title: A comparison between two fourth generation apex locators.
abstract: OBJECTIVE
  The aim of this study was to evaluate ex vivo the accuracy of two fourth generation apex locators and compare the measurements obtained.
  
  
  METHODS
  Forty single and multiroots of permanent teeth (i.e., sixty-two canals) without caries or restorations were selected. After determining the real canal length using a stereomicroscope and a digital calliper, we evaluated the accuracy of two fourth generation electronic apex locators (the Bingo 1020 and the Propex) by means of an experimental study model and an endodontic simulator. The experimental model uses a digital comparator to determine the root canal length to a precision of 0.001 mm, while the endodontic simulator replicates the normal clinical condition. The difference between the real length of each canal and that obtained with the two study models was calculated.
  
  
  RESULTS
  In both experiments, the Bingo 1020 expressed a 94.35% and the Propex expressed a mean accuracy of 90.31% in positioning the file at ± 0.5 mm.
  
  
  CONCLUSIONS
  The Bingo 1020 and the Propex apex locators are equally accurate and provide reliable measurements in calculating root canal length.
authors.affiliation: Section of Dentistry and Maxillo-Faccial Surgery, Surgery Department, University of Verona, Italy. l.comin-chiaramonti@libero.it
authors.forename: L
authors.initials: L
authors.lastname: Comin Chiaramonti
authors.forename: M
authors.initials: M
authors.lastname: Menini
authors.forename: G
authors.initials: G
authors.lastname: Cavalleri
mesh_terms: D003198:Computer Simulation; D003782:Dental Pulp / Q000648:ultrastructure; D003786:Dental Pulp Cavity / Q000648:ultrastructure; D004553:Electric Conductivity; D004582:Electronics, Medical / Q000295:instrumentation*; D006801:Humans; D066298:In Vitro Techniques; D003765:Models, Dental; D009811:Odontometry / Q000295:instrumentation* / Q000379:methods; D010513:Periodontal Ligament / Q000648:ultrastructure; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D019227:Tooth Apex / Q000648:ultrastructure*; D014092:Tooth Root / Q000648:ultrastructure