title: Comparative evaluation of the accuracy of two electronic apex locators in determining the working length in teeth with simulated apical root resorption: An in vitro study.
abstract: BACKGROUND
  Accurate determination of working length (WL) is a critical factor for endodontic success. This is commonly achieved using an apex locator which is influenced by the presence or absence of the apical constriction. Hence, this study was done to compare the accuracy of two generations of apex locators in teeth with simulated apical root resorption.
  
  
  METHODS
  Forty maxillary central incisors were selected and after access preparation, were embedded in an alginate mold. On achieving partial set, teeth were removed, and a 45° oblique cut was made at the apex. The teeth were replanted and stabilized in the mold, and WL was determined using two generations of apex locators (Raypex 5 and Apex NRG XFR). Actual length of teeth (control) was determined by visual method.
  
  
  METHODS
  Results were subjected to statistical analysis using the paired t-test.
  
  
  RESULTS
  Raypex 5 and Apex NRG was accurate for only 33.75% and 23.75% of samples, respectively. However, with ±0.5 mm acceptance limit, they showed an average accuracy of 56.2% and 57.5%, respectively. There was no significant difference in the accuracy between the two apex locators.
  
  
  CONCLUSIONS
  Neither of the two apex locators were 100% accurate in determining the WL.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Vidya
authors.initials: V
authors.lastname: Saraswathi
authors.affiliation: Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Archit
authors.initials: A
authors.lastname: Kedia
authors.affiliation: Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Tina Puthen
authors.initials: TP
authors.lastname: Purayil
authors.affiliation: Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Vasudev
authors.initials: V
authors.lastname: Ballal
authors.affiliation: Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal University, Manipal, Karnataka, India.
authors.forename: Aakriti
authors.initials: A
authors.lastname: Saini
keywords: Apex locator; apical resorption; working length