Peri-implantitis is an inflammatory process around dental implants, which includes the destruction of peri-implant bone and may lead to implant loss. The prevalence of patients who present with peri-implantitis is between 28% and 45%, and this poses a substantial problem for patients and dental professionals. There is no detailed understanding of the pathogenesis of peri-implantitis, nor are there effective treatment protocols for it.
Objective: Create a murine model to study the pathogenesis of peri-implantitis.
Methods: Maxillary left molars were extracted on 20 mice. Eight weeks after extractions, titanium implants were placed in the first/second molar region. Four weeks later, osseointegration was confirmed clinically and by micro-CT after sacrificing six animals. On the remaining mice, peri-implantitis was induced by inserting silk ligatures around the head of the implant fixtures. Implant survival and bone loss were analyzed clinically and by micro-CT at twelve weeks after ligature placement.
Results: At four weeks after implantation, implants that were placed in mice and that did not receive ligatures presented with mucosal tissues that were clinically healthy and no space between the most coronal bone level and the head of the implant.
At twelve weeks after peri-implantitis was initiated via ligature placement, the implant survival rate was 40% in the treatment versus 100% in the control group. At sacrifice, the ligature-treated group presented with clinical signs of peri-implant mucosal inflammation, which were absent in the control group. In addition, micro-CT analysis the ligature-treated group revealed that they lost significantly more peri-implant bone than the control group (p<0.001).
Conclusions: The placement of silk ligatures around implants resulted in the induction of peri-implantitis. The availability of a murine model should allow us to dissect the pathogenic pathways involved in peri-implantitis and aid in developing preventive and treatment approaches for the disease.