IMMORTALIZED MOUSE ODONTOBLAST CELL-LINE M06-G3 APPLICATION FOR IN-VITRO BIOCOMPATIBILITY TESTING

Purpose: This study was designed to determine the usefulness of an est ablished stable immortalized mouse odontoblast cell line (MO6-G3) for dental material biocompatibility testing. Using a standard toxicity as say based on cell respiratory activity, the response of MO6-G3 cells w as compared to the mouse fibroblastic cell line, L929, presently used for dental materials testing. The dental resin monomer TEGDMA was used as the dental material for the assay. Materials and Methods: Cell lin es (1 x 10(3)/well) were plated in 96 well. culture plates and grown i n DMEM supplemented with 10% FCS, 100 units/ml each of penicillin and streptomycin, and 50 mu g/ml ascorbic acid in an atmosphere of 95% air and 5% CO2. Cells were exposed to TEGDMA resin monomer covering a dos e range of 1 x 10(-6) to 0.5 x 10(-3) M. Unexposed control cells, as w ell as cells exposed to the DMSO vehicle in which the TEGDMA was disso lved, were included in all assays. Cytotoxicity was evaluated by deter mining cell respiratory activity spectrophotometrically using the tetr azolium compound WST-1. Results: Statistical analysis by ANOVA using T ukey's method for pair-wise comparisons as the post hoc test indicated toxic effects of TEGDMA at 1 x 10(-5) M in the odontoblast cell line MO6-G3. By contrast, the monomer produced no toxic effects on the L929 fibroblast cell line after 24 hours of exposure, over the entire conc entration range tested. Furthermore, MO6-G3 cells exposed to a concent ration of 0.5 x 10(-3) M were unable to recover from the effects of th e exposure 48 hours after removal of the resin. MO6-G3 cells exposed t o 1 x 10(-4) and 0.5 x 10(-4) TEGDMA recovered 40-50% and 75-80% of co ntrol respiratory activity respectively, 48 hours after removal of the resin. Respiratory activity by L929 cells exposed to all TEGDMA conce ntrations tested was not different from the vehicle control 48 hours a fter removal of the resin.