X smart plus motor

Fourteen single rooted and six multi rooted tooth samples were included in this group. Root canals were prepared by using the ProTaper Gold (PTG; Dentsply Maillefer, Ballaigues, Switzerland) operated in continuous rotation motion at 300 rpm and a torque of 5.2 Ncm by an electric motor (X-Smart Plus motor, Dentsply Maillefer). Hand instrumentation was done till size of 25 K -type hand file. The root canal preparation was done in presence of NaOCl “Floating” with files ranging from SX to S2. The final root canal preparation was done using finishing file F3(ISO diameter 30) with a brushing action according to canal anatomy.

The coronal 2 mm of obturating materials were removed using a size 3 Gates Glidden drill (Dentsply Sirona, Ballaigues, Switzerland). Then, 1–2 drops of chloroform were used to soften the obturating material to facilitate file penetration. WOG Primary file (size 25, 0.07) was operated with reciprocating motion using the “WAVEONE ALL” mode in the X-Smart Plus motor (Dentsply Sirona) to remove the obturating materials. Attempts were made to reach the working length. Then, 10 vertical brushing movements with 3 mm amplitude were performed. Afterward, the canal was dried with paper points and checked for remnants of gutta-percha under the microscope at 8 × magnification. When gutta-percha was found on the canal walls, another 10 vertical strokes were performed. The canals were irrigated using a 27G side-vented irrigating needle with a total of 9 ml volume (5 ml of 2.5% NaOCl throughout the procedure and a final rinse of 2 ml of 17% EDTA was performed before flushing with 2 ml of 0.9% sodium chloride). The total amount of time needed for retreatment by the use of the WOG Primary file inside the canal, including the additional strokes, where applicable, and irrigation was calculated. Regaining the apical patency was inspected using a size 15 K-file.
To mimic the clinical conditions, the procedure was conducted while the sample was surrounded with warm water at 35 ± 1 °C.