title: Accuracy and repeatability of 3 apex locators in locating root canal perforations: an ex vivo study.
abstract: BACKGROUND
  This study was an ex vivo evaluation of the accuracy and repeatability of 3 electronic apex locators (EALs) in locating simulated root canal perforations.
  
  
  METHODS
  Thirty-five human teeth were used. Perforations were placed 5 mm from the apex of each specimen. A #15 K-file was attached to a micrometer, and the specimens were fixed in a mounting model. The EALs were connected to the files, and electronic measurements of the simulated perforations were obtained. This procedure was repeated, the files were cemented in place, and x-rays were obtained to evaluate the distances between the measurement files and the simulated perforations. The obtained results were compared with the corresponding control lengths. Three investigators evaluated the distance of the file position in relation to the perforation for each specimen. The 3 investigators reached consensus regarding these measurements.
  
  
  RESULTS
  Statistical analyses of the results revealed that the EAL reliabilities in the exact detections of the root canal perforations were 97.1% for the Mini Apex Locator, 100% for the Root SW, and 91.4% for the Root ZX II. Analysis of variance revealed that the accuracies of the 3 devices were not different (P > .05). The results also indicated high levels of repeatability for each of the 3 EALs (intraclass correlation coefficients: 0998, 0.999, and 0.999 for the Mini Apex Locator, Root SW, and Root ZX II, respectively).
  
  
  CONCLUSIONS
  It was concluded that each of these 3 EALs provided excellent ex vivo accuracy in locating root perforations and that all tested devices possess excellent ex vivo repeatability.
authors: Department of Endodontics Restorative Dentistry, Federal University of Paraiba, Paraiba, Brazil. Electronic address: fabioendodontia@gmail.com.
authors: Fábio Luiz Cunha
authors: FL
authors: D'Assunção
authors: Department of Endodontics, University Center of João Pessoa, Paraiba, Brazil.
authors: Julio Cézar Nascimento
authors: JC
authors: Sousa
authors: Department of Endodontics Restorative Dentistry, Federal University of Paraiba, Paraiba, Brazil.
authors: Kayo César Amaro
authors: KC
authors: Felinto
authors: Odontologic Center of Studies and Research, João Pessoa, Paraiba, Brazil.
authors: Thiago Clístines
authors: TC
authors: de Medeiros
authors: Department of Endodontics Restorative Dentistry, Federal University of Paraiba, Paraiba, Brazil.
authors: Diego Tavares
authors: DT
authors: Leite
authors: Department of Endodontics, University Center of João Pessoa, Paraiba, Brazil.
authors: Raissa Bezerra
authors: RB
authors: de Lucena
authors: Department Statistics, Federal University of Paraiba, Paraiba, Brazil.
authors: Joab
authors: J
authors: de Oliveira Lima
mesh_terms: D003188:Composite Resins / Q000737:chemistry; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging / Q000293:injuries*; D055615:Electrical Equipment and Supplies / Q000706:statistics & numerical data*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008422:Materials Testing; D009811:Odontometry / Q000295:instrumentation* / Q000706:statistics & numerical data; D010781:Photography / Q000379:methods; D016300:Radiography, Bitewing / Q000379:methods; D015203:Reproducibility of Results; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000706:statistics & numerical data; D019227:Tooth Apex / Q000033:anatomy & histology* / Q000000981:diagnostic imaging
chemical_list: D003188:Composite Resins; C479082:natural flow composite resin
keywords: Apex locators; Mini Apex Locator; Root ZX II; root perforation