Purpose: In this ex vivo study, the surface cleanliness of root canal walls after shaping with Ni-Ti instruments and irrigating with different endodontic solutions was evaluated by SEM.
Methods: 50 single-rooted teeth were divided into 5 groups. All root canals were shaped with Revo-S™ (MICRO-MEGA®, Besancon, France) rotary Ni-Ti instruments and irrigated with NaOCl, varying the final rinse: NaOCl, Tetraclean, 17% EDTA, Cloreximid, Tetraclean liquid not mixed with powder. Specimens were fractured longitudinally and prepared for SEM analysis in order to evaluate the presence/absence of smear layer and the presence/absence of open tubules at the coronal, middle, and apical third of each canal, using a 3-step scale for scores. Numeric data were analyzed using Kruskall-Wallis test and Mann-Whitney U test and significance was predetermined at p<0.05.
Results: This study showed significant differences between the various groups. The 5.25% NaOCl + Tetraclean and 5.25% NaOCl + 17% E.D.T.A. groups had significantly lower scores than other groups (p<0.001), with no significant difference between them.
Conclusions: Final rinse with Tetraclean is effective in removing the smear layer, leaving a high number of opened dentin tubules.