Objective To evaluate a new type of diatomite-based machinable ceramic biocompatibility by studying its induced apoptosis on L929 cell in contrasted with other prosthodontics materials. Methods Cell line was treated with extracting liquid containing different concentrations of diatomite-based machinable ceramic and other materials. Flow cytometry tested cell cycle progression and induced cell apoptosis. Annexin V-FITC/PI apoptosis staining kit quantitative detected cell death patterns. The expression of Bcl -2 and Bax mRNA were determined by reverse transcription -polymerase chain raction. Results The experimental groups had no special influence on cell cycle. Apoptosis rates of the new ceramic closed to the negative group（P>0.05）. The apoptosis rate of resin was the highest, and the cell necrosis level of resin was increased, which had significant difference to the new ceramic（P0.05）. Conclusion The new diatomite-based machinable ceramic has no apparent cytotoxicity, which is consistent with the clinical application of the basic requirements of biocompatibility.
