Introduction. This study aimed at evaluating the influence of isopropyl alcohol drying on the push-out bond strength of different endodontic sealers to root canal dentin. Materials and methods. 60 single-rooted premolars were endodontically prepared up to size X3 ProTaper Next rotary file in the presence of 17% EDTA lubricant and 2.52% NaOCl irrigation. The prepared root canals were finally dried with absorbent paper point after flushing with NaOCl (Group 1, n=30) and 70% Isopropyl Alcohol (Group2, n=30). The dried root canals in each group were then obturated in 3 subgroups (n=10) using singlecone gutta percha and ZOE (PulDent, SG1), Ca(OH)2 (Apexit Plus, SG2) and epoxy resin-based (Adseal, SG3) sealers. Horizontal 2 mm thick sections were then obtained from the cervical and middle thirds of each root, to test the push-out bond strength of the utilized sealer to root canal dentin on a universal testing machine. The mode of failure in each specimen was also assessed. Both 2-Way ANOVA and Tukey’s tests at α=0.05 were used to check the significance of differences between subgroups. Results and discussion. Adseal of SG3 showed the highest bond strengths to root canal dentin in both test groups (p<0.05). Intracanal isopropyl alcohol drying reduced the bond strength of both PulpDent and Apexit in SG1 and SG2 to root canal dentin (P<0.05). On the contrary, it improved the bond strength of Adseal in SG3 (P<0.05). The mixed mode of bond failure was dominant in all subgroups. Conclusions. Extra root canal drying with 70% isopropyl alcohol adversely affects the bond strength of both ZOE and Ca(OH)2-based sealers to root canal dentin, although the same procedure seemed beneficial to the bond strength of epoxy resin-based sealers.
Keywords:- alcohol
- bond strength
- drying
- endodontic sealer
- push-out.