Long-term prospective cohort study on dental implants: clinical and microbiological parameters

The aim of the present prospective cohort study is to evaluate clinical and microbiological data of dental implants after at least 8 years of follow-up.

A total of 110 patients and 232 implants were included at baseline and followed during 1 year. Fifty-two patients and 108 implants could be evaluated at the final examination. Clinical and microbiological data were taken at baseline, 1 year and at least 8 years.

The mean follow-up time was 10.8 ± 1.7 years. Plaque index was, respectively, 0.50 ± 0.50 at baseline, 0.50 ± 0.50 at 1 year and 0.33 ± 0.67 at ≥8 years. Gingival index was, respectively, 1.08 ± 0.19 at baseline, 1.01 ± 0.39 at 1 year and 0.22 ± 0.47 at ≥8 years. Sulcular bleeding index was, respectively, 0.17 ± 0.22 at baseline, 0.11 ± 0.33 at 1 year and 0.17 ± 0.22 at ≥8 years. Probing depth was, respectively, 2.67 ± 0.75 at baseline, 3.00 ± 0.83 at 1 year and 2.74 ± 1.00 at ≥8 years. Clinical attachment level was, respectively, 3.75 ± 1.17 at baseline, 4.00 ± 1.06 at 1 year and 4.00 ± 1.17 at ≥8 years. 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.

About 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 10.8 years. Microbial follow-up may help to identify patients at risk for peri-implant disease.