Cleaning and Shaping Oval Canals with 3 Instrumentation Systems: A Correlative Micro-computed Tomographic and Histologic Study

Introduction: The present study evaluated the cleaning and shaping ability of 3 instrumentation systems in oval canals of extracted vital teeth using a correlative analytic approach. Methods: Oval distal canals from 33 freshly extracted mandibular molars with pulp vitality were scanned by micro computed tomographic (micro-CT) imaging for sample selection. Specimens matched by anatomic similarities were distributed into 3 experimental groups according to the instrument system to be evaluated: the Self-Adjusting File (SAF; ReDentNOVA, Ra'anana, Israel), TRUShape (Dentsply Sirona, Tulsa, OK), and XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland). The irrigant was 5.25% sodium hypochlorite heated at 37 degrees C. After rescanning with micro-CT imaging, the unprepared surface areas were identified, measured, and then histologically evaluated for the amount of pulp remnants in each root third. Results: When the apical 4-mm canal segment was evaluated, the SAF exhibited significantly less unprepared areas than the XP-endo Shaper (P<.05), and there were no significant differences for the other comparisons (P>.05). Analysis of the full canal length showed no statistically significant differences between the 3 tested systems (P>.05). Likewise, the tested systems did not differ significantly in cleaning the unprepared walls (P>.05). Conclusions: There was no significant difference in the amount of unprepared surface areas between the 3 instrument systems, except for the comparison between the SAF and XP-endo Shaper in the apical 4-mm segment. None of them prepared 100% of the root canal walls. The cleaning ability of the 3 systems was similar.