Patent ID: 8047842

Claim:
An endodontic file for cleaning and shaping a tooth root canal comprising: an elongated tapered metal file having a proximal end, a distal end, a handle portion, and “n” spaced apart helical flutes with spiraled lands therebetween, a helix angle of said flutes increasing from said proximal end to said distal end; each of said lands having an edge that has a more positive cutting angle when the file is rotated in one direction and a scraping angle when the file is rotated in an opposite direction; said handle portion being configured for rotation in a handpiece, said handpiece selected from the group consisting of a manual handpiece and a rotary handpiece; said file being configured for sequential forwardly rotation followed by rearwardly rotation, thereby requiring rotation only slightly more than 360°/n forwardly then rearwardly to clean and shape a tooth root canal; a cross-sectional area of said flutes is concave polygonal-shaped at said proximal end and square-shaped at said distal end.