[An experimental study on the biological safety of calcium phosphate glass ceramics]

The cytotoxicity and biological safety of calcium phosphate glass ceramics (CPGC) blocks and powders were examined. CPGC blocks were implanted in the femur, muscle and subcutaneous tissue, and CPGC powders in the medullary cavity, joint, subcutaneous tissue and the abdominal cavity of rats. These rats were sacrificed one or two years after implantation, specimens were examined histologically, and the CPGC blocks were found to have good compatibility not only with bone but with subcutaneous tissue and muscle. Neither inflammatory cells nor foreign body giant cells were observed in the vicinity of the CPGC powders in the medullary cavity. Neither was there any chronic toxicity, carcinogenicity or teratogenicity, thus clearly demonstrating the high biological safety of CPGC. A culture of L-929 cells and cells derived from human subcutaneous tissue around CPGC blocks or powder indicated the rates of their cellular adhesion and proliferation to be good. No findings indicating cytotoxicity were observed in the specimen of CPGC by the cultured cell method.