DETERMINATION OF LOCATION OF ROOT PERFORATIONS BY ELECTRONIC APEX LOCATORS

Objectives. This study was conducted to evaluate the accuracy of two e lectronic apex. locators, the Sono Explorer Mark 2 Junior (Hakusui, Os aka, Japan) and Apit 2 (Osada, Tokyo, Japan) in detecting root perfora tions. The adequacy of radiographs for identifying root perforations w as also assessed. Study design. Thirty-two extracted human teeth were perforated in the middle third of the root and embedded in alginate. D etermination of all perforations were carried out with K-files no. 25 attached to the apex locators tested. Two radiographs were taken at tw o angulations after each electronic measurement. The actual location o f the file tip in relation to the perforation was determined with a st ereomicroscope. A total of 512 radiographs were evaluated to attempt t o identify root perforations. Results: The mean distance of the file t ip from the external outline of the root surface was short for both in struments. A statistical difference (p < 0.05) was found between the t wo apex locators in dry canals or if saline solution was present. Ther e was no significant difference between the two instruments in the pre sence of sodium hypochlorite. Evaluators radiographically identified 4 5% of the root perforations when located in buccal-lingual directions. Conclusion. Under the in vitro conditions of this study, both devices determined the location of the perforations in an acceptable clinical range short of the root surface. Radiographs were found to be less re liable in identification of perforation locations.