Effect of Propolis as a Root Canal Irrigant on Bond Strength to Dentin

Purpose The purpose of this in vitro study was to evaluate the effect of propolis on bond strength to dentin of a self-etch adhesive when used as a final irrigant. Methods 126 human third molars were sectioned 3 mm below the occlusal level and then randomly divided into 7 groups (n = 18). The exposed dentin surfaces were treated with irrigation solutions as follows: Group 1: 5.25% NaOCl; Group 2: 5.25% NaOCl followed by 17% EDTA; Group 3: 5.25% NaOCl followed by Tubulicid Plus (Temrex, Freeport, NY, USA); Group 4: 5.25% NaOCl followed by MTAD; Group 5: 5.25% NaOCl followed by 20% propolis; Group 6: 5.25% NaOCl followed by 2% CHX; Group 7: distilled water (control). Irrigated specimens were bonded using Clearfil SE Bond (Kuraray, Osaka, Japan) with Tygon (Saint-Gobain, Saint-Gobain Performance Plastics, France), tubes for microshear bond strength testing. Data was analyzed using a one-way ANOVA and Tukey test. Results Among the tested groups, although the lowest bond strength values were detected in Group 1 (11.25 ± 1.97), a significant statistical difference was detected only between this group and Group 4 (18.70 ± 1.82) and Group 5 (16.75 ± 3.70) (p = 0.0012). Conclusions 20% propolis solution as a final irrigant was found to have a favorable effect on the dentin bond strength of the tested self-etch adhesive to coronal dentin when compared with other irrigation solutions.