Agreement of wired and wireless electronic apex locator measurements with CBCT-derived measurements in teeth with large periapical lesions and intracanal exudation: a prospective comparative clinical study

Working length determination may be challenging in teeth with large periapical lesions and intracanal exudation, conditions that may influence the performance of electronic apex locators (EALs). This study evaluated the repeatability of working length measurements obtained with two wired EALs (Propex Pixi and iPex II) and two wireless EALs (AirPex and the Bluetooth-enabled Wirele-X), as well as their agreement with cone-beam computed tomography (CBCT)-derived measurements under these clinical conditions.This study evaluated the repeatability of working length measurements obtained with three wired EALs (Propex Pixi, iPex II, and AirPex) and one Bluetooth-enabled wireless EAL (Wirele-X), as well as their agreement with cone-beam computed tomography (CBCT)-derived measurements under these clinical conditions. Seventy-one single-rooted, single-canal teeth from 42 patients with large periapical lesions and intracanal exudation were included. Working length was determined using four EALs: Propex Pixi, iPex II, AirPex, and Wirele-X. Three consecutive measurements were obtained with each device. CBCT measurements were performed twice, 7 days apart, by a blinded oral and maxillofacial radiologist. Repeatability was assessed using intraclass correlation coefficients (ICCs), and agreement with CBCT-derived measurements was evaluated using Bland–Altman analysis. Absolute deviations among devices were compared, and the proportions of measurements within ± 0.5 mm and ± 1.0 mm of the CBCT-derived measurements were assessed using Cochran’s Q test. All EALs demonstrated excellent repeatability (ICC ≥ 0.999). Although small statistically significant differences were observed among repeated measurements for AirPex and Wirele-X, their magnitude was clinically negligible. Absolute deviations from CBCT-derived measurements did not differ significantly among the four devices ( p = 0.554). Bland–Altman limits of agreement were approximately − 2.7 to + 2.6 mm. The proportions of measurements within ± 0.5 mm were 59.15% for Propex Pixi, 60.56% for iPex II, 61.97% for AirPex, and 61.97% for Wirele-X ( p = 0.927). Within ± 1.0 mm, the corresponding rates were 91.55%, 91.55%, 92.96%, and 90.14%, respectively ( p = 0.820). All four EALs demonstrated high measurement repeatability, with no statistically significant differences in their agreement with CBCT-derived working length measurements. However, the relatively wide Bland–Altman limits of agreement indicate that substantial discrepancies may occur in individual teeth despite the high repeatability of the devices.