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

IntroductionThe public interest steadily increases in the biological adverse effects caused by components released from resin-based dental restorations.ObjectiveIn 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).MethodsXTT based cell viability assay was used for cytotoxicity screening of substances. γ-H2AX assay was used for genotoxicity screening. In the γ-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 H2AX. Cell death effects (apoptosis and necrosis), induced by the substances were visually tested by the same investigator using the fluorescent microscope.ResultsAll 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.ConclusionLeached components from dental resin restorations can induce DNA DSBs and cell death effects in HGFs.