An improved endodontic instrument has a uniform tapered working length with at least two helical shaped flutes and spiraled lands having a land width no greater than 0.101 mm as measured in a plane perpendicular the central axis of rotation of instrument. The land width is preferably constant along the working length but may vary provided it does not exceed 0.101 mm. The instrument resists mid-root transportation and exhibits superior fatigue performance and cutting efficiency compared to prior art instruments.
