Outcome of Single Dental Implants Over 38-40 Years: A Long-Term Follow-Up Study.

INTRODUCTION: This is a comprehensive, long-term follow-up study of single-implant treatments. At the Branemark Clinic in Gothenburg, Sweden, during the period of 1982-1985, 16 patients received single-tooth implants. OBJECTIVE: This study evaluates the survival rate of the implants after nearly four decades, focusing on the biological and technical complications. METHODS: Of the original 16 patients with a total of 23 implants, 13 patients with 18 implants were available for the follow-up and were included in the study. Clinical and radiographic examinations were performed on these patients. RESULTS: The cumulative survival rates were 95.6% for the implants and 60.9% for the implant-supported crowns after 38-40 years in function. The marginal bone level changes were 0.9 +/- 1.0 mm (range, -0.5 horizontal line 3.0 mm) over the follow-up period. The frequency of biological complications was low; although mucositis was common, no cases of peri-implantitis were observed. The mean plaque index was 16.9% +/- 11.6% (range, 1% horizontal line 34%) and the mean probing depth around the implants was 3.8 +/- 2.2 mm (range, 0.0 horizontal line 7.0 mm). Few technical complications were observed, although many of the original implant-supported crowns had been replaced for esthetic reasons. CONCLUSION: The findings emphasize the importance of long-term follow-up in implant dentistry, particularly for younger patients, to improve understanding of potential complications and the longevity of treatment outcomes. Overall, single-tooth implants have a favorable long-term prognosis, though crown replacement may eventually be necessary.