Abstract:Objective: To establish an experimental animal model of peri-implantitis after immediate implantation of mandibular anterior teeth in rabbits. Methods: A total of 12 healthy male rabbits were anesthetized in the study. A tapered titanium implant was inserted immediately after removal of the left mandibular anterior tooth in each rabbit. Three rabbits were randomly selected and executed after 8 weeks of implantation. Micro-CT was used to evaluate the osseointegration. Then, the rest of animals were randomly divided into three groups. The blank group was not given stimulation, while the control group and the experimental group were injected phosphate buffer solution and E.coli-LPS solution around the implant respectively. After 2 weeks of stimulation, all rabbits were sacrificed to collect the mandible samples with implants and gingival tissues. Micro-CT was used to evaluate bone mass around implants, and hematoxylin and eosin staining was used to observe the histological changes of gingival tissues. Results: After 8 weeks of implantation, satisfactory osseointegration of implants were formed with healthy gums. After 2 weeks of stimulation, the blank and control groups showed pink tough gums with scattered inflammatory cells and good osseointegration of implants without bone resorptions. The experimental group showed red swollen gums with massive inflammatory cells and apparent bone resorptions on the top of implants with reduced bone mineral density and percent bone volume. Conclusion: An experimental animal model of peri-implantitis in rabbits could be established rapidly by local injections of E.coli-LPS solution around the implant.