Introduction: The present study aimed to compare the smear layer removal and cleaning abilities of the ProTaper Next (PTN), One Shape (OS), and XP Shaper rotary NiTi systems.
Materials and Methods: Thirty single-rooted, freshly extracted teeth were selected for this study. Three NiTi file systems were used for mechanical preparation: ProTaper Next files, one shape single file, and an XP Shaper file. The teeth were divided into three groups. In group 1, teeth were prepared in ProTaper Next files; in group 2, teeth were prepared in one shape file; and in group 3, teeth were prepared in an XP Shaper file. Irrigation was carried out with 5.25% NaOCl and 17% ethylenediaminetetraacetic acid (EDTA). The teeth were longitudinally split into two halves and prepared for evaluation via Scanning Electron Microscope. The presence/absence of the smear layer and the presence/absence of debris at the coronal, middle, and apical thirds of each canal were evaluated via two 5-step scales for scoring. Numeric data were analyzed via the F-test (ANOVA) for normally distributed quantitative variables and the Post Hoc test (Tukey) for pairwise comparisons.
Results: A statistically significant difference was detected among the three groups. XP-endo Shaper files showed the best debris and smear layer removal.
Conclusions: the XP Shaper files presented the best smear layer and debris removal in the coronal, middle, and apical thirds of the root canal compared with those of the other two groups. One-shape single files resulted in less smear layer removal than did the ProTaper multiple file system