title: An ex vivo comparison of working length determination by 3 electronic apex locators.
abstract: OBJECTIVE
  To compare the accuracy of 3 different electronic apex locators (EALs) in establishing the working length in recently extracted teeth.
  
  
  METHODS
  Sixty teeth (100 canals) were soaked in an alginate model and electronically measured with 3 EALs (Dentaport ZX, Raypex 5, and Elements Diagnostic Unit and Apex Locator). The real working length was calculated as 1.0 mm short of the real length of the canal. The electronic measurements were taken following the manufacturers' orientations within +/-0.05 mm and +/-1.0 mm using a #15 K-file attached to the holder, after canal irrigation with 1% NaOCl. Data were analyzed with Friedman test and Wilcoxon signed rank test, at a significance level of 5%.
  
  
  RESULTS
  Within +/-0.5 mm and +/-1.0 mm, the accuracy was 39% and 90% (Dentaport ZX), 31% and 82% (Raypex 5), and 37% and 73% (Elements Diagnostic Unit and Apex Locator), respectively, with statistically significant differences between Elements Diagnostic Unit and Apex Locator and the other EALs.
  
  
  CONCLUSIONS
  None of the EALs yielded an accuracy of 100%. Within the limitations of the present study. Elements Diagnostic Unit and Apex Locator proved to be less reliable than Dentaport ZX and Raypex 5 in the determination of the real working length.
authors.affiliation: Calabrodental Centro Odontoiatrico, Crotone, Italy.
authors.forename: Elizeu Alvaro
authors.initials: EA
authors.lastname: Pascon
authors.forename: Massimo
authors.initials: M
authors.lastname: Marrelli
authors.forename: Orsola
authors.initials: O
authors.lastname: Congi
authors.forename: Rosetta
authors.initials: R
authors.lastname: Ciancio
authors.forename: Federica
authors.initials: F
authors.lastname: Miceli
authors.forename: Marco Aurélio
authors.initials: MA
authors.lastname: Versiani
mesh_terms: D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D004582:Electronics, Medical / Q000295:instrumentation* / Q000706:statistics & numerical data; D006801:Humans; D008422:Materials Testing; D009811:Odontometry / Q000295:instrumentation* / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D012388:Root Canal Irrigants / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D019227:Tooth Apex / Q000033:anatomy & histology*
chemical_list: D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite