Effects of simulated lateral canals on the accuracy of measurements by an electronic apex locator.

BACKGROUND Accurate determination of the apical terminus plays a significant role in the success of root canal therapy, but accuracy may be affected by the presence of accessory canals. OBJECTIVE To evaluate the accuracy of a ratio-based electronic apex locator for roots with simulated lateral canals. METHODS Forty-two single-rooted human teeth were randomly divided into 2 groups. For each tooth, the root canal was prepared to the visually determined working length, and the working length was then measured with the Justy II electronic apex locator. Simulated lateral canals (of 2 different diameters) were then prepared at 3 mm (group A) or 6 mm (group B), and the working lengths were measured again with the same instrument. The measurements were analyzed by one-way analysis of variance. RESULTS For both groups, there were no significant changes in working length after the creation of simulated canals (p > 0.05). CONCLUSION Measurements obtained with the ratio-based electronic apex locator were not affected by the preparation of simulated lateral canals, and the instrument was able to accurately determine the location of the tooth apex.