Instrument for drilling dental root canals

An instrument for drilling dental root canals comprising:

• a tapered rod defined by a single continuous taper function and having over at least an active part of its length a polygonal cross-section forming at least two cutting edges, said active part terminating by a point and being defined by an envelope of a cylindrical or conical shape along its entire length, the longitudinal axis of the envelope coinciding with the axis of rotation of the instrument,
• wherein for any cross-section of the active part, at least one of the at least two cutting edges is located on the envelope,
• said active part has a first portion extending from the point and a second portion extending following the first portion towards the rear of the active part,
• any cross-section of the first portion has a center of mass located on the axis of rotation, said at least two cutting edges defined by said cross-section of the first portion being located on the envelope,
• at least one cross-section of the second portion has a center of mass offset with respect to the axis of rotation, at least one cutting edge defined by said cross-section of the second portion being located set back within the envelope.