Shaping ability of two root canal instrumentation systems in oval-shaped canals: A microcomputed tomography study.

The objective was to evaluate the shaping ability of XP-endo Shaper and Mtwo systems in oval-shaped canals preparation by microcomputed tomography (micro-CT) along the entire canal. The volume, surface area and percentage of unprepared area were evaluated by image processing in entire canal and apical third (5 mm). Apical transportation and centring ability were evaluated at 3, 5 and 7 mm from the apex. Forty single-canal oval canines were paired in two groups (n = 20) according to the instrumentation system: XP-endo Shaper and Mtwo. The teeth were scanned by micro-CT before and after instrumentation, using a thermal vat at 37°C. The XP-endo Shaper system was more effective in the instrumentation of oval-shaped canals when compared to Mtwo system, resulting in greater volume increases and lower percentage of unprepared canals walls in apical region. Regarding apical transportation and centring ability, no statistical difference was observed.