Effect of Irrigation-Activation Techniques on Healing in Large Periapical Lesions

The root canals were filled with irrigation solutions. A main gutta percha cone was positioned 1 mm shorter than the working length and 2 mm coronal-apical direction movement was performed at a rate of 100 strokes per minute during 60 s.

A non-cutting ultrasonic tip (IRRI S 21/25; VDW, Munich, Germany) coupled to an ultrasonic device (DTE S6 Led, Guilin Woodpecker Co., Guilin, Guangxi, China) (mode: E, setting: 6) was used according to the manufacturer's recommendations.

A 2940 nm Er:YAG-laser device (Lightwalker, Fotona, Ljubljana, Slovenia), equipped with a handpiece (H14, Fotona) holding a 8.5 mm long and 600 µm diameter-tapered fiber tip (SWEEPS 600, Fotona) was used for irrigation activation. The device was set to AutoSWEEPS mode with two ultrashort micropulse durations (25 μs) continuously varying at 0.3 W, 20 mJ, 15 Hz settings. The air and water sprays were turned off.