Experimental periodontitis and peri‐implantitis in dogs

AIM: To analyze the tissue reactions following ligature removal in experimental periodontitis and peri-implantitis in dogs. MATERIAL AND METHODS: Four implants with similar geometry and with two different surface characteristics (turned/TiUnite Nobel BioCare AB, Göteborg) were placed pair-wise in a randomized order in the right side of the mandible 3 months after tooth extraction in 5 dogs. Experimental peri-implantitis and periodontitis were initiated 3 months later by ligature placement around implants and mandibular premolars and plaque formation. The ligatures were removed after 10 weeks, and block biopsies were obtained and prepared for histological analysis 6 months later. RESULTS: 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 turned 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. CONCLUSION: It is suggested that lesions produced in experimental periodontitis, and peri-implantitis are different and that implant surface characteristics influence the inflammatory process in experimental peri-implantitis and the magnitude of the resulting tissue destruction.