抄録
This paper analyzes clinical application of the Brånemark system implant® over the 10 years from 1989 to 1999, especially the 17 of 126 patients where fixtures were later removed. A total 515 fixtures were installed, and 32 fixtures were removed; the 10-year cumulative survival rate of the fixtures was 93.2%. Thirty-two fixture removals were conducted:16 at the time of second-stage surgery, 12 during use of a temporary prosthesis, and 4 after final prosthesis installation. Maxillary removal accounted for 18 fixtures. Of these, 17 were posterior maxillary. The remaining 14 fixtures were mandibular removals. In cases in which the posterior maxilla was more than 4 mm in diameter and 13 mm in length, the survival rate was a low 66.7%, with more than half of the patients exhibiting bone quality of 3 or 4 (LEKHOLM＆ZARB).
In cases in which osseointegration was attained, the fixture's survival rate was good even after the installation of a final prosthesis. However, the finding that a significant number of patients exhibited bone quality issues in the posterior maxilla, requires reconsideration of both surgical procedures and the type of fixture itself.
