Abstract: PURPOSE: To investigate the influence of dental Co-Cr-Mo alloys on biological behaviour of L929 mouse fibroblasts. METHODS: Leaching liquor of medical pure titanium, Co-Cr-Mo alloys, Co-Cr alloys and Ni-Cr alloys was prepared and used to culture the L929 cells for 24 h, 48 h and 72 h, respectively; then the growth of L929 cells was observed under inverted phase contrast microscope, and the cytotoxicity grades of 4 kinds of materials were evaluated by using CCK-8 test. The apoptosis of L929 cells was measured by flow cytometry(FCM) and acridine orange staining was used to observe the L929 cells adhered on the surface of samples under fluorescent microscope. The data was statistically analyzed with SPSS17.0 software package. RESULTS: Under inverted phase contrast microscope, at each time point, L929 cells grew in a good condition except in the Ni-Cr alloys group that minor karyopyknosis was indicating slight celluar cytotoxicity. Optical density (OD), apoptosis rate and cell adhesion number in Co-Cr-Mo alloys group at each time point were significantly less than in medical pure titanium group (P<0.05), and higher than in Co-Cr alloys group (P<0.05) and Ni-Cr alloys group (P<0.05). During observation period, the cytotoxicity grades of medical pure titanium group, Co-Cr-Mo alloys group and Co-Cr alloys group was grade 1, while Ni-Cr alloy group was grade 2, i.e. mild cytotoxicity. CONCLUSIONS: Co-Cr-Mo alloys have no adverse effect on the biological behavior of L929 cells, which may be suitable for dental clinical application with good biocompatibility.

Key words: Co-Cr-Mo alloy, Cytotoxicity, L929 cells