A comparative clinical study on the correlation of working length determined using three different electronic apex locators with radiographic working length: An in vivo study

Aim: This in vivo study was done to correlate the values of three different electronic apex locators: Root ZX, iPex, and Apex ID, with the radiographic working length (WL). Materials and Methods: Nineteen maxillary incisors with completely formed root apices indicated for endodontic treatment were chosen. After access preparation, coronal flaring and pulp extirpation, electronic measurement of WL was done with a No: 15 K file using the three devices on each tooth. A WL radiograph was then taken with the file placed within the canal and the length determined by following Ingle's method. The data were then analyzed using the correlation coefficient and Z -test. Results: Root ZX showed the maximum correlation ( r = 0.9881) with radiographic WL followed by Apex ID ( R = 0.9731) and iPex ( R = 0.9508). Root ZX had a statistically significant higher correlation with radiographic WL in comparison with iPex ( P Conclusion: Maximum correlation of readings with the radiographic length was shown by Root ZX followed by Apex ID and then by iPex.