Effect of Light Irradiation on Cytotoxic of Self-adhesive Resin Cements

Objectives: The aim of this study was to evaluate the potential cytotoxic effects of self-adhesive resin cements on human periodontal ligament fibroblasts (HPDLFs) with or without light irradiation.
Methods: The extract solution of four self-adhesive resin cements (Biscem , RelyX U200, Maxcem and Multilink Speed) with or without light irradiation was diluted accordingly to 1:5, 1:10, 1:20, 1:40, 1:80 (v/v) with complete DMEM. HPDLFS were cultured in the diluted solutions for 24h. Complete DMEM without specimen immersed was used as negative control. 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.
Results: With the increase of extract concentration, the effect of cell proliferation inhibition and apoptosis-inducing increased dose-dependently of all resin cements. The cell early apoptosis rate of four resin cements with light irradiation were significantly higher than that without light irradiation at any concentration (P<0.05). Cements’ extracts without light irradiation inhibited cell proliferation and induced late apoptosis/necrosis significantly than that with light irradiation at any concentration (P<0.05) except for Multilink Speed. No matter light irradiation or not, Multilink Speed showed the best biocompatibility concerning cell proliferation and cell apoptosis induction. Maxcem without light irradiation showed the highest cytotoxic effects, however with light irradiation could obtain similar biocompatibility with Multilink Speed. Without light irradiation, Biscem showed higher cytotoxic effect than Rely X U200, and with light irradiation, Biscem and Rely X U200 showed similar effects on cell proliferation.
Conclusions: The composition difference and light irradiation of self-adhesive resin cements could affect their biocompatibility concerning cell proliferation and cell apoptosis induction of HPDLFs.