Dental filling composition utilizing zinc-containing inorganic filler

Claim 2

A dental filling composition comprising a polymerizable resin binder and a finely divided inorganic glass filler which is X-ray opaque and single phase, wherein said X-ray opaque inorganic glass filler consists essentially of, in percent by weight: ______________________________________ Zinc oxide 20 to 35% Silica 45 to 65% Boric oxide 3 to 15% Aluminum oxide 0 to 10% Aluminum fluoride At least 2% Alkali metal oxide or 0 to 3% alkaline earth metal oxide ______________________________________ wherein the compound weight of aluminum oxide and aluminum fluoride is at least about 10%, and wherein said glass exhibits an X-ray absorption characteristic of at least 1/16 inch.

Claim 3

A composition in accordance with claim 1, wherein said binder comprises a free-radically polymerizable resin.

Claim 4

A composition in accordance with claim 2, wherein said polymerizable resin binder comprises BIS-GMA.

Claim 5

A composition in accordance with claim 1, wherein the index of refraction of said glass filler and said resin are substantially the same.

Claim 6

A composition in accordance with claim 1, wherein said composition is in the form of two pastes, the first said paste comprising polymerizable resin binder, inorganic glass filler, and a catalyst, and the second said paste comprising polymerizable resin binder, inorganic glass filler, and an accelerator.

Claim 7

A composition in accordance with claim 5, wherein said filler represents at least about 70% by weight of each said paste.

Claim 8

A composition in accordance with claim 5, wherein said binder in each said paste comprises BIS-GMA.

Claim 9

A composition in accordance with claim 3, wherein said glass filler consists essentially of, in percent by weight: ______________________________________ Zinc oxide 25 to 28% Silica 46 to 48% Boric oxide 6 to 9% Aluminum oxide 1 to 3% Aluminum fluoride 17 to 19% ______________________________________ wherein the combined weight of aluminum oxide and aluminum floride is not greater than about 20%. .Iadd.9. A dental filling composition comprising a polymerizable resin binder and a finely divided inorganic glass filler which is X-ray opaque and single phase, wherein said X-ray opaque inorganic glass filler consists essentially of, in percent by weight: ______________________________________ .Iadd.Zinc oxide 20 to 35% Silica 45 to 65% Boric oxide 3 to 15% Aluminum oxide combined weight of at least about 10% Aluminum fluoride Alkali metal oxide or 0 to 5% alkaline earth metal oxide ______________________________________ .Iaddend. wherein the weight of aluminum floride is sufficient to contribute to the melt fluidity of the glass and enable it to be poured in the form of thin filaments for rapid cooling thereof, and wherein said glass exhibits an X-ray absorption characteristic of at least 1/16 inch. .Iadd.10. A composition in accordance with claim 9, wherein said combined weight of aluminum oxide and aluminum fluoride is not greater than about 20%. .Iaddend. .Iadd.11. A composition in accordance with claim 9, wherein said binder comprises a free-radically polymerizable resin. .Iaddend. .Iadd.12. A composition in accordance with claim 11, wherein said polymerizable resin binder comprises BIS-GMA. .Iaddend. .Iadd.13. A composition in accordance with claim 9, wherein the index of refraction of said glass

Claim 10

filler and said resin are substantially the same. .Iaddend. .Iadd.14. A composition in accordance with claim 9, wherein said filler comprises 80-90% of the weight of said composition. .Iaddend. .Iadd.15. A dental filling composition comprising a polymerizable resin binder and a finely divided inorganic glass filler which is X-ray opaque and single phase, wherein said X-ray opaque inorganic glass filler consists essentially of, in percent by weight: ______________________________________ .Iadd.Zinc oxide 20 to 35% Silica 45 to 65% Boric oxide 3 to 15% Aluminum oxide 0 to 10% Alkali metal oxide or 0 to 5% alkaline earth metal oxide ______________________________________ .Iaddend. and aluminum fluoride, wherein the combined weight of aluminum oxide and aluminum fluoride is at least about 10%, the weight of aluminum oxide is sufficient to contribute to the melt fluidity of the glass and enable it to be poured in the form of thin filaments for rapid cooling thereof, and said glass exhibits an X-ray absorption characteristic of at least 1/16 inch. .Iadd.16. A composition in accordance with claim 15, wherein said combined weight of aluminum oxide and aluminum fluoride is not greater than about 20%. .Iaddend. .Iadd.17. A composition in accordance with claim 15, wherein said binder comprises a free-radically polymerizable resin. .Iaddend. .Iadd.18. A composition in accordance with claim 17, wherein said polymerizable resin binder comprises BIS-GMA. .Iaddend. .Iadd.19. A composition in accordance with claim 15, wherein the index of refraction of said glass filler and said resin are substantially the same. .Iaddend. .Iadd.20. A composition in accordance with claim 15, wherein said filler comprises 80-90% of the weight of said composition. .Iaddend.