Abstract: Objective To evaluate the potential cytotoxic effects of two self-adhesive resin cements (Biscem and RelyX U200) on human periodontal ligament fibroblasts (HPDLFs) under dual or chemical curing mode. Methods Disc-shaped specimens of two self-adhesive resin cements were prepared under dual or chemical curing mode and incubated for 24 hours in the dark. Then specimens were immersed in complete DMEM (Dulbecco’s Modified Eagle Medium, supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin) for 24 hours (37 ℃ and 5% CO2). After filtered through a sterile 0.22/μm syringe filter, the extract solution was diluted accordingly to 1︰5, 1︰10, 1︰20, 1︰40, 1︰80 with complete DMEM. The diluted solutions were considered as experimental groups and complete DMEM without specimen immersed was used as negative control. All the groups were co-cultured with human periodontal ligament fibroblasts for 24 hours. Then the morphology and amount of cells were observed under the microscope. The cell proliferation rates were detected by Cell Counting Kit-8. Besides, the cell apoptosis was measured by Annexin V-FITC and PI staining using a flow cytometry-based method. The data was statistically analyzed by one-way ANOVA at a significance level of P＜0.05. Results The cell proliferation rates of two resin cements under chemical curing mode were significantly lower than that under dual curing mode at any concentration (P＜0.05). Besides, the cell proliferation rates of Biscem under chemical curing mode were significantly lower than the value of RelyX U200 under chemical curing mode (P＜0.05). Nevertheless, under dual curing mode, no significant difference was found between Biscem and RelyX U200 (P＞0.05). Two resin cements both showed that the apoptosis rates under chemical curing mode were significantly higher than the value under dual curing mode (P＜0.05). And the apoptosis rates of Biscem were significantly higher than RelyX U200 regardless of curing mode (P＜0.05). Conclusions The cell proliferation rate and apoptosis rate of human periodontal ligament fibroblasts can be influenced by the type of self-adhesive resin cements and their curing mode.

Key words: [Keywords] Self-adhesive resin cements , Curing mode , Human periodontal ligament Fibroblasts , Cytotoxicity