4Hoer D, Attin T. The accuracy of electronic working length determination [J].Int Endod J,2004,37(2):125-131.
5OGINNI A,UDOYE C I.Endodontic flare-ups:comparison of incidence between single and multiple visits procedures in patients attending a Nigerian teaching hospital[J].Odontostomatol Trop,2004,27(108):23-27.
6DUNLAP C A,REMEIKIS N A,BEGOLE E A,et al.An in vivo evaluation of an electronic apex locator that uses the ratio method in vital and necrotic canals[J].J Endod,1998,24(1):48-50.