目的:探讨不同浓度的氯已定在牙龈卟啉单胞菌W83(P.gingivalis W83)引起的大鼠牙周炎模型中的抑制作用。方法:采用P.gingivalis W83灌饲和钢丝结扎牙颈部的方法建立大鼠牙周炎模型,在建立模型的过程中,采用0.05%、0.1%、0.2%和0.5%的氯已定冲洗大鼠牙周袋及口腔黏膜,4周后,绝对实时定量PCR检测各组大鼠牙周袋内的P.gingivalis W83拷贝数,扫描电镜观察各组大鼠牙齿表面的P.gingivalis W83定植情况。免疫组织化学技术检测大鼠牙龈组织中TNF-α的表达(P<0.05)。结果:0.2%和0.5%的氯已定能够有效减少大鼠牙周袋内及牙齿表面的P.gingivalis W83数量(P<0.05);0.1%~0.5%的氯已定能够减少大鼠牙龈组织中TNF-α的表达(P<0.05)结论:0.1%~0.2%的氯已定能够抑制大鼠慢性牙周炎的进展。 OBJECTIVE: To investigate the inhibitory effect of different concentrations of chlorhexidine in the rat periodontitis model induced by P. gingivalis W83 (P.gingivalis W83). Methods: The model of periodontitis in rats was established by feeding P. gingivalis W83 and ligating the cervical part of the rat with steel wire. During the establishment of the model, 0.05%, 0.1%, 0.2% and 0.5% Four weeks later, the P. gingivalis W83 copy number in the periodontal pocket of rats in each group was detected by absolute real-time PCR. The deposition of P. gingivalis W83 on the surface of rat teeth was observed by scanning electron microscopy. Immunohistochemistry was used to detect the expression of TNF-α in the gingival tissues of rats (P <0.05). Results: 0.2% and 0.5% of chlorhexidine could effectively reduce the number of P.gingivalis W83 in the periodontal pocket and the tooth surface of rats (P <0.05); 0.1% -0.5% of chlorhexidine could reduce the gingival tissue of rats (P <0.05) Conclusions: 0.1% ~ 0.2% Clodronine can inhibit the progression of chronic periodontitis in rats.