Comparative evaluation of the accuracy of six different apex locators in working length determination of molars using intraoral periapical radiographs: An in vivo study

One of the crucial steps in endodontic treatment is determining the working length (WL). There are various methods for performing this procedure, one of which is an electronic apex locator (EAL) measurement. The aim of this study was to determine the accuracy of six EALs, i.e.. Root ZX, Root ZX Mini, Propex PiXi, Innvopex-1, Woodpex III, and Raypex 6 for WL estimation in the mandibular first molars. The study included 180 root canals with symptomatic irreversible pulpitis, divided into six groups using different apex locators. WL determination was compared with intraoral periapical radiographs. Results were categorized as accurate, short, or long. The data were statistically analyzed. ROOT ZX had an accuracy of 96.7%, Root ZX Mini had an accuracy of 93.3%, PiXi had an accuracy of 90.0%, Innvopex-1 had an accuracy of 90.0%, Woodpex III had an accuracy of 86.7%, and Raypex 6 had an accuracy of 83.4%, respectively. There was a statistically nonsignificant difference between groups (P < 0.05). Newly developed apex locators, such as the Innvopex-1, have shown accuracy comparable to well-established EALs like the Root ZX. This highlights the importance of conducting more extensive, large-scale research to confirm and validate their effectiveness.