Periodontally compromised implant patients demonstrate higher biological complication rates. A 10-year prospective study of ITI® Dental Implants

Objectives: The aim of this 10-year prospective study (observation time 8-15, mean: 10 years) was to compare failure and complication rates in patients having lost their teeth due to periodontitis (group A) or other reasons: caries, fracture, anodontia, trauma (group B). Methods: In 52 patients 112 Hollow Screws (HS) ITI® Dental Implants were placed (group A: 8 patients with 21 implants, group B: 44 patients with 91 implants). At 1, 5 and 10 years (age of the patients 30-88 years, mean age 61) after surgery clinical and radiographic parameters were assessed. The incidences of periimplantitis were noted over the 10 years of maintenance. Success at 10 years was set at: PPD< 5mm, BOP- and bone loss < 0.2mm per year. Results: Survival rates for ITI Hollow Screws(HS) were: 90.5% (group A) and 96.5% (group B) (Kaplan-Meier method). Group A had significantly more incidences of periimplantitis at HS (group A 37%, group B 11%) (Kaplan-Meier method, Log rank and Wilcoxon tests, p<0.0001). With the success criteria set, in group A 52.4% and in group B 79.1% of the HS were successful (Fisher's Exact test, p<0.03). With a threshold set at PPD<6mm, BOP-, and bone loss<0.2mm per year the success rates increased to 62% and 81.3% respectively. Relying on purely clinical parameters: PPD<5mm and BOP-, success rates increased to 71.4% and 94.5% and with PPD<6mm and BOP-, they increased to 81% and 96.7% respectively. Conclusions: Over 10 years, implants replacing teeth lost due to periodontitis demonstrated more biological failures and complications than implants replacing teeth lost due to other reasons. Setting of thresholds for success criteria is crucial for reporting on success rates. This study was supported by the Clinical Research Foundation, Bern, Switzerland and the Papavramides Foundation, Universities of Athens, Greece and Bern, Switzerland.