PURPOSE: To obtain the titled composition having excellent biocompatibility, and integrable with the dental tissue, by calcining a mixture of dibasic calcium phosphate and calcium carbonate at a specific molar ratio, and adding barium sulfate, calcium hydroxyapatite and a kneading liquid to the calcined product.

CONSTITUTION: Dibasic calcium phosphate of formula CaHPO4 or its dihydrate of formula CaHPO4-2H2O is mixed with calcium carbonate at a molar ratio of 2:1, and the mixture is calcined and pulverized to fine powder. The objective fluid or plastic composition for filling a dental cavity can be produced by mixing the above powder with a kneading liquid composed of barium sulfate, calcium hydroxyapatite, and water, physiological saline water, aqueous solution of polyacrylic acid, aqueous solution of acrylic acid-itaconic acid copolymer, or their mixture.