| 摘要 |
<p>The bur (1) has a dental coupling (2), a bur shank (3), a bur neck (4) with a helical groove and a corresponding bevel, and a bur tip (5) with a tip cutting edge (7), where the tip cutting edge is partly rounded. The cutting edge has edges as a part of an imaginary cone with an axis that runs through another axis of the bur, and roundings as a part of an imaginary sphere with a center located on the axis of the bur, where the edges form an angle of about 140 to 180 degrees between the edges. A set of markings is provided on the bur for indicating the drilling depth.</p> |
