Mandana Naseri - Department of Endodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Yazdan Shantiaee - Department of Endodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Babak Zandi - Department of Endodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Alireza Norouzi - Dentist, Private Practice.
Seyeddavood Sadeghi - Department of Endodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Leila Eftekhar - Department of Pedodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Objective: This study aimed to evaluate the cleaning efficacy of different rotary systems during root canal treatment.Methods: Forty-five extracted mandibular molars were randomly divided into three groups according to the rotary system applied: Group ۱, EDMax; Group ۲, EdgeFile X۱; and Group ۳, Neoniti. The samples were irrigated with ۵.۲۵% NaOCl and normal saline as the final rinse. Roots were sectioned longitudinally and examined under scanning electron microscopy (SEM). The debris and smear that remained in the root canals were assessed using a five-score index and compared between groups and root sections. The statistical analysis was performed by Kruskal-Wallis, Friedman, Wilcoxon Signed Ranks, and Mann-Whitney U tests at P < ۰.۰۵.Results: There was a statistically significant difference in debris scores between groups at the apical third (P=۰.۰۰۳), but no significant difference was found in other root sections (P>۰.۰۵). The sequential rotary EDMax group had more apical debris compared to the single-file reciprocating EdgeFile X۱ and single-file rotary Neoniti groups (P< ۰.۰۵). No significant difference was observed between the study groups in smear layer scores (P>۰.۰۵). However, the smear layer score was significantly greater in the apical than in other root sections in all groups (P<۰.۰۵).Conclusions: The single-file systems, Neoniti and EdgeFile X۱, demonstrated superior cleaning efficacy compared to the sequential EDMax system in the apical third, whereas the efficacy of all systems was equivalent in other root areas. Single-file systems may be more effective for root canal cleaning, especially in areas that are more difficult to access.

Debridement, Root canal preparation, Rotary file, scanning electron microscope, Single file system, smear layer