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.