Patent ID: 7270541

Claim:
A rotatable endodontic file for cleaning/shaping a tooth root canal, comprising: an elongated shaft having a proximal end portion, a distal end and a tapered working portion having a rotational axis, the working portion extending from said proximal portion to said distal end; the external surface of said shaft working portion having a plurality of at least two spiraled, equally spaced apart continuous concaved helical flutes, the flutes having therebetween an equal number of spiraled, spaced apart flanges, each flange having in a plane perpendicular said rotational axis an outer end surface forming a continuous spiraled scraping/cutting edge extending the length of said shaft working portion, said flutes each having a helical angle as measured relative to said shaft rotational axis at each location along the length of said shaft working portion and wherein there are at least two different helical angles for each said flute and wherein the helical angles are proportionally unrelated to locations or diameters along the length of said working portion.