Despite a relatively high long-term survival rate, biological and technical complications were frequent. Patients with a history of periodontitis may have lower implant survival rates than patients without a history of periodontitis and were more prone to biological complications such as peri-implant mucositis and peri-implantitis.

These data indicate that Pg infection worsened periodontal tissue destruction through specific pathogenic pathways and modified systemic response to periodontal inflammation. Furthermore, the blood cytokine response to ligature models showed their relevance for evaluating the systemic impact of periodontal disease.