Cytotoxicity and degree of conversion of methacrylate and silorane

Abstract

Composites have been proven to have a cytotoxic effect on a variety of tissues and cells. Aim: The aim of this study was to analyse the degree of conversion of resins and its correlation with the cell viability in primary gingival fibroblasts. Methods: Resin-based silorane (Filtek P90) and conventional methacrylate resins (Filtek Z100, Filtek Z250 and Filtek Z350XT) were used to evaluate cell viability and the degree of conversion. The resins were light-cured by a LED for 20 and 40 seconds. The degree of conversion was analysed by Fourier transform infrared spectroscopy. Cellular metabolism was evaluated after 24 hours by the MTT assay (n = 6) using the storage solution of composite resin for either 24 hours or 12 days. Variance analysis (ANOVA) with a Bonferroni correction (p < 0.05) was performed to compare the groups. Results: The composite Filtek P90 showed a higher degree of conversion when polymerised for 40 or 20 seconds, while the composites Filtek Z100, Filtek Z250 and Filtek Z350XT showed similar degree of conversion. Only the Filtek Z100 resin was cytotoxic. Conclusion: We found no statistically significant correlation between cell viability and the degree of conversion.