The Effect of Chlorhexidine on Push-out Bond Strength of Mineral Trioxide Aggregate

Background: Trioxide Aggregate (MTA) has been widely used in root canal therapy. MTA has been mixed with chlorhexidine to increase its antimicrobial effect. Objectives: The aim of this study was to evaluate the effect of chlorhexidine (۲%) on push-out bond strength of Mineral Trioxide Aggregate (MTA). Materials and Methods: Sixty dentin disks with a thickness of ۱.۵ ± ۰.۲ mm and lumen size of ۱.۳ mm were prepared. Dentin disks were randomly divided into four groups (n = ۱۵), and their lumens were filled with MTA mixed with distilled water (groups ۱ and ۳) or with chlorhexidine ۲% (groups ۲ and ۴). Specimens were incubated at ۳۷°C for ۳ days (groups ۱ and ۲) or ۲۱ days (groups ۳ and ۴). Bond strengths of the MTA-treated dentin surfaces were evaluated using a universal testing machine, and bond failure on the disks was examined by light microscope. Data was analyzed using Kruskal-Wallis H test (P = ۰.۹۷۶). Results: There were no statistically significant differences between all the experimental groups. The mode of bond failure was predominantly mixed for distilled water groups and cohesive for CHX groups. Conclusions: This study suggested that chlorhexidine had no negative effect on the bond strengths of MTA-treated dentin.