Navitip sideport

In this group, the root canals were prepared with ProTaper Universal instruments used at 300 rpm with 2 Ncm torque (X-Smart, Dentsply Maillefer). An SX file was used at 1/2 of the WL; S1 and S2 files were at 2/3 of the WL; and F1, F2, F3, and F4 files were at full WL. SX, S1, and S2 files were used in the canals with a brushing motion, and the others were used with a gently in- and out-motion until the instrument had reached into the full WL. The root canals were irrigated with 1 mL distilled water after each instrument using a 31-gauge double side-port needle (NaviTip Sideport; Ultradent, USA). After instrumentation 1 mL, distilled water was used as a final rinse. A volume of 8 mL distilled water was used for irrigation.

A glide path was confirmed using K-files to allow for insertion of a size 20 K-file into the WL. The coronal third of the root canals were prepared using a size 3 Gates-Glidden bur (Kendo Munich, Germany), with 1.5 mm of diameter and 21 mm of a SAF file used at 5000 movements/min with an amplitude of 0.4 mm. Distilled water was continuously provided by a VATEA peristaltic pump (ReDent Nova Inc., Ra’anana, Israel) at a rate of 2 mL/min. The SAF file was used for 4 min, and hence a total of 8 mL distilled water was used for irrigation.
All root canal preparations were completed by one operator according to the manufacturers’ suggestions. Instruments were used only for preparation of three canals, with the exception of SAF and WaveOne files (single use). In each sample, a total of 8 mL distilled water was used as an irrigating solution with an automated irrigation system (SAF) or with a 31-gauge double side-port needle (NaviTip Sideport; Ultradent, USA) between files in the ProTaper Universal and Next groups and between pecking sequences in the WaveOne group. Apical patency was maintained by passing a size 15 file to WL after the use of each file.