| 摘要 |
The disclosure relates to an apparatus for the fixation of a single-tooth restoration to an implant in the form of an anchorage element (fixture) permanently anchored in the maxillary, comprising a substantially tubular spacer (4) which is anchored to the anchorage element by means of a spacer screw (5) provided with an externally threaded portion (23) which engages in an internally threaded recess (7) in the upper region of the fixture. The spacer screw (5) is provided with an unthreaded waist (25) whose length exceeds the thread diameter of the spacer screw, and has a screw head (20) of comparatively slight diameter and with a planar or gently conical shoulder which cooperates with a corresponding annular shoulder (19) in the tubular spacer (4). The apparatus is mounted in place by means of a double screwdriver whose one part fits the internal counter-abutment in the spacer sleeve (4) and whose other part is caused to engage with the driver slot (24) of the screw head. In the mounting operation, equal, but counter-directed torques are applied to both parts of the screwdriver so that the implant will remain unloaded during the mounting operation proper. |
