Cytotoxicity and induction of DNA double-strand breaks by components leached from dental composites in primary human gingival fibroblasts

Introduction. The public interest steadily increases in the biological adverse effects caused by components released from resin-based dental restorations. Objective. In this study, the cytotoxicity and the genotoxicity were investigated of following released components from dental resin restorations in human gingival fibroblasts (HGF): tetraethyleneglycol dimethacrylate (TEEGDMA), neopentylglycol dimethacrylate (Neopen), diphenyliodoniumchloride (DPIC), triphenyl-stibane (TPSB) and triphenylphosphane (TPP). Methods. XTT based cell viability assay was used for cytotoxicity screening of substances. gamma-H2AX assay was used for genotoxicity screening. In the gamma-H2AX assay, HGFs were exposed to the substances for 6 h. Induced foci represent double DNA strand breaks (DSBs), which can induce ATM-dependent phosphorylation of the histone H(2)AX. Cell death effects (apoptosis and necrosis), induced by the substances were visually tested by the same investigator using the fluorescent microscope. Results. All tested substances induced a dose-dependent loss of viability in HGFs. Following toxicity ranking among the substances at EC50-concentration were found in the XTT assay (mM, mean +/- SEM; n = 5): DPIC > Neopen > TPSB > TPP > TEEGDMA. DSB-foci per HGF-cell were obtained, when HGFs were exposed to the EC50-concentration of each substance in the following order (mean +/- SEM; n = 3): DPIC > Neopen > TPSB > TPP > TEEGDMA. Multi-foci cells (cells that contain more than 40 foci each) in 80 HGF-cells at EC50-concentration of each substance were found as follow (mean +/- SEM; n = 3): DPIC > Neopen > TPP > TPSB > TEEGDMA. Cell apoptosis contained in each substance at EC50-concentration in the following order (mean +/- SEM; n = 3): DPIC > Neopen > TPSB > TPP >TEEGDMA. Cell necrosis contained in each substance at EC50-concentration in the following order (mean +/- SEM; n = 3): DPIC > Neopen > TPSB > TPP > TEEGDMA. Conclusion. Leached components from dental resin restorations can induce DNA DSBs and cell death effects in HGFs. (C) 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.