Accuracy and repeatability of 3 apex locators in locating root canal perforations: an ex vivo study.
INTRODUCTION
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.
["D'Assunção|Fábio Luiz Cunha|FL|", 'Sousa|Julio Cézar Nascimento|JC|', 'Felinto|Kayo César Amaro|KC|', 'de Medeiros|Thiago Clístines|TC|', 'Leite|Diego Tavares|DT|', 'de Lucena|Raissa Bezerra|RB|', 'de Oliveira Lima|Joab|J|']
D003188:Composite Resins D003786:Dental Pulp Cavity D055615:Electrical Equipment and Supplies D006801:Humans D007091:Image Processing, Computer-Assisted D008422:Materials Testing D009811:Odontometry D010781:Photography D016300:Radiography, Bitewing D015203:Reproducibility of Results D018915:Root Canal Preparation D019227:Tooth Apex
Apex locators Mini Apex Locator Root ZX II root perforation