Establishment of a Rat Peri-Implantitis Model via Maxillary Titanium Implant Placement and Porphyromonas gingivalis-Ligature Induction.

Peri-implantitis (PI) is a leading cause of dental implant failure, characterized by inflammatory soft tissue lesions and progressive bone loss, necessitating reliable animal models for mechanistic and therapeutic research. This study established a novel rat model that synergistically combines mechanical irritation with bacterial infection to better mimic the pathogenesis of human PI. Following the extraction of the maxillary first molars in 12 male Sprague-Dawley rats (4-week-old) and an 8-week healing period, titanium implants were placed. After 4 weeks of osseointegration, the PI group (n = 6) received ligatures soaked with Porphyromonas gingivalis (P. gingivalis) around the implant necks, while the negative controls (NC) group (n = 6) received no ligature treatment. Two weeks post-induction, analyses via Micro-computed tomography (micro-CT) and histology revealed significant alveolar bone loss and severe soft tissue inflammation, including marked inflammatory cell infiltration and tissue destruction, in the PI group compared to the NC group. This validated model effectively recapitulated key features of clinical PI. Its limitations include a simplified mono-pathogen challenge and an accelerated disease course compared to human PI. Nonetheless, it provides a robust and clinically relevant tool for investigative and therapeutic studies.