Ligature-induced peri-implantitis in mice

Abstract

Background and objective: Peri-implantitis has a prevalence of 11-47%, involves destruction of peri-implant bone and may lead to implant loss. A detailed understanding of the pathogenesis of peri-implantitis is lacking. The objective of this study was to develop a murine model of experimental peri-implantitis.

Material and methods: Machined, smooth-surface, screw-shaped titanium implants were placed in the healed alveolar bone of the left maxillary molars of C57BL/6J male mice, 8 wk after tooth extraction. Peri-implantitis was induced by securing silk ligatures around the head of the implant fixtures. Implant survival and peri-implant bone levels were analyzed by micro-computed tomography (micro-CT) scans and histology, 12 wk after ligature placement.

Results: Implant survival was 60% (six of 10) for implants with ligatures and 100% (eight of eight) for controls. Micro-CT revealed significantly greater bone loss around the implants that received ligatures and that survived, compared with controls. The radiographic findings were confirmed via histology and toluidine blue staining.

Conclusion: This study describes a murine model of experimental peri-implantitis around screw-shaped titanium implants placed in the edentulous alveolar bone. This model should be a useful tool to dissect pathogenic mechanisms of peri-implantitis and evaluate potential treatment interventions.

Keywords: animal model; bone loss; dental implant; peri-implantitis.

Figure 1. Research design

Schematic diagram depicting timing of the experimental design.

Figure 2. Peri-implantitis Development

A) Representative clinical images of the control (left) and experimental (right) groups at twelve weeks after ligature placement. B) Representative sagittal micro-CT images of control (left) and experimental (right) groups. Notice the reduced alveolar bone level on the experimental specimen. C) Graph representing the average distance of the implant head to the alveolar bone. Data are mean ± standard error of the mean. Left bar (a) corresponds to the control group, middle bar (b) corresponds to the experimental group excluding lost implants and right bar (c) corresponds to the experimental group including the lost implants. ***p<0.001 comparing control (a) (n≥8) and experimental groups (b and c) (n≥6, and n≥10, respectively). + p<0.05 comparing groups b and c. D) Representative histological sample stained with toluidine blue twelve weeks after ligature placement in the control (left) and experimental group (right). Notice reduced alveolar bone level and supra-crestal inflammatory infiltrate on experimental specimen.