A comparative evaluation of working length with digital radiography and third generation apex locator (ProPex) in the presence of various intracanal irrigants: An in vivo/ex vivo study

Abstract

Background: Accurate working length determination is a pre-requisite for a successful endodontic

treatment. Even with improved systems of working length measurement, different readings may be

recorded in different electrolytes present in the canal. The purpose of this in vivo/ex vivo comparative

study was to determine the accuracy in measuring the working length of root canal using Direct

Digital Radiographic Method (Radiovisiography or RVG) and ProPex electronic apex locator in the

presence of three different irrigating solutions: 0.9% normal saline, 2% chlorhexidine, 3% NaOCl

solutions.

Materials and Methods: Forty single-rooted human teeth scheduled for extraction with mature

apices were selected for this study. Measurements were performed by using RVG and ProPex in the

presence of irrigating solutions. After extraction of the teeth, light microscope was used to confi rm

visually the relationship of the tip of the endodontic fi le to the apical foramen, and actual lengths

were determined by reducing 0.5 mm from this length. The statistical analysis was performed by

one-way ANOVA test and Tukey-HSD post hoc procedure. P < 0.05 was considered as signifi cant.

Results: No signifi cant difference was found between overall mean electronic working length

and digital radiographic length; however, prediction error (P < 0.05) was signifi cant with respect

to different irrigants. Among the irrigating solutions, chlorhexidine gluconate had the smallest

distance to the actual lengths, whereas NaOCl had the greatest.

Conclusion: Electronic apex locator ProPex yielded best result in the presence of chlorhexidine,

whereas the largest error was demonstrated with NaOCl indicating that higher electroconductive

irrigating solutions affect the precision of multi-frequency apex locators.

Key Words: Apex locators, digital radiography, irrigation solutions, working length