Effect of Rotary File Number on MB2 Canal Negotiation and Postoperative Pain

A single-file NiTi system (25/.04) operated at 300 rpm and 2.5 Ncm torque. Applied directly to the MB2 canal without prior hand instrumentation.

Two-file system using 10/.06 Shaper for coronal/middle thirds and 25/.04 Finisher for apical third. Operated at 300 rpm and 2.0-2.5 Ncm torque.

Three-file NiTi rotary system (15/.04, 20/.05, 25/.04) used sequentially for coronal, middle, and apical thirds. Applied with brushing-pecking motion in 2-3 mm increments under continuous irrigation. Operated at 300 rpm and 1.8 Ncm torque.

NiTi rotary file system including 10/.07 Opener, 10/.04, 17/.05, and 25/.04 files. Used in crown-down sequence with rpm and torque settings ranging from 250-300 rpm and 2.0-2.5 Ncm. Brushing-pecking motion and continuous irrigation were applied during instrumentation.