Patent ID: 8882504

Claim:
An endodontic instrument for preparing an endodontic cavity space, the instrument comprising: a shank configured for attachment to a motor to rotate the endodontic instrument about an axis of rotation; and a body extending from the shank by a length, the body having a tip end and a shank end and a working surface between the shank end and the tip end, the working surface including multiple cutting edges, at least a portion of the body with the working surface being tapered such that the tip end has a diameter that is less than a diameter of the shank end, the body comprising a plurality of transverse cross-sections, each transverse cross-section of the body having a center of mass, the body having a center of mass path that is defined by the centers of mass of all transverse cross-sections of the body, wherein the center of mass path of the body rotates around the axis of rotation such that the working surface of the body swaggers when the instrument is rotated about the axis of rotation at a speed appropriate for preparing the endodontic cavity space, wherein the swagger results in, along an entire length of the working surface, one or more cutting edges of the multiple cutting edges being out of contact with a wall of the endodontic cavity space, wherein a number of sides of the plurality of transverse cross-sections is constant, and wherein the plurality of transverse cross-sections are defined by a polygonal shape that rotates about the axis of rotation from the shank end to the tip end.