| 摘要 |
The screw driver esp. for use by dentists to cap broken teeth, has a thin pin with a self-tapping thread. At the extreme end the pin is joined to the screw driver body by a waisted portion which forms a weak link and breaks when the pin is fully screwed into position. The main body of the screw driver with the knurled knob at the other end can then be thrown away. This facilitates the insertion of retaining pins and assists in the handling of the fine pins of 0.5-0.6 mm. dia. The weak link prevents any excessive torque application. This manual screw driver can be used anywhere in the mouth of a patient and is not restricted like mechanised drives. |
