The accuracy of the Root ZX electronic apex locator using stainless-steel and nickel-titanium files.

Numerous apex locator studies have been performed. Generally, they use only stainless-steel hand files for testing purposes. Today many clinicians use both stainless-steel and nickel-titanium files during the treatment of a case. Given the widespread use of nickel-titanium files, a comparison of the accuracy in determining length with an apex locator using stainless-steel and nickel-titanium files seems clinically relevant. Campbell et al. (1) published a study where only nickel-titanium files were used. A literature search failed to reveal any studies that directly compared stainlesssteel and nickel-titanium files when used with an apex locator to determine length measurements in the same tooth. The purpose of this study was to determine if there is a measurable difference in accuracy of length determination when stainless-steel and nickeltitanium files were used for this purpose in the same tooth.