Evaluation of The Effect of 980nm Diode Laser Intracanal Irradiation on Levels of Interleukin-8 Expression

After endodontic retreatment, root canals will be irradiated with a 980 nm diode laser coupled with optical fibre 200 μm (Litemedics, Italy) with setting 1.2-watt power, in pulsed mode. The irradiation protocol will be of 5-sec irradiation followed by a 10-sec pause, which constituted one lasing cycle. The lasing cycle will be performed four times for each tooth. The tip will be positioned 1 mm short of the apex. Followed by activation during which it will be slowly dragged at a speed of approximately 2 mm/ sec in a way that the root canals will be irradiated from the apical to the coronal portion, in a helicoidal movement touching the canal walls.

"After endodontic retreatment, mock laser application (Placebo group) will be applied:~The fiberoptic tip will be inserted inside the root canal, mimicking the laser irradiation group, but not activated"