EVALUATION OF THE ACCURACY OF TWO APEX LOCATORS AND RADIOVISIOGRAPHY-AN IN VITRO STUDY

Abstract

Determination of an accurate working length is one of the most critical steps of Endodontic therapy. The cleaning, shaping and obturation of root canal system cannot be accomplished accurately unless working length is determined precisely. Locating the appropriate apical position always has been a challenge in clinical Endodontics. The cementodentinal junction (CDJ), where the pulp tissue changes into the apical tissue, is the most ideal physiologic apical limit of the working length. However, the CDJ and apical constricture do not always coincide, particularly in senile teeth as a result of cementum deposition, which alters the position of the minor diameter. In an attempt to measure the working length to a value that almost coincides with the actual length or anatomic length and to overcome all the errors that could occur due to the limitation of the present techniques used, electronic apex locators with their inherent capacity to minimize the errors and the simplicity of the technique involved in the calibration of working length seems to be an important break through in the field of Endodontics. 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.