Dg 16

For all the samples, uniform oval-shaped accesses were prepared using #245 bur (Mani Inc, Tochigi, Japan). The canal patency was checked using endodontic explorer, DG-16 (Dentsply Maillefer, Switzerland), and #10K file (Mani Inc, Kiyohara, Tochigi, Japan). The working length was confirmed radiographically. Cleaning and shaping of the root canals were performed with MTwo Ni-Ti rotary files up to size 35/.04 using X-smart (Dentsply Maillefer, Japan) torque control endodontic motor. After using each instrument, canals were irrigated using 2 ml of 3% sodium hypochlorite (Prime Dental Products Pvt Ltd., India). Root canals were then irrigated with 17% EDTA for 60 s to clear the smear layer. The final rinsing was carried out with 5 ml of sterile physiologic saline.

For all the test root samples, coronal access was prepared using #245 bur in a high-speed handpiece, and the canal patency was checked by inserting endodontic explorer DG-16 and #10 K-file (Dentsply Maillefer, Switzerland). The working length was determined and cleaning and shaping of the root canals were completed with ProTaper rotary Ni-Ti files (Dentsply Maillefer, Switzerland) upto F3 (#30/09) at a speed of 300 rpm using an Endo-Mate Endo Motor System (NSK NAKANISHI INC. Kanuma-Shi, Tochigi, Japan). The canals were irrigated with 2 ml of 3% NaOCl, after each instrumentation, using 27-gauge side vented needle and syringe.
To simulate immature roots with open apexes, #1–5 Peeso reamers were used. A #5 Peeso reamer was passed beyond the apex so that apices were enlarged to a diameter of 1.5 mm. Following cleaning and shaping, all the root canals were irrigated with 5 ml of normal saline. Before the obturation, the root canals in all the root samples were irrigated with 17% ethylenediamine tetraacetic acid (EDTA) (Canalarge, Ammdent, Mohali, India) for 1 min to remove the smear layer. A final flush was done with 5 ml of normal saline and excess moisture from the canals was removed with sterile absorbent points.