title: Accuracy of the iPex multi-frequency electronic apex locator in primary molars: an ex vivo study.
abstract: OBJECTIVE
  To evaluate ex vivo the accuracy of the iPex multi-frequency electronic apex locator (NSK Ltd, Tokyo, Japan) for working length determination in primary molar teeth.
  
  
  METHODS
  One calibrated examiner determined the working length in 20 primary molar teeth (total of 33 root canals). Working length was measured both visually, with the placement of a K-file 1 mm short of the apical foramen or the most coronal limit of root resorption, and electronically using the electronic apex locator iPex, according to the manufacturers' instructions. Data were analysed statistically using the intraclass correlation (ICC) test.
  
  
  RESULTS
  Comparison of the actual and the electronic measurements revealed high correlation (ICC = 0.99) between the methods, regardless of the presence or absence of physiological root resorption.
  
  
  CONCLUSIONS
  In this laboratory study, the iPex accurately identified the apical foramen or the apical opening location for working length measurement in primary molar teeth.
authors.affiliation: Department of Paediatric, Preventive and Community Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. nelson@forp.usp.br
authors.forename: P
authors.initials: P
authors.lastname: Nelson-Filho
authors.forename: P C
authors.initials: PC
authors.lastname: Romualdo
authors.forename: K C
authors.initials: KC
authors.lastname: Bonifácio
authors.forename: M R
authors.initials: MR
authors.lastname: Leonardo
authors.forename: R A B
authors.initials: RA
authors.lastname: Silva
authors.forename: L A B
authors.initials: LA
authors.lastname: Silva
mesh_terms: D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D055615:Electrical Equipment and Supplies; D006801:Humans; D008963:Molar / Q000033:anatomy & histology*; D009811:Odontometry / Q000295:instrumentation*; D019227:Tooth Apex / Q000033:anatomy & histology*; D014094:Tooth, Deciduous / Q000033:anatomy & histology*