title: Accuracy of working length determination using 3 electronic apex locators and direct digital radiography.
abstract: OBJECTIVE
  The objectives of this study were to assess the accuracy of working length determination using 3 electronic apex locators and direct digital radiography and to compare the results with those obtained using the visual method (control measurement).
  
  
  METHODS
  Twenty extracted human maxillary premolars were selected: 17 two-rooted and 3 single-rooted (total of 37 canals). Working length was measured using electronic apex locators Elements Diagnostic, Root ZX, and Just II. Subsequently, teeth were positioned in the alveolar bone of a dry skull and submitted to direct digital radiography. A variation of ±1 mm was considered as acceptable. Results were analyzed using the Wilcoxon and the χ(2) tests.
  
  
  RESULTS
  Results presented an accuracy of 94.6% for Elements Diagnostic, 91.9% for Root ZX, 73.0% for Just II, and 64.9% for direct digital radiography when considering the margin of ±1 mm in relation to the control measurement. Comparisons with the actual control measurements resulted in accuracy results of 13.51%, 13.51%, 10.10%, and 2.70%, respectively.
  
  
  CONCLUSIONS
  Root ZX and Elements Diagnostic are more accurate in determining working length when compared with Just II and Schick direct digital radiography.
authors.affiliation: School of Dentistry, Universidade Paulista (UNIP), São Paulo, SP, Brazil.
authors.forename: Denis Gonçalves
authors.initials: DG
authors.lastname: Real
authors.forename: Harry
authors.initials: H
authors.lastname: Davidowicz
authors.forename: Cacio
authors.initials: C
authors.lastname: Moura-Netto
authors.forename: Clacir de Lourdes Londero
authors.initials: Cde L
authors.lastname: Zenkner
authors.forename: Claudia Medianeira Londero
authors.initials: CM
authors.lastname: Pagliarin
authors.forename: Fernando Branco
authors.initials: FB
authors.lastname: Barletta
authors.forename: Abilio Albuquerque Maranhão
authors.initials: AA
authors.lastname: de Moura
mesh_terms: D001641:Bicuspid / Q000033:anatomy & histology; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D004581:Electronics / Q000295:instrumentation; D004867:Equipment Design; D006801:Humans; 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*