title: Accuracy of an Electronic Apex Locator for Working Length Determination in Primary Anterior Teeth.
abstract: OBJECTIVE
  Correct determination of working length is an important step for success of endodontic therapy. Conventional radiography has limitations in providing the accurate location of apical foramen. For this reason, electronic apex locators (EALs) were developed to shorten the treatment time and decrease the radiation dose. The aim of this study was to evaluate the accuracy of Root ZX EAL for working length determination in primary anterior teeth.
  
  
  METHODS
  In this in-vitro study, 50 extracted primary anterior teeth with root resorption were selected with no obstructed canals or history of previous root canal therapy. Working lengths were measured by direct observation of actual length (AL), radiography and Root ZX EAL. A variation of ±0.5 mm from the AL was considered acceptable. The results were analyzed statistically using paired t-test and interclass correlation coefficient (ICC) at 0.05 level of significance.
  
  
  RESULTS
  Considering an acceptable 0.5 mm margin from AL (direct measurement), the accuracy of Root ZX EAL and radiography was found to be 86% and 76%, respectively. Absolute value of error from AL was significantly lower for ZX compared to radiography (P<0.001). Interclass correlation comparing both radiography and Root ZX with AL showed strong correlations.
  
  
  CONCLUSIONS
  Root ZX EAL can be used as a reliable tool for obtaining root canal length in primary anterior teeth with resorption.
authors.affiliation: Associate Professor, Department of Pediatric Dentistry, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Bahrololoomi
authors.affiliation: Assistant Professor, Department of Pediatric Dentistry, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Ali Asghar
authors.initials: AA
authors.lastname: Soleymani
authors.affiliation: Assistant Professor, Department of Endodontics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Jalil
authors.initials: J
authors.lastname: Modaresi
authors.affiliation: Dentist, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors.forename: Mahsa
authors.initials: M
authors.lastname: Imanian
authors.affiliation: Assistant Professor, Department of Pediatric Dentistry, Faculty of Dentistry, Qazvin University of Medical Sciences, Qazvin, Iran.
authors.forename: Malihe
authors.initials: M
authors.lastname: Lotfian
keywords: Radiography; Tooth Apex; Tooth, Deciduous