Apex locators in endodontics: in-vivo comparison between different devices and radiographic method

The precise measurement of the working length (WL) is pivotal for the success of endodontic treatments. Incorrect WL determination can lead to improper reaming and filling of the canal, posing risks of periradicular pathologies onset or failure to heal pre-existing conditions. Presently, apex locators are commonly used for WL determination, available in a variety of characteristics and costs. Alternatively, the traditional method using intraoral radiography remains prevalent.

This study, conducted partly in vivo and partly in vitro, on teeth designated for extraction, compares three WL measurement methods: 1) radiographic method (zero cost); 2) Apex Locator (inexpensive); and 3) Root ZX II (expensive). The correctness of measurements was verified through visual inspection under a stereomicroscope.

Our data indicate that the precision of apex locators surpasses that of the radiographic method, which relies on visual inspection of the instrument inside the canal and is subject to personal interpretations of the images. No significant differences in precision were observed between the two locators examined, despite their differing price ranges and brand histories in the field of endodontics.

Among the multitude of parameters influencing a dentist's choice of electro-medical equipment, cost remains a significant consideration, particularly when equipment exhibits similar characteristics.