Accuracy of Working Length Determination using NovApex and Root-ZX Apex Locators: An in vitro Study.

INTRODUCTION: This ex vivo study evaluated the accuracy of the Root-ZX electronic apex locator (EAL) (J. Morita, Tokyo, Japan) and the NovApex (Forum Technologies, Rishon Lezion, Israel) in determining the working length (WL) during endodontic treatment. MATERIALS AND METHODS: Forty extracted single-rooted human teeth were selected for this study. The actual WL was measured with visual technique by a size #15 k-file under magnification. Then, the canal lengths were measured electronically with both Root-ZX and NovApex apex locators within +/-0.5 and +/-1 mm. Mean percentage of data was analyzed between groups using paired t-test, with a statistically significant level of p < 0.05. RESULTS: The accuracy of NovApex apex locator was 85% within +/-0.5 mm and 92.5% within +/-1 mm. The accuracy of Root-ZX apex locator was 70% within +/-0.5 mm and 97.5% within +/-1 mm. There was no significant difference between the accuracy of the two EALs. CONCLUSION: Both the NovApex and Root-ZX EALs are useful for measuring the WL with high accuracy. CLINICAL SIGNIFICANCE: Given the importance of accurate WL determination in the success of endodontic treatments, the accuracy of different apex locators should be evaluated.