Aim: The accuracy of three electronic apex locators (EALs) during retreatment of root-end resected teeth with different resection bevel angles were evaluated in the present study.
Materials and Methods: Forty mandibular premolar teeth were divided into two groups regarding resection bevel angle after root canal filling. In the first group, the apical 3 mm of each specimen was resected at a 0-degree bevel angle using a diamond bur. The resection bevel angle was approximately 45-degree in the second group. Electronic length measurements were obtained with a size 15 K-file advanced apically in dissolved gutta percha using Dentaport ZX, Propex Pixi, and Apit 15. The filling materials were then completely removed from the root canals, and the actual lengths up to the resection region were determined. The actual length was subtracted from the electronic length measurements for each specimen. Measurements were analyzed statistically using independent sample t-test, repeated-measures analysis of variance, and Bonferroni tests. The level of statistical significance was defined as P