The Evaluation of Three Electronic Apex Locators in Teeth with Simulated Horizontal Oblique Root Fractures

Aim: The accuracy of three electronic apex locators (EALs) to locate the apical limit in teeth with simulated horizontal oblique root fractures was investigated. Material and methods: A horizontal oblique incomplete root fracture was simulated on 30 freshly extracted maxillary anterior teeth by means of a notch made on the vestibular root plane 8 mm from the anatomic apex. The EALs investigated were the ProPex II (Dentsply Maillefer, Ballaigues, Switzerland), the Mini Apex Locator (Sybron Endo, Orange CA), and the Dentaport ZX (J. Morita Corp, Kyoto, Japan). The electronic measurements were compared with the real “working length.” Results: The accuracy obtained was Dentaport ZX in 66.66% (n=20), the Mini Apex Locator in 63.33% (n=4) and the Propex II in 53.34% (n=4). The analysis of variance and chi-square test showed no statistical significant differences between Propex and Dentaport ZX EALs (Elecronic Apex Locators) at 0.5 mm and 1.0 mm tolerance levels. These results suggest that electronic apex locators can effectively and reproducibly detect oblique root fractures. Conclusion: Although Propex II apex locator was not able to determine the working length accurately, but Dentaport ZX and Mini Apex Locator were able to determine the working length within acceptable range.