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Implant-supported single-tooth restorations. A 12-year prospective study.

OBJECTIVE
The aim of this study was to evaluate prospectively the 12-year outcome of implant-supported single-tooth restorations.


MATERIAL AND METHODS
Originally 45 self-tapping Astra Tech TiOblast® ST-implants were installed by a two-stage protocol in 40 subjects requiring single-tooth prosthetic replacement for a missing tooth. Clinical and radiologic examinations were performed at completion of the prosthetic treatment 4-7 months after implant installation surgery and after 5 and 12 years in function.


RESULTS
At 12 years 31 patients and 35 implants were available for evaluation. The overall failure rate after 12 years was 10.3% on the subject level and 9.1% on the implant level. The mean bone loss amounted to 0.67 mm (SD 2.20) on a subject level and 0.47 mm (1.72) on an implant level. Three subjects (10%) and three implants (8.6%) were diagnosed with peri-implantitis. Five subjects had experienced technical complications; three incidences of loosening of the abutment retention screw during the first 5 years and two minor porcelain fracture of the crown (two patients) between 5- and 12-years of follow-up.


CONCLUSION
The findings reported in this 12-year prospective case series suggest that the use of the Astra Tech dental implants may be a valid treatment alternative for single-tooth replacement prostheses.