Patent ID: 7435086

Claim:
An elongated dental tool for use in cleaning and/or shaping a tooth root canal comprising: an elongated shank having a proximal end portion, a distal end and a tapered working portion of determined length extending from said proximal portion to said distal end; the external surface of said shank working portion being defined in part by three substantially identical equally spaced apart continuous concave helical flutes formed into a central core portion of said shank working portion, said flutes having therebetween three substantially identical spiraled spaced apart flanges, each flange having in a plane perpendicular to the length of a longitudinal axis of said shank, a substantially identical outer end each defined by a first and a second surface intersecting at a point of maximum radius from said axis providing three spaced apart continuous symmetrical scraping edges that, in use, have contact with a tooth root canal, each scraping edge extending from said shank proximal end portion to said shank distal end, said first surfaces being relatively short and said second surfaces relatively longer, said first and second surfaces having a same radius of curvature in said plane, said radius of curvature being greater than a radius of said shank working portion, said first and second surfaces providing substantially similar scraping characteristics irrespective of the direction of rotation of the dental tool in a root canal, and thereby eliminating any cutting edges irrespective of the direction of rotation of the tool.