Comparative Evaluation of the Effect of Sodium Thiosulfate Versus Proanthocyanidin as Final Irrigants on the Bond Strength of Epoxy Resin Sealer to Root Dentin Treated With Sodium Hypochlorite (A Comparative in-Vitro Study)

Abstract

Aim: Comparing the effect of Proanthocyanidin and Sodium thiosulfate solutions as final irrigants on the push-out bond strength of epoxy-resin sealer to sodium-hypochlorite-treated root dentin and studying the physicochemical properties of both solutions for potential routine use. Subjects and methods:Thirty-three single-rooted extracted teeth were decoronated and mechanicallyprepared using rotary NiTi instruments and irrigated with 2.5% sodium hypochlorite. Samples were randomly allocated into three groups according to the final irrigant: group1(control), Saline; group2, 6.5% proanthocyanidin, and group3, 5% sodium-thiosulfate. All samples were obturated using gutta-percha and AH-plus epoxy-resin sealer and then cross-sectioned and subjected to push-out bond strength test at different root levels. For physicochemical evaluation, a sample of each experimental irrigant was tested for surface tension using the du-Noüy-ring method via force-tensiometer. Viscosity was tested using a rotational digital viscometer and pH was measured using a benchtop pH-meter.Statistical analysis was performed using one-way ANOVA test followed by Tukey's post-hoc test for intergroup comparisons. Repeated measures ANOVA followed by Bonferroni post-hoc test were used for intragroup comparisons. The significance level was set at p ≤ 0.05.Results: Proanthocyanidin-treated group showed -significantly-the highest mean push-out bond strength values (~1.58 MPa) compared to other groups. Proanthocyanidin solution showed significantly lower mean surface tension (46.71 mN/m) and viscosity (37.43 KU). Sodium-thiosulfate showed a slightly alkaline pH (~8.2), while proanthocyanidin showed a slightly acidic pH (~5.8). Conclusions:Proanthocyanidin solution can improve the bond strength of epoxy-resin sealer to sodiumhypochlorite-treated dentin. It also showed favorable physicochemical properties that make it promising for routine endodontic use.