| 摘要 |
The pin comprises a threaded portion (11) for self-tapping insertion in a bore formed in tooth dentine, a frusto-conical shoulder portion (16), a shank (12) with at one end a flat (14) and annular groove (15) so that the pin can be latched in a standard contra-angle handpiece, and an undercut (19) permitting the shank (12) to automatically separate from the remainder of the pin. The pin is handpiece-inserted into said bore in the tooth dentine and when the shoulder (16) engages a correspondingly shaped portion of the cast restoration, the undercut (19) automatically shears-off. The pin can be finally hand-tightened by engaging a hand-wrench on the shaped portion (18). |
