Method of making a dental prosthesis

Claim 1

A method of making a dental prothesis from an upper or a lower impression of the oral cavity of a patient, which comprises filling said impression with a castable mixture comprising (1) a ceramic composition containing a major proportion of magnesia and a significant minor proportion of each of alumina and ammonium dihydrogen phosphate, and (2) an aqueous composition containing silica as the essential ingredient, the ratio of the aqueous silica composition to the ceramic composition being such as to render the latter flowable; permitting said mixture to harden in the impression, and removing the resulting hardened model from the impression; selecting from said model the portion requiring said dental prosthesis, effecting drying thereof, and spray-coating a liquefied metal composition on to said selected portion of said model to form a metallic prosthetic base; and separting said metalic prosthetic base from said selected portion of said model and applying a porcelain coating to the exterior surface of said separated metallic prosthetic base to provide said dental prosthesis.

Claim 2

A method of making a dental prothesis from an upper or a lower impression of the oral cavity of a patient, which comprises filling said impression with a castable mixture comprising (1) a ceramic composition containing a major proportion of magnesia and a significant minor proportion of each of alumina and ammonium dihydrogen phosphate, and (2) an aqueous composition containing silica as the essential ingredient, the ratio of the aqueous silica composition to the ceramic composition being such as to render the latter flowable; permitting said mixture to harden in the impression, and removing the resulting hardened model from the impression; selecting from said model the portion requiring said dental prosthesis, effecting drying thereof, and spray-coating a liquefied metal composition on to said selected portion of said model to form a metallic prosthetic base; and separting said metalic prosthetic base from said selected portion of said model and applying a porcelain coating to the exterior surface of said separated metallic prosthetic base to provide said dental prosthesis.

Claim 8

A method of making a dental prosthesis from an upper or a lower impression of the oral cavity of a patient, which comprises filling said impression with a castable mixture comprising (1) a ceramic composition containing magnesia and alumina in a ratio of about 1.4:1 by weight and about 5% by weight of ammonium dihydrogen phosphate, and (2) an aqueous composition containing about 50% silica by weight, the ratio of the ceramic composition to the aqueous silica composition being about 3:1 by weight: permitting said mixture to harden in the impression, and removing the resulting hardened model from the impression; heating the model to a temperature on the order of 400° F. for about 20 minutes, and then cooling the same; selecting the portion of the model requiring said dental prosthesis and spray-coating a liquified metal composition on to said selected portion for a time to form a metallic prosthetic base having a thickness of about 0.5 to 1 mm; cooling the spray-coated selected portion and separating the metallic prosthetic base therefrom; and applying a porcelain coating to the exterior surface of said metallic prosthetic base to provide said dental prosthesis.

Claim 9

A method of making a dental prosthesis from an upper or a lower impression of the oral cavity of a patient, which comprises filling said impression with a castable mixture comprising (1) a ceramic composition containing magnesia and alumina in a ratio of about 1.4:1 by weight and about 5% by weight of ammonium dihydrogen phosphate, and (2) an aqueous composition containing about 50% silica by weight, the ratio of the ceramic composition to the aqueous silica composition being about 3:1 by weight: permitting said mixture to harden in the impression, and removing the resulting hardened model from the impression; heating the model to a temperature on the order of 400° F. for about 20 minutes, and then cooling the same; selecting the portion of the model requiring said dental prosthesis and spray-coating a liquified metal composition on to said selected portion for a time to form a metallic prosthetic base having a thickness of about 0.5 to 1 mm; cooling the spray-coated selected portion and separating the metallic prosthetic base therefrom; and applying a porcelain coating to the exterior surface of said metallic prosthetic base to provide said dental prosthesis.