Peri-implantitis and periodontitis. Experimental and clinical studies

Peri-implantitis is an increasing problem in implant dentistry. The current series of studies employed a translational approach with the aim to compare peri-implantitis and periodontitis lesions and evaluate the influence of implant surface characteristics and the adjunctive use of systemic antibiotics/local antiseptics on healing following surgical treatment of peri-implantitis. Tissue reactions following ligature removal in experimental periodontitis and peri-implantitis were analyzed in a dog model (Study I). Histopathological characteristics in human peri-implantitis and periodontitis lesions were evaluated in 80 patients (Study II). Labrador dogs were used to analyze the effect of surgical treatment of experimental peri-implantitis at implants with different surface characteristics using different anti-infective procedures (Study III). 100 patients with severe peri-implantitis were treated surgically with or without adjunctive systemic antibiotics or the local use of chlorhexidine for implant surface decontamination. Treatment outcomes were evaluated after 1 year. A binary logistic regression analysis was performed to identify factors influencing the probability of treatment success (Study IV). It was demonstrated that : the amount of bone loss that occurred during the period following ligature removal was significantly larger at implants with a modified surface than at implants with a non-modified surface and at teeth. The histological analysis revealed that peri-implantitis sites exhibited inflammatory cell infiltrates that were larger, extended closer to the bone crest and contained larger proportions of neutrophil granulocytes and osteoclasts than in periodontitis. (Study I) peri-implantitis lesions were more than twice as large and contained significantly larger area proportions, numbers, and densities of CD138-, CD68-, and MPO-positive cells than periodontitis lesions. (Study II) the local use of chlorhexidine has minor influence on resolution of peri-implantitis following surgical treatment. (Study III) treatment outcome was influenced by implant surface characteristics. (Study III and IV) the adjunctive use of systemic antibiotics increased the probability for treatment success at implants with modified surfaces but not at implants with a non-modified surface. (Study IV