| 摘要 |
PURPOSE: To obtain a tooth-filling material which contains, as alloy components, metals forming curable gold alloy and being soluble in nitric acid, and comprises gold alloy powder having the surface layer made of pure gold and the surface roughened. CONSTITUTION: In a tooth-filling material comprising a gold alloy powder, and when necessary, an organic binder for filling tooth cavity by the gold-filling technique, the gold-alloy powder to be used contains, as the alloy components, one to several kinds of noble metals particularly selected from the group consisting of Pd and Ag and base metals selected from Zn, Cu, In and Ga (up to 50% based on the whole metals) generating curable gold alloy and dissolving in nitric acid and has its surface layer made of pure gold (preferably 0.1-2μm thickness) and its surface roughened. A gold alloy powder having the corresponding composition is cured by heat treatment and nitric acid is allowed to act on the powder to form the surface layer comprising surface roughened pure gold. |
