Comparison of three different apex locators in determining the working length of mandibular first molar teeth with irreversible pulpitis compared with an intraoral periapical radiograph: A block randomized, controlled, clinical trial.

In the present study, we observed the negligible differences in readings between the EAL at the APEX mark readings, coinciding with the radiographic observation. Clinically, we recommend the apical foramen be located with the apex locators' APEX mark readings prior to identifying the apical constriction position.