Evaluation of Cytotoxicity of Silorane and Methacrylate based Dental Composites using Human Gingival Fibroblasts

Aim: The effects of leached substances from the restorative dental materials may induce local and systemic adverse effects. Thus the biological and toxic properties of the restorative dental materials must be compatible with the oral tissues or with general health. Therefore, the need for biocompatible restorative dental material implies the necessity of toxicity testing. It was the purpose of this investigation to determine and compare the possible toxic effect of silorane based composite (Filtek P90) on human gingival fibroblast (HGF) in vitro using cytotoxicity measuring parameters (MTT assay) in comparison with its methacrylate counterpart (Z100) for their viability, proliferation rate. Materials and Methods: Fresh healthy biopsy specimens of human gingival tissue of patients were obtained. For HGF, cells were cultured in Dulbecco's modified Eagle medium and grown to sub confluent monolayers. After attaining confluence, cells were treated with different doses of the Filtek P90 or Z 100 for different time point. HGF cells were observed for their proliferation, viability by MTT assay. Results: The results of the cytotoxicity assay showed that, the percentage of viable cells was very good in the first 24h and marginally decreased in the next 48h period in all groups. However, the proliferation rate was never below 84% in all the groups, at any given concentration. Filtek P90 and Z100 treated cells exhibited insignificant decrease in the cell proliferation both in 24h and 48h exposure when compared to significant decrease in the cell survival rate in the positive control (Mitomycin C 250 mu g/ml).) Comparison of the toxicity between Filtek P90 and Z100 in 24h & 48h separately showed that there was no significant difference (p<0.05) between these two composites in 24h and 48h' time period at all concentrations of the composites. Conclusion: To conclude, the new silorane based restorative composite showed comparable cytotoxic characteristics to clinically successful dimethacrylate composites suggesting the non- toxic nature in the oral environment and hence contributing to clinical success of these new restorative materials.