Accuracy of Working Length Determination - Electronic Apex Locator Versus Cone Beam Computed Tomography

Objective: To compare the accuracy of working length determination between cone beam computed
tomography (CBCT) and electronic apex locator by measuring the actual working length of teeth. Material
and Methods: A total of 150 single-rooted tooth assessed by radiograph undergoing root canal therapy were
selected. The process was repeated to obtain a buccolingual and mesiodistal section of all teeth. The
measurement line was considered from the reference occlusal plane following the center of the canal to the
terminus. All information regarding the accuracy of cone-beam computed tomography and apex locator was
noted in a pre-designed proforma. Results: CBCT consistently demonstrated high accuracy across all tooth
types in both jaws. The electronic apex locator exhibited varying precision, with greater accuracy observed
in the mandible. Statistical analyses revealed significant differences in electronic apex locator accuracy among
tooth types in the maxilla (p=0.042), emphasizing the importance of specific clinical considerations.
Conclusion: Cone beam computed tomography emerges as a reliable diagnostic tool for accurate working
length determination, especially in complex cases, while the electronic apex locator remains valuable with
careful consideration of potential variations in accuracy. An individualized approach, considering tooth type,
jaw location, and clinical context, is crucial for precise working length determination in endodontic practice.