Impact of Instrumentation of Curved Mesial Canals in Mandibular Molars with the XP-Endo Shaper and Hyflex

Introduction:This study compared the shaping ability of mesial canals in lower molars using the Hyflex CM and XP-endo Shaper rotary instrumentation systems, utilizing high-resolution computed tomography. Materials and Methods:Thirty-four mesial canals were instrumented and divided into two groups (n = 17): Hyflex CM (HCM) and XP-endo Shaper (XP).A high-resolution computed tomography scan was performed before and after the root canal preparation.The data were analyzed by two trained evaluators.The parameters analyzed included the canal centralization in the cervical, middle, and apical segments, as well as in the entire canal, and the increase in the area at segments 0-3 mm, 0-6 mm, and 0-9 mm from the apex, using the EVOL software.For intragroup and intergroup assessment of the surface area at the three levels, the T-test or Wilcoxon test was used.The ANOVA test was employed for intragroup evaluation of preparation centralization among the three levels. Results:In the flattening region across all segments, both systems showed statistically significant differences intragroup (p < 0.05).Regarding surface area, a statistically significant difference was observed only in the apical segment, where the XP-endo Shaper system resulted in a greater area of wear compared to the preparation provided by the Hyflex system (p = 0.0025). Conclusion:It was concluded that both systems, despite having different instrumentation methodologies and thermal treatments, showed similar outcomes in the instrumentation of curved mesial canals.