Precision of two different electronic apex locators for working length determination across various embedding media: an in vitro assessment.

Abstract

Introduction: Electronic apex locators (EALs) are essential for precise working length determination, but their accuracy can be influenced by the electrical properties of the surrounding tissues. Objectives: This study aimed to evaluate the E-PEX EAL's accuracy in comparison to Root ZX II in determining working length across three various embedding mediums. Materials and Methods: 42 extracted human teeth with a single root were decoronated, and actual lengths (AL) were established microscopically. Specimens were randomly assigned to alginate, agar, or bovine gelatin embedding media (n = 14 per medium). Canal lengths were measured using E-PEX and Root ZX II. Data were analyzed using a Mixed-Model ANOVA with Bonferroni correction. Results: Both EALs demonstrated high accuracy across all media, ranging from 85.7% to 100% of readings within ±0.5 mm of AL. There were no statistically significant differences between the devices in any medium after correction. In the bovine gelatin group, the E-PEX showed a trend toward greater deviation compared to Root ZX II (uncorrected p = 0.042); however, following controlling for multiple comparisons, this variation was not statistically significant (p > 0.05). Conclusions: Both the E-PEX and Root ZX II electronic apex locators provide high precision in determining working length, with most readings falling within ±0.5 mm of the actual length across all tested embedding media. Additionally, the E-PEX performs comparably to the recognized Root ZX II in simulated clinical conditions.