This study evaluates the accuracy and repeatability of the Root ZX3 electronic apex locator for determining root canal working length in single-rooted permanent teeth requiring extraction. Before extraction, working length is measured clinically using the Root ZX3. Following extraction, cone-beam computed tomography (CBCT) measurements and microscopic actual working length are obtained, with the microscopic measurement serving as the reference standard. The study compares the diagnostic accuracy and agreement of the Root ZX3 with these reference measurements across different pulpal and periapical conditions.