This randomized controlled clinical trial aimed to evaluate the effect of different integrated electronic apex locator (EAL) modes on postoperative pain following nonsurgical endodontic retreatment. A total of 144 patients requiring retreatment of mandibular premolar teeth with periapical lesions were randomly assigned to four groups.
In the control group, working length was determined using a conventional electronic apex locator. In the experimental groups, an integrated EAL motor was used with three different modes: apical reverse, apical slow down, and apical stop.
All procedures were performed under standardized conditions. Postoperative pain was assessed using a numeric rating scale (NRS) at 6 and 12 hours and on days 1, 2, 3, 5, and 7 after treatment.
The study aimed to determine whether simultaneous working length control using integrated EAL modes influences postoperative pain compared with conventional working length determination.