Investment casting process of chromium-cobalt and/or nickel alloys

In an investment casting process for producing dental restorations having excellent dimensional accuracy and excellent surface smoothness by the steps of fixing a wax pattern onto a truncated cone in a metallic ring having a lining of a cushioning material, pouring an investment material into the space around the wax pattern in the metallic ring, drying the resultant product, melting out the invested wax pattern, curing the resultant product to give a mold, fixing the mold to a centrifugal casting machine and casting a molten chromium-cobalt and/or nickel alloy in the mold, wherein the improvement comprises curing the mold by heating it at a temperature of 700.degree. to 950.degree. C for 20 to 150 minutes and centrifugally casting the alloy while maintaining the temperature of the mold at 100.degree. to 500.degree. C.