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US 4,431,451 AGranted
Dental material
AssigneeAmerican Dental Association Health Foundation
InventorsCurtis P. Mabie, Daniel L. Menis
Life of this patent
Estimating the term…
Abstract
Dentures, dental glazes or coatings, reconstructive jacket-crowns and inlays and restorative constructions over metal or preformed alumina substrates are fabricated from a dental porcelain frit prepared by a gel route.
Claims28
A method of preparing a dental porcelain article which comprises preparing a dental porcelain frit by the process comprising:
- (a) preparing a sol comprising in weight percent based on total solids content, 55-80% silica, 5-20% alumina, 12-40% flux constituents, and 0-7% additives, the 12-40% flux constituents comprising the solubilized oxides of boron, sodium, potassium, and lithium, the 0-7% additives comprising the solubilized oxides of calcium, magnesium, barium, strontium, zinc, tin, phosphorus, cesium, rubidium, yttrium, ytterbium, samarium, lanthanum, titanium, zirconium, terbium, thulium, cerium, europium and scandium with no single additive being present in an amount greater than 4%,
- (b) gelling the sol, and
- (c) calcining the gelled sol by heating it to calcination temperature to form a calcined frit, the frit being characterized by minimal microporosity and by a fusion temperature of 960.degree. C. or less,
- and then comminuting the frit, forming it into a dental porcelain article and firing it.
1 more element
A method of preparing a dental porcelain article which comprises preparing a dental porcelain frit by the process comprising:
- (a) preparing a sol comprising in weight percent based on total solids content, 55-80% silica, 5-20% alumina, 12-40% flux constituents and 0-7% additives, the 12-40% flux constituents comprising solubilized oxides of boron, sodium, potassium, and lithium, the 0-7% additives comprising the solubilized oxides of calcium, magnesium, barium, strontium, zinc, tin, phosphorus, cesium, rubidium, yttrium, ytterbium, samarium, lanthanum, titanium, zirconium, terbium, thulium, cerium, europium and scandium with no single additive being present in an amount greater than 4%,
- (b) gelling the sol,
- (c) precalcining the gelled sol by heating it at a moderate temperature,
- (d) comminuting the heated, gelled sol, and
- (e) calcining the comminute at a higher temperature to form a calcined frit, the frit being characterized by minimal microporosity and by a fusion temperature of 960.degree. C. or less,
- and then recomminuting the frit, forming it into a dental porcelain article and firing it.
3 more elements
A dental porcelain frit prepared by the method comprising:
- (a) preparing a sol comprising in weight percent based on total solids content, 55-80% silica, 5-20% alumina, 12-40% flux constituents, and 0-7% additives, the 12-40% flux constituents comprising solubilized oxides of boron, sodium, potassium, and lithium, the 0-7% additives comprising the solubilized oxides of calcium, magnesium, barium, strontium, zinc, tin, phosphorus, cesium, rubidium, yttrium, ytterbium, samarium, lanthanum, titanium, zirconium, terbium, thulium, cerium, europium and scandium with no single additive being present in an amount greater than 4%,
- (b) gelling the sol,
- (c) precalcining the gelled sol by heating it at a moderate temperature,
- (d) comminuting the heated, gelled sol, and
- (e) calcining the comminute at a higher temperature to form a calcinate, the calcinate being characterized by minimal microporosity and by a fusion temperature of 960.degree. C. or less.
2 more elements
Dependencies are inferred from the claim text.