Cytotoxic Effects Of Self-adhesive Resin Cements Under Different Curing Modes In Vitro

[Purpose]The aim of this study was to evaluate the potential cytotoxic effects of four self-adhesive resin cements(Biscem,RelyX U200,Maxcem and Multilink speed)on human periodontal ligament fibroblasts(HPDLFs)under dual or chemical curing mode.[Methods]Disc-shaped specimens of four 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 being 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(v/v)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.leaching solution about four kinds of resin cements were detected by high performance liquid chromatography(HPLC)separation analysis under different curing modes-The data was statistically analyzed by one-way ANOVA at a significance level of P<0.05.[Results]1.The cytotoxicity and the response values of leaching components during 24 h water storage of Biscem,RelyX U200 and Maxcem under chemical curing mode were significantly higher than that under dual curing mode at any concentration(P<0.05).Only the cytotoxicity and the response values of leaching components during 24 h water storage of Multilink speed had no significant difference under the two kinds of curing mode,showed good biocompatibility.(P>0.05).With the increase of extract concentration,the effect of Cell proliferation inhibition and apoptosis-inducing increased dose-dependently of each experimental group.2.The cell proliferation rates of Biscem,RelyX U200 and Maxcem under chemical curing mode were significantly lower than that under dual curing mode at any concentration(P<0.05).Nevertheless,Multilink speed had no significant difference under the two kinds of curing mode.(P>0.05).Besides,the cell proliferation rates of Biscem and Maxcem 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).Especially Maxcem,with the ratio increase of dilution,the cell proliferation inhibition rapidly reduced.3.The cell early apoptosis rate of four resin cements under chemical curing mode were significantly higher than that under dual curing mode at any concentration(P<0.05).Under the chemical curing mode,the early apoptosis rate of Maxcem in the high concentration group was obviously higher than that of other three materials.When diluted ratio reached 1:40 proportion,the cell early apoptosis rate of Maxcem decreased significantly,there was no significant difference with the other three materials.There is the distinct difference of the cell early apoptosis rate in different materials under dual curing mode.We find that at any concentration,the Multilink speed is weakest,while the Biscem is strongest,In the early induction of cell apoptosis.4.The cell late apoptosis/necrosis rate of Biscem,RelyX U200 and Maxcem under chemical curing mode were significantly lower than that under dual curing mode at any concentration(P<0.05).Nevertheless,Multilink speed had no significant difference under the two kinds of curing mode.(P>0.05)And significantly lower than other three kinds of materials of cell late apoptosis/necrosis rate.Under the chemical curing mode,The late apoptosis/necrosis rate of Maxcem in the high concentration group was obviously higher than that of other three materials.Results the late apoptosis/necrosis rate of Maxcem decreased markedly with the ratio increase of dilution.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.