A comparative evaluation of the accuracy of third generation electronic apex locator (root zx) and conventional radiography to determine working length - An in vivo study

Abstract

Aim: The purpose of this in vivo study was to compare the accuracy of a third generation electronic apex locator (Root ZX) and conventional radiography in determining the working length. Method: Twenty adult human teeth indicated for extraction were taken for the study. Endodontic access was prepared, pulp extirpated, canals irrigated and the pulp space dried. Occlusal reference point was established. A third generation electronic apex locator, Root ZX was used according to the manufacture’s instructions to measure the working length. The working length was also measured by conventional radiography using Ingles method. After extraction, No. 15 K file with rubber stop was introduced into the canal and advanced until the file tip was visualized at the foramen using 3X magnification. The true canal length was measured for each tooth and the measurements were read to the nearest 0.5 mm. The actual working length was then established by subtracting 0.5 mm from the true canal length. Result: The mean of the working length determined was calculated. Mean of the working length obtained by Root ZX (G1) and that obtained by conventional radiographic method (G2) was compared with the mean of the actual working length (G3) by One sample T test. The results revealed no statistically significant difference between the actual working length and the working length obtained by Root ZX and conventional radiography. Even though Root ZX showed less deviation from the actual working length than the conventional radiographic method, there was no significant difference between the actual working length, the working length obtained by Root ZX and conventional radiography. Conclusion: Working length determined using Root ZX showed lesser deviation from actual working length compared to conventional radiographic method, even though there was no statistically significant difference between the experimental groups. Clinical significance: The third generation apex locators are reliable tool for the determination of the working length, even though the use of intra oral radiography cannot be ignored. A technique that combines the use of electronic devices and radiograph will certainly reduce the radiation exposure, since the adjustment of the lengths of the file would be minimal.