title: Accuracy of three electronic apex locators in anterior and posterior teeth: an ex vivo study.
abstract: BACKGROUND
  The aim of this study was to determine in anterior teeth, bicuspids, and molars (1) the accuracy of 3 different electronic apex locators (EALs) in detecting the apical foramen and (2) the accuracy of digital radiography in determining the working length (WL), compared with visible control under a microscope.
  
  
  METHODS
  By using radiovideography (RVG), we measured the lengths of 120 root canals with 3 different EALs (Endex, ProPex II, and Root ZX) and compared them with the actual lengths. The accuracy of EALs and RVG was related to each dental category. An endodontic training kit (Pro-Train) was used during experimental procedures.
  
  
  RESULTS
  Statistical analysis showed that the 3 EALs and RVG were less accurate in anterior teeth and molars than in bicuspids. The paired-sample t test showed no statistically significant difference between mesiodistal plane and buccolingual plane digital radiography in all groups.
  
  
  CONCLUSIONS
  The 3 EALs tested were more accurate in detecting the apical foramen in bicuspids than in both molars and anterior teeth. Radiographic measurements were not reliable for determining WL in all dental groups in both radiographic planes.
authors.affiliation: Department of Restorative Dentistry and Endodontics, University of Rome Tor Vergata, Rome, Italy. manuele.mancini@tiscali.it
authors.forename: Manuele
authors.initials: M
authors.lastname: Mancini
authors.forename: Roberto
authors.initials: R
authors.lastname: Felici
authors.forename: Gabriele
authors.initials: G
authors.lastname: Conte
authors.forename: Marco
authors.initials: M
authors.lastname: Costantini
authors.forename: Luigi
authors.initials: L
authors.lastname: Cianconi
mesh_terms: D000328:Adult; D001641:Bicuspid / Q000033:anatomy & histology; D002933:Cineradiography; D003481:Cuspid / Q000033:anatomy & histology; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055615:Electrical Equipment and Supplies / Q000706:statistics & numerical data; D004867:Equipment Design; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology; D008853:Microscopy / Q000706:statistics & numerical data; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology; D009811:Odontometry / Q000295:instrumentation* / Q000706:statistics & numerical data; D019252:Radiography, Dental, Digital / Q000706:statistics & numerical data; D018915:Root Canal Preparation / Q000295:instrumentation; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014092:Tooth Root / Q000033:anatomy & histology