Scanning electron study of the combined enlarging effects of Hedstroem followed by Kerr file in sequence of sizes.
D003762:Dental Instruments; D005069:Evaluation Studies as Topic; D006801:Humans; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D012390:Root Canal Therapy / Q000295:instrumentation / Q000379:methods*