US 2423330 A
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July 1, 1947.-
C. LEVINE METHOD OF MAKING DENTURES Filed April 18, 1945 TAKING IMPRE5$ION OF MOUTH TO FORM NEGATIVE FROM UCH NEGATIVE FORMING A FIRST PO$IT\VE DIE FORMING A ME H WAX PATTERN ON 5UCH FIRST-DIE cAsTme AME-rm. MESH mass on sucH FIRST DIE USING SUCH PAW-FERN CAST METAL ME5H DASE w FROM SUCH NEGATIVE FORMING A ssooflo POSITIVE DIE REMOVING SUCH 585E FRO/Y1 fiu'cH FlRsT'DlE AND TRAHSFERRING SUCH BASE 'T'o THE SECOND DIE FbRmme A DEIHTURE usme sucH a sz AI'IO sucH SECOND DIE Cffcatzas Levine REMOVING ucH DENTURE ITH 9/165 INCLUDED FR M fiUCH szcorm on;
awe/whom abtowwg Patented July 1, 1947 T :QUNITED 'sT r s PATENT I orr cs Charles Levine, Detroit, Mich.
Application April 18, 1945, Serial No. 588,968
This application relates to methods of manufacturing dentures.
The denture hereof is characterized by having as an integral part thereof, disposed against the tissue engaging surface of the denture, a cast metal mesh base. For an understanding of the denture of this application, reference will now be had to the appended drawing. In this drawing,
Fig. 1 is a flow diagram of the steps in the manufacture of the denture.
Fig. 2 is a transverse cross sectional view of the denture.
Fig. 3 shows the cast metal mesh base per se.
In the drawings, Fig. 1 is a flow diagram indicating the steps in the manufacture of the denture and their relationship to each other, while Fig. 2 shows the denture having a plastic plate i 0, teeth I I, and a cast metal mesh base [2 on the upper or tissue engaging surface of the plate. lhe mesh openings of the base are filled with the plate material but otherwise the shape of the denture with the base therein is exactly the same as the shape that the denture would have taken had it been made according to conventional practice, 1. e., without the cast metal mesh base in it.
The manufacture of a denture with a cast metal mesh base in place on the tissue engaging surface thereof will generally follow the conventional method of manufacturing of dentures with, however, slight variations. In the manufacture of dentures, it is conventional first to take an impression, a negative, and then to cast one or more positive dies from such impression. In my method, I cast at least two duplicate positive dies, using both of them. At this point, however, my method takes on a variation from the conventional method, for at this point, I make on one of the two duplicate dies a wax pattern of a cast metal mesh base to be cast onto that die, and then I cast a metal mesh base from such pattern onto that die. Both the forming of the wax pattern and the casting of the base from such pattern can be done according to techniques well known in dental laboratories. The casting may be by the well known lostwax method, wherein the die and pattern are invested in a suitable investing plaster which is heated to vaporize and destroy the wax to leave a space into which the casting metal is poured to form the base. When the casting is completed the die and the investment are broken away from the casting to leave the latter free. Then I transfer the completed cast metal mesh base to the other die, and from there on I proseed again according to conventional practice, fitting teeth in wax on the cast metal mesh base, now on the second die, then investing the model thus formed in plaster in a flask to form a mold, and then forming a plastic denture in such mold around the teeth and the base to form the completed denture with the cast metal mesh base in place in the denture.
The only novel structural element of my denture is the cast metal mesh base. This is cast from any suitable metal. One metal that I have found suitable in a chromium-cobalt-tungsten alloy which is sold by the Nobilium Processing Co. of Chicago, Illinois, under the trade-mark Nobilium.
The cast metal base reinforces and strengthens the denture, minimizes the danger of breakage, and also prevents warping of the denture.
In dental practice, it is necessary, from time to time, to reline dentures after they have been worn and used for a while to compensate for the shrinkage of the gum or tissue. Relining simply means adding sufficient material to the tissue engaging surface of the denture to make it conform to the shape that the tissue has taken after it has shrunken away from the denture. A denture made with a cast metal mesh base in it, according to my invention, can be relined. However,
the cast metal mesh base improves the bonding between the relining and the denture.
It is important to note that the metal mesh base herein disclosed is cast to a positive die, and thus accurately conforms to the tissue shape, reproduced in that die. In addition, the metal base, a good conductor of heat, aids in curing the plate.
My invention may be applied to all sorts of dentures, to partial dentures as well as to complete dentures, to lower dentures as well as to upper dentures, etc. In all cases, the general shape of the cast metal mesh base will conform to the shape of the denture, regardless of the shape which the denture assumes, and because cast, the base will conform to the tissue shape reproduced in the die.
Now having described my denture and my novel method of making dentures, reference should be had to the-claim which follows.
In the manufacture of dentures, the steps of casting two dies as positive reproductions of the mouth portion for which the denture is being made, forming on one of such dies a wax pattern of a cast metal mesh base, casting on that die from that pattern a cast metal mesh base which by being patterned and cast on that positive die, is shaped to conform to the formation of the tissue of the mouth portion and is rigid and unyielding, removing that cast base from that die and transferring it to the other die, forming on that second die a denture, with that cast base as a base, and with teeth in the denture.
REFERENCES CITED The following references are of record in the file of this patent: