of one of said extensions and along the upper edge of the buccal portion of the backing and thence along the front edge of the opposite extension, the backing having a second flange extending along the rear edge of one extension, along the upper edge of the lingual portion of the backing, and then along the rear edge of the other extension, the buccal portion of the backing having a smaller depth than its lingual portion.

SIMON MYERSON.

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