| 摘要 |
PROBLEM TO BE SOLVED: To provide an instrument wherein elimination capability is held even if pressing a diamond bar for a rotary bone elimination instrument in the axial direction, and which is safe even if the instrument is used for a nerve operation.SOLUTION: This diamond bar includes a concavity 9 conically cut out in a small range having the tip rotational axis center of a spherical bar as the center. By applying abrasive grain fixing working onto the whole surface of the bar 8 including the concavity surface, it is solved that the tip rotational axis center having lowest cutting capability comes to the forefront of the cutting, so that the cutting becomes rapid. When advancing bone elimination, a bone abuts on the rotational axis center, too, but the bone having remained in the shape of the concavity portion without being cut is weak on a structure because it is a small projection shape, and is easily scraped. |
