Conclusion
No individual technique is truly satisfactory in determining endodontic working length.
The CDJ is a practical and anatomic termination point for the preparation and obturation of the root canal and this cannot be determined radiographically.
Modern electronic apex locators can determine this position with accuracies of greater than 90% but still have some limitations.
Knowledge of apical anatomy, prudent use of radiographs and the correct use of an electronic apex locator will assist practitioners to achieve predictable results