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US 4,358,549 AGranted
Dental filling composition utilizing zinc-containing inorganic filler
AssigneeMinnesota Mining and Manufacturing Company
InventorRonald M. Randklev
Life of this patent
Estimating the term…
Abstract
This invention is a dental filling composition for making dental restorations. More particularly, the invention provides a radiopaque dental filling material. Specifically, the dental filling material contains a zinc-containing glass as the component imparting opacity to X-rays.
Claims8
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 combined 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.
Dependencies are inferred from the claim text.