Evaluation of the in vitro biocompatibility of various elastomers

A previous study highlighted the superior shock absorption of silicone rubb ers compared to other elastomers. We evaluated and compared the in vitro bi ocompatibility of silicone-based rubbers and propose them as an alternative to conventional products. We used the MTT colorimetric test to assess cell viability and flow cytometry to evaluate cell proliferation. Tests were co nducted at 24 and 72 h. Changes in cell morphology were evaluated by scanni ng electron microscopy. Positive (polyurethane) and negative (polystyrene) toxicity controls were included. The number of viable cells was significant ly higher on polystyrene than on polyurethane. A decrease in the total numb er of cells from 24 to 72 h compared to the negative control was correlated with a lower percentage of S-phase cells. The differences in cell viabilit y noted between the samples and the polystyrene control mainly resulted fro m an initial lack of adhesion, which was confirmed by scanning electron mic roscopy. The biocompatibility of the three silicone rubbers was comparable to the best of the three products currently being used. These results, comb ined with those of the previous study, indicate that silicone rubber could be considered for the manufacture of mouth guards. (C) 1999 Published by El sevier Science Ltd. All rights reserved.