In vitro evaluation of the accuracy of Root ZX series electronic apex locators

Abstract

Background/Purpose To evaluate the accuracy of Root ZX series electronic apex locators (EALs) for locating the apical constriction. Materials and methods Forty-two extracted human teeth were mounted in the same experimental apparatus used for research on Root ZX series EALs. Each root canal was measured with all Root ZX series EALs (5 groups). In Groups 1 (Root ZX) and 2 (DentaPort ZX), the apex was located with an EAL only; in Groups 3 (Solfy ZX), 4 (TriAuto ZX) and 5 (DentaPort ZX), the apex was located with an EAL and handpiece in the passive mode. The actual canal length was visually measured by inserting a size 15 K-file until its tip could be observed at the major apical foramen under 16 times magnification, and the working length was determined by subtracting 0.5 mm from this length. The experiment was set up, and the devices were used to detect the apical constriction when the meter value reached the “0.5” mark on each EAL. Results The results demonstrated that the mean distance between the file and apical constriction was 0.10–0.19 mm more apically located than those indicated with the Root ZX series EALs. Furthermore, the accuracy of the Root ZX series EALs in determining the working length within ± 0.5 mm from the apical constriction varied from 90.48% to 97.62%. No significant difference was found among the experimental groups (P > 0.05). Conclusion The results of the present study confirm that Root ZX series EALs can accurately determine the apical constriction.