| 摘要 |
A dental restoration comprises a porcelain-covered body of a non- precious metal alloy which includes 58-68% nickel, 18-23% chromium, 6-10% molybdenum, 0.01 to 5% of at least one rare-earth element, 1 to 4% columbium plus tantalum, up to 2% iron, and lesser quantities of carbon, aluminum, titanium, silicon and manganese. The alloy is resistant to corrosion by mouth fluids, is easy to finish and polish, and is closely matched to the thermal-expansion properties of commercially available dental porcelains. The alloy does not contaminate alloy-melting crucibles, exhibits excellent bonding characteristics to dental porcelains, is easy to melt and cast, and has sufficient ductibility to enable margin burnishing of dental-restoration castings of the alloy. |
