An endodontic instrument adapted to be axially reciprocated within a root canal to remove material from walls of the root canal. The endodontic instrument includes an elongate shaft and a working portion. The elongate shaft includes a proximal end adjacent a handle and a distal end terminating at a tip spaced from the proximal end by the length of the instrument. The working portion includes a first helical fluted cutting surface for removing material from the walls of a root canal and a second helical fluted cutting surface for removing material from the walls of a root canal. The first helical fluted cutting surface and second helical fluted cutting surfaces are formed in opposing left-hand and right-hand directions such that material is removed form the walls of a root canal when the instrument is rotated in either a first or a second direction.