ObjectiveThe aim of the present prospective cohort study is to evaluate clinical and microbiological data of dental implants after at least 8years of follow-up. Material and methodsA total of 110 patients and 232 implants were included at baseline and followed during 1year. Fifty-two patients and 108 implants could be evaluated at the final examination. Clinical and microbiological data were taken at baseline, 1year and at least 8years. ResultsThe mean follow-up time was 10.81.7years. Plaque index was, respectively, 0.50 +/- 0.50 at baseline, 0.50 +/- 0.50 at 1year and 0.33 +/- 0.67 at 8years. Gingival index was, respectively, 1.08 +/- 0.19 at baseline, 1.01 +/- 0.39 at 1year and 0.22 +/- 0.47 at 8years. Sulcular bleeding index was, respectively, 0.17 +/- 0.22 at baseline, 0.11 +/- 0.33 at 1year and 0.17 +/- 0.22 at 8years. Probing depth was, respectively, 2.67 +/- 0.75 at baseline, 3.00 +/- 0.83 at 1year and 2.74 +/- 1.00 at 8years. Clinical attachment level was, respectively, 3.75 +/- 1.17 at baseline, 4.00 +/- 1.06 at 1year and 4.00 +/- 1.17 at 8years. Peri-implant mucositis was detected around 60.2% of implants in 73.1% of patients, while peri-implantitis was affecting 12% of implants in 15.4% of patients. Some bacteria species were associated with worsened clinical parameters. ConclusionsAbout 69.4% of implants (75/108) and 67.3% of the patients (35/52) were considered as success in the present prospective cohort study after a mean follow-up of 10.8years. Microbial follow-up may help to identify patients at risk for peri-implant disease.