| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve a method for manufacture of an endodontic instrument 10 such as a file or a reamer having a helical flute 24 or a non-helical flute 26 from a superelastic material. <P>SOLUTION: In the method for forming the endodontic instrument 10 having the helical flute, an instrument blank 23 of the superelastic material is brought to a particular annealed state before twisting, it is twisted at a low temperature to a final configuration, and then it is heat-treated and rapidly quenched to a superelastic condition. In a method for manufacture of the endodontic instrument having the helical flute or non-helical flute having a hard surface and a resilient cutting edge, a desired flute pattern is formed on the instrument blank by using an EDM or ECM process. A portion of a material removed from the surface re-deposits onto the surface being machined to form a recast layer having a surface hardness that is higher than the instrument blank material. Or the instrument blank can be twisted at a low temperature after forming it by the EDM or ECM process. <P>COPYRIGHT: (C)2004,JPO |
