Efficacy of irrigants on smear layer removal in root canals

Irrigation solutions are used with antibacterial purpose and debris removal in root canals improving the instrumentation and promoting better action of intracanal medication. Objectives: The purpose of this study was to verify the debris removal by sodium hypoclorite (NaOCl) and chlorexidine after instrumentation of root canal. Methods: Thirty-six single-rooted human teeth were divided into three groups (n=12): group A, irrigated with Canal + ® (Septodont) (3mL) for 2 min, followed by 0.5% NaOCl for 2 min; group B, 2.5% NaOCl (3mL) for 2 min and group C, 2% chlorexidine gel (3mL) for 2 min, followed by physiologic saline solution for 2 min. The teeth were instrumented using a step-back technique until #35 file and were enlarged with Gattes-Glidden 2 and 3. A final flush in groups B and C was made with 17% EDTA applied by 3 minutes. SEM evaluations were made in the cervical, middle and apical thirds, with 2000X magnifications. The number of open dentin tubules were evaluated on standard area, and values were statistically analyzed using ANOVA and Tukey's tests (p<0.05). Results: There were no significant statistical differences between the number of open dentin tubules in groups (p=0.09). However, was verified that apical third (1.33) presented a smaller number of open dentin tubules than middle (10.85)and cervical (15.85)thirds (p=0.01). Conclusions: In conditions in that this study was applied the irrigation solutions were less effective on apical third cleaning than that on cervical and middle thirds.