Evaluation Of The Quality Of The Apical Sealing And Toxicity Of Three Root Canal Sealers In Vitro

Objective : To compare the quality of the apical sealing and Toxicity of methacrylate resin-based root canal sealers EndoREZ and AHplus with Zinc Oxide-eugenol paste.Methods:Sixty-four single rooted human anterior teeth were ins- trumented and randomly divided into three experimental groups(A,B,C)of 20 teeth each and two control groups(D,E)of 2 teeth each. Group A was filled with laterally condensed gutta-percha using EndoREZ as sealer. Group B was filled with laterally condensed gutta-percha using AHplus as sealer. Group C was filled with laterally condensed gutta-percha using zinc oxide eugenol as sealer. Group D was the positive control. Group E was the negative control, teeth were demineralized dehydrated and cleared..Apical microleakage was measured by dye penetration.Mouse fibroblast L-929 cells were cultured in the medium of extraction of the three root canal sealers respectively for 2,24,72 hours. The morphologic change of the cells were observed by the inverted phase contrast microscope. Cell growth was tested by MTT assay and the cell relative growth rate (RGR) was calculated. The cytotoxicity was graded by generally accepted standard.Results:There was statistically significant difference from group A and group B,C(P<0.01),and there was no statistically significant difference between group A and B(P>0.05).When the cells were cultured in the medium of extraction of the three root canal sealers respectively for 2h, there was statistically significant difference from group A,B,C and control group (P<0.01). and there was no statistically significant difference between group A and control group(P>0.05).For 24h and 72h, there was no statistically significant difference from group A,B,C and control group .EndoREZ were rated nontoxic,anoter two groups were rated severely toxic. zinc oxide-eugenol was rated more toxic than AHPlus.But when set ,the three root canal sealers were rated notoxic.Conclusions:The ability of apical sealing of EndoREZ and AHPlus was better than that of Zinc Oxide-eugenol paste. No difference is found between EndoREZ and AHPlus in their apicalsealing ability.EndoREZ were rated nontoxic, AHPlus and Oxide-eugenol paste were rated low-grade toxic. zinc oxide-eugenol was rated more toxic than AH- Plus.But when set ,the three root canal sealers were rated notoxic.