关键词: 牙周炎, 银离子抗菌液, IL-6, TNF-α, TGF-β

Abstract: Objective To observe the expression of interleukin-6 （IL-6）, tumor necrosis factor-α （TNF-α） and transforming growth factor-β （TGF-β） in periodontal tissues of rats with experimental periodontitis and to explore the therapeutic effect of silver ion on periodontitis after establishment of the animal model of experimental periodontitis by ligating the periodontium of rats, and administration of active silver ion antibacterial solution to perriodontium.  
Methods A total of 70 purebred, healthy, 6-month-old male SD rats were selected, and 10 rats were randomly selected for periodontitis model identification by ligating the tooth neck of maxillary bilateral first molars. After successful periodontal ligation and establishment of periodontitis models in 60 rats, they were randomly divided into three groups, namely, physiological saline group 1 (n=20), iodoglycerin group 2 (n=20), silver ion group 3 (n=20) with physiological saline, iodoglycerin, and active silver ion antibacterial solution injected in periodontal pockets of rats, respectively. At 4 weeks after treatment, 10 rats from each group were randomly selected and sacrificed, and maxillary bone specimens were taken for sectioning and staining for observation and analysis. The remaining 10 rats in each group were treated with periodontal ligature removal, and the same administration method was used. Physiological saline group 2, iodoglycerin group 2, silver ion group 2 were given physiological saline, iodoglycerin, and active silver ion antibacterial solution, respectively. At 4 weeks after treatment, all rats were sacrificed, and maxillary bone specimens were taken for sectioning and staining for observation and analysis. 
Results Observation of the joint sections of the tooth body and periodontal tissue of the rat maxillary first molar was performed under histological light microscopy. At 4 weeks after ligation, an increase in epithelial nail processes was observed, and inflammatory cell infiltration was observed in the connective tissue. Combined with epithelial proliferation towards the root, periodontal pockets were formed, with disordered arrangement of periodontal fibers and resorption of alveolar bone. An animal model of experimental periodontitis in rats was successfully established. At 4 and 8 weeks after ligation and administration, the OD values of IL-6 and TNF-α in iodoglycerin group 1 and 2 and silver ion group 1 and 2 were lower than those in physiological saline group 1 and 2, and the OD value of TGF-β was higher than that inphysiological saline group 1 and 2, with a statistically significant difference (P＜0.05). The OD value of IL-6 in silver ion group 1 and 2 was lower than that in iodoglycerin group 1 and 2, while the OD value of TGF-β was higher than that in iodoglycerin group 1 and 2, and the difference was statistically significant (P＜0.05). The OD value of TNF-α in iodoglycerin group 1 and 2 and silver ion group 1 and 2 was not statistically significant (P＞0.05). 
Conclusion Experimental rat model of periodontitis has been successfully established by wire ligation of tooth neck of maxillary bilateral first molars. The active silver ion antibacterial solution can inhibit the expression of IL-6 and TNF-α, and promote the expression of TGF-β in the periodontal tissue of periodontitis rats. By exploring the correlation between three factors and periodontal inflammation, we can provide a new basis for the research of the pathogenesis of periodontitis. 

Key words: periodontitis, silver ion antibacterial solution, IL-6, TNF-α, TGF-β