Comparative evaluation of the accuracy of two electronic apex locators in determining the working length in teeth with simulated apical root resorption: An in vitro study

Introduction: Accurate determination of working length (WL) is a critical factor for endodontic success. This is commonly achieved using an apex locator which is influenced by the presence or absence of the apical constriction. Hence, this study was done to compare the accuracy of two generations of apex locators in teeth with simulated apical root resorption. Materials and Methods: Forty maxillary central incisors were selected and after access preparation, were embedded in an alginate mold. On achieving partial set, teeth were removed, and a 45° oblique cut was made at the apex. The teeth were replanted and stabilized in the mold, and WL was determined using two generations of apex locators (Raypex 5 and Apex NRG XFR). Actual length of teeth (control) was determined by visual method. Statistical Analysis: Results were subjected to statistical analysis using the paired t-test. Results: Raypex 5 and Apex NRG was accurate for only 33.75% and 23.75% of samples, respectively. However, with ±0.5 mm acceptance limit, they showed an average accuracy of 56.2% and 57.5%, respectively. There was no significant difference in the accuracy between the two apex locators. Conclusion: Neither of the two apex locators were 100% accurate in determining the WL.