| 摘要 |
The invention relates to an endodontic instrument (10) for drilling root canals, in particular a flexible drilling instrument, comprising a working part (11) and a securing end fitting (12) intended for mounting the instrument in a mandrel of a contra-angle-type support provided with an electric motor used to drive same clockwise. The casing of the working part (11) is conical along the length thereof and ends in a tip (13). The working part (11) is provided with a spiral flute (14) forming a ridge (20) having a cutting edge (24). The drill bit, relief and cutting angles defined by the cutting edge (24) can be varied along the length of the working part (11) so that the instrument is particularly sharp in the area near the tip (13) and so that the profile of the cutting ridge (24) becomes progressively more blunt along the length of the instrument (10). |
