Effect of preflaring on Root ZX apex locators

The Root ZX apex locator is an example of a generation of apex locators tha t identify the terminus of the canal by measuring a ratio between two elect rical impedances. Studies have shown this device to have a high degree of a ccuracy. However, the manufacturer warns that the performance of these devi ces is limited by the presence of calcifications and dentinal shaving obstr uctions. An in vitro study was designed to determine if preflaring of canal s would facilitate the passage of files to the apical foramen by eliminatin g cervical interferences and to see what effect this would have on the perf ormance of the Root ZX apex locator. Thirty-two canals were divided into tw o groups. Group 1 was not manipulated before use of the Root Zx apex locato r and served as control. In group 2, the canals were preflared before the u se of the Root ZX apex locator. The working length files were secured in pl ace and measured with the linear measurement tool used by the Visilog 5 ima ging program. Results of this study suggest that preflaring of canals will allow working length files to more consistently reach the apical foramen (p = 0.015), which in turn increases the efficacy of the Root ZX apex locator .