Development of a peri-implantitis model in New Zealand white rabbits: A preclinical study

There is an urgent need for an effective infection model to distinguish peri-implantitis from periodontitis because of the limited understanding and differing pathogenesis of these diseases.

The purpose of this preclinical study was to establish a peri-implantitis model using New Zealand White rabbits, develop implants suitable for small animals, simulate implantation and healing, and evaluate peri-implantitis progression and healing outcomes.

Self-developed titanium implants were inserted bilaterally into the maxillae of New Zealand White rabbits and allowed to heal for 4 weeks. After osseointegration, a peri-implantitis model was created by using an orthodontic ligature. The animals were divided into inflammation and antibiotic treatment groups. Inflammation progression, bone defects, and regeneration were analyzed by using microcomputed tomography (µCT) and immunohistochemistry. Groups were compared using the t test or 1-way analysis of variance for more than 2 groups.

The implants achieved osseointegration after 4 weeks, establishing a stable peri-implantitis model. The µCT analysis showed that horizontal bone absorption accounted for 31.25%, vertical absorption for 12.50%, and combined absorption for 56.25% of the defects. Circular defects were the most common, accounting for 60% of all the defects. Linear and peri-implant bone defect volume measurements revealed a significant reduction in bone defects and increased implant stability quotient values after antibiotic treatment (P<.01). Histological staining showed reduced inflammation and increased trabecular bone structure after antibiotic treatment. Immunohistochemical analysis indicated the increased expression of osteogenic-related proteins and decreased tartrate-resistant acid phosphatase staining in osteoclasts after antibiotic treatment.

A rabbit model of peri-implantitis was successfully established. This study provided a novel animal model for future studies on peri-implantitis and the development of new treatment modalities.