title: Accuracy of four electronic apex locators: an in vitro evaluation.
abstract: In the present study, the accuracy and operator dependency of four electronic canal length measuring devices (Apex Finder AFA Model 7005, Apex-Finder, Neosono Ultima EZ and Apit 2) were compared under a set of specified conditions. The electronic apex locators were tested in unflared dry, flared wet and flared dry canals, and in a gelatin as well as in a sodium hypochlorite sponge model. Fifteen extracted single-canaled teeth were selected. The differences between canal lengths obtained by the electronic apex locators and actual canal lengths were scored. Only the Apex-Finder was found to be unreliable (measurements higher than +/- 0.5 mm from the apical foramen). This device was also found to be particularly dependent on operator. A ranking based on a precision of +/- 0.1 mm from the apical foramen showed the Apex Finder AFA Model 7005 to be the most accurate. Early coronal flaring did not ensure better or more precise readings. The gelatin model was evaluated to be more suitable for testing electronic apex locators in vitro than the sodium hypochlorite model.
authors.affiliation: Department of Operative Dentistry and Endodontology, School of Dentistry, University Hospital, University of Gent, Belgium.
authors.forename: R J
authors.initials: RJ
authors.lastname: De Moor
authors.forename: G M
authors.initials: GM
authors.lastname: Hommez
authors.forename: L C
authors.initials: LC
authors.lastname: Martens
authors.forename: J G
authors.initials: JG
authors.lastname: De Boever
mesh_terms: D000704:Analysis of Variance; D003762:Dental Instruments; D003786:Dental Pulp Cavity / Q000033:anatomy & histology; D005069:Evaluation Studies as Topic; D006801:Humans; D015588:Observer Variation; D009811:Odontometry; D015203:Reproducibility of Results; D018915:Root Canal Preparation / Q000295:instrumentation*; D019227:Tooth Apex; D014092:Tooth Root / Q000033:anatomy & histology