[Clinical verification of measuring accuracy of an electronic apex localizer]

Root canal length was determined with an electronic apex locator in 253 root canals and compared to the results obtained by radiographic length determination. After electronic measurement the tip of the instrument only in 56.6% was 0-1 mm from the roentgenographic apex. The electronic device gave better results after pulpectomies than in nonvital cases. Even worse results were obtained in revision cases.