Osteogenic cell cytotoxicity and biomechanical strength of the new ceramic Diopside

Diopside was prepared by sintering a powder compact composed of CaMgSi2O6 at 1573K for 2 h. In order to clarify the biocompatibility of Diopside, the cytotoxicity of Diopside against the osteogenic cell line MC3T3-E1 and the bone-Diopside interface strength were examined. On both the 14th and 21st days of incubation of MC3T3-E1 cells with Diopside, ALP activities were not significantly lower than those of the CTRL. TEM photographs of MC3T3-E1 on Diopside after 14 days of incubation showed active secretion of crystals from osteoblast-like cells. Scanning electron microscopic analysis showed that the cells on Diopside formed multiple cell layers similar to those on the CTRL both 14 and 21 days after incubation. These results showed that Diopside had no cytotoxic effect on MC3T3-E1. The pulling test showed that failure loads of Diopside were significantly lower than those of AWGC. Histologically, there was no fibrous tissue or foreign body reaction at the bone interface. SEM-EPMA showed that Diopside had attached to the bone via a calcium-phosphorus layer. SEM back-scattered electron imaging showed that the Diopside plate had degraded to a porous state 12 weeks after implantation. These findings indicate that Diopside is a biodegradable ceramic.