摘要Background:Although widely used in periodontal research,rodents are naturally re-sistant to periodontitis.Conventional models,such as ligature-induced periodontitis,often fail to sustain defects due to spontaneous tissue regeneration after ligature removal.To address this,we refined a rat ligature-induced model of experimental periodontitis to better mimic the chronic,progressive nature of human periodontitis.Methods:As a first step,following a split-mouth design,we compared the effective-ness of 3/0 silk thread and 0.008-inch orthodontic wire as ligature materials.Ligatures were applied around the left mandibular first molar for 6,10,and 14days.Periodontal pocket irrigation was performed every second day using a suspension of P.gingivalis,P.intermedia,and S.gordonii.As a second step,we evaluated whether silk-ligature alone,without human periopathogens,would be sufficient to induce a stable and progres-sive periodontal lesion.For that purpose,a silk ligature was removed on day 14,and the bone defect dynamics were monitored at 14-,21-,and 28-days post-removal using micro-CT.Results:Both wire and silk ligatures,in combination with bacterial irrigation,effec-tively induced rapid interproximal alveolar bone loss.However,silk ligature only,without periodontopathogen colonization,resulted in significantly lower bone loss(1.076±0.22mm vs.2.012±0.374mm;p=0.003)and the induced alveolar bone de-fects gradually resolved again over time.Conclusions:The proposed rat model of periodontitis is well characterized and repli-cates human disease by sustaining colonization with viable periopathogens,leading to progressive disease with alveolar bone loss.The suggested model is straightforward,easy to establish and can be used reliably in preclinical studies.