A prospective multicenter clinical study of the osseotite implant: Four-year interim report

This article reports the 4-year interim results of a multicenter study eval uating the clinical performance of the Osseotite dental implant. At 4 study centers, 485 Osseotite implants were consecutively placed in 181 patients (219 were placed in the mandible and 266 in the maxilla). A total of 355 im plants were placed in posterior regions. Short implants (10 mm or less) rep resented 31.5% (n = 153) of all implants placed in this study. Patients wer e restored with 210 restorations, distributed as 123 short-span prostheses, 58 single-tooth replacements, 28 long-span prostheses, and 1 maxillary ove rdenture. At this 4-year interim evaluation, the mean time from implant pla cement to the most recent evaluation was 52.6 +/- 3.0 months, with a mean l oading time of 43.3 +/- 3.8 months. Of the 485 implants placed, there have been 6 failures. All implant failures occurred prior to loading and were ca tegorized as early implant failures. Five of the 6 failures occurred in the maxilla. Only one of the 153 short implants failed to integrate. Baseline radiographs were obtained at prosthesis connection. Radiographic analysis 1 year post-restoration showed a mean bone loss of 0.09 +/- 0.7 mm. From bas eline to the end of the second year of function, an overall mean bone loss of 0.13 +/- 0.8 mm was recorded, indicating no additional bone was lost aft er the first year of implant function. At 4 years, the cumulative implant s uccess rate for all implants placed in this study was 98.7%, with a 99.4% s uccess rate in the posterior mandible and 98.4% success rate in the posteri or maxilla. Results of this 4-year interim analysis indicate that this impl ant achieved a high success rate in posterior regions and that all failures with this implant in this patient population occurred prior to implant loa ding. When the clinical success of implants 10 mm or shorter was compared t o that of implants greater than 10 mm in length, the shorter implants in th is study performed similarly to longer implants.