An Analytical Study of the Inflammation Induced by a Calcium Phosphate Ceramic

The acute toxicity of apatite-wollastonite glass ceramic was investigated in C57BL/6, C3H and A/J mice. The LD50 value of apatite-wollastonite glass ceramic after intraperitoneal administration in C57BL/6 mice was 750mg/kg. The death induced by the material was also observed in C3H (H-2k) and A/J (H-2a). It is suggested that the lethal response to apatite-wollastonite glass ceramic was not controlled by genes located within the major histocorpatibility complex.Mice were died from two to six days after administration of apatite-wollastonite glass ceramic. The death was induced by the ceramic powder itself, and was not induced by the supernatant of the ceramic powder. The delayed-type hypersensitivity response to the material was studied by utilizing the footpad assay in C57BL/6 mice. Significant footpad swelling was observed in mice challenged with apatite-wollastonite glass ceramic over a week after challenge. The lethality of the material administered weekly was not changed during five weeks. These results suggest that an inflammation of a special sort, not an immunological one, played an important role in the lethal reaction. It may be suggested that the possible toxicity of the apatite-wollastonite glass ceramic appears in human beings.