Comparison of Accuracy of Two Electronic Apex Locators and Evaluation of Impact of Apical Patency on Accuracy: An In Vitro Study

Abstract

Objective(s): Aim of the study was to compare accuracy and to investigate the importance of apical patency of 2 apex locators - ROOT ZX MINI and PROPEX PIXI. 
Materials and Methods: Under a dental operating microscope with an X25 magnification, the actual working length was measured. A size #10K file was inserted into the root canal, progressed until it was visible at the apical foramen, and then removed. The working length was then calculated. Readings of the 2 apex locators are then compared with the actual microscopic working length. The apical foramen is then blocked, and files are then inserted to the working length that was previously determined. To calculate the measurement error, the variation in apex locators' values following obstruction is compared to their initial measurements prior to blockage.
Results: When Root ZX micro and Pixi apex locators' mean working lengths (measured in mm) were compared before and after apical blocking using a Student Paired t Test, the difference between the two was significantly greater after the apical block. After apical blocking, the estimated error distance between the two EALs' working lengths did not demonstrate a discernible difference. [P=0.72].

Conclusion(s): When compared to Propex pixi, Root ZX mini was statistically more accurate. The accuracy of apex locators is negatively impacted by apical foramen obstruction, which was more obvious in Root ZX than Propex pixi.