Long-Term Incidence of Peri-Implant Conditions: 25-Year Results of The Bernese Prospective Cohort Study

To assess 25-year implant survival, success rates, peri-implant conditions, and variables influencing peri-implant mucositis (PM), peri-implantitis (PI), and loss of osseointegration.

Partially edentulous patients rehabilitated with tissue-level implant-supported prostheses were evaluated. Calibrated examiners performed clinical and radiographic assessments, and potential variables for PM and PI were analyzed at the final follow-up.

At the 10- and 25-year follow-ups, 303 and 159 patients with 511 and 252 implants, respectively, were included. Implant failure (IF) was 1.2% at 10 years and 6.0% at 25 years, with implant survival rates of 98.8% and 94.0%, respectively (p < 0.001). Implant success rates ranged from 97.0% at 10 years to 90.8% at 25 years (p < 0.001). IF due to loss of osseointegration increased from 0.6% to 3.6% at the implant level and from 1.0% to 2.5% at the patient level, and were located only in premolar or molar sites. At implant level, peri-implant health (PH) was 14.4% at 10 and 25 years (p = 1.00), while PM decreased from 82.1% to 76.5% (p = 0.08), and PI increased from 3.5% to 9.1% (p = 0.001). At patient level, PH remained stable between 10 and 25 years, ranging from 10.0% to 10.3% (p = 0.94), while PM decreased from 80.0% to 71.6% (p = 0.06), and PI increased from 10.0% to 18.1% (p = 0.01). In the multivariate analysis, history of periodontitis (OR = 3.87) and facial mucosal thickness (OR = 0.42) were associated with PM, whereas facial mucosal thickness was associated with PI (OR = 0.02).

After 25 years, implant survival and success exceeded 90%. Loss of osseointegration accounted for approximately 60% of IF. While PI and IF increased over time, PM decreased but remained prevalent.