Regulatory Effect Of Orthodontic On TLR4/NF-?B Signaling Pathway In Periodontal Tissue Of Gingivitis Rats

ObjectiveTo investigate the effect of orthodontics on the expression of TLR4/NF-?B signaling pathway in periodontal tissues of gingivitis rats by constructing an orthodontic animal model.It provides experimental basis for the orthodontic treatment of clinical gingivitis patients.Research method1.One hundred rats were randomly divided into four groups,including normal control group,gingivitis group,normal force 50g group,gingivitis force 50g group?experimental group?,25 rats in each group.After gingivitis model was established by silk ligation,orthodontic Ni-Ti spiral tension spring was used to build force model.All rats were executed at the 1^st,3^rd,5^th,7^th,and 14^thh day,and then the periodontal tissues in the pressure sides of the rat experimental area were taken.2.To observe whether the rat gingivitis afterforce model was successfully constructed by naked eye and microscope.3.The concentration of interleukin-1??IL-1??,interleukin-6?IL-6?and tumor necrosis factor?TNF-??in rat periodontal tissues were measured by enzyme-linked immunosorbent assay?ELISA?.4.The mRNA expression levels of TLR4 and NF-?B p65 in rats'periodontal tissues were measured by Real-time PCR.5.HE staining was used to verify whether the gingivitis model was successfully constructed and to observe the degree of inflammation of the gingival epithelium at each postloading time point in rats.6.The protein expression levels of TLR4 and NF-?B p65 in rats'periodontal tissues were measured by immunohistochemical.Results1.The rat gingivitis afterforce model was successfully constructed:hyperemia and redness of the gingival mucosa were observed with the naked eye,and the rats were prone to bleeding on examination,but the loss of periodontal adhesion level was not observed.Microscopically,the epithelial nils were serrate with abundant lymphocytes and neutrophils infiltrating the lamina propria connective tissue.The distance of the first molars moving near the middle is proportional to the time it takes to apply the force.2.The concentration of IL-1?,IL-6 and TNF-?in rats'periodontal tissues with gingivitis in the experiment group was higher than that of the rest of 3group,and the difference was statistically significant?P<0.05?.3.The results of real-time PCR showed that the expression of TLR4 and NF-?B p65mRNA in rats'periodontal tissues of rats with gingivitis in the experiment group was also higher than that of the rest of group,the difference was statistically significant?P<0.05?.The expression of TLR4,NF-?B p65 show a normal distribution.And the 5th day was the peak of TLR4 expression.Day 7 was the peak of NF-?B p65 expression.4.HE staining showed that the degree of gingivitis was the highest in the gingivitis afterforce group.5.Immunohistochemical results showed that the expressions of TLR4 and NF-?B p65 in the periodontal tissues of rats in the experimental group were significantly higher than those of other groups?P<0.05?,and the expression of TLR4 and NF-?B p65 in the normal control group was negative.Conclusion1.Under the action of orthodontic force,the TLR4/NF-?B signaling pathway in the periodontal tissues of gingivitis rats is activated,and orthodontic force can promote the opening of the TLR4/NF-?B inflammatory signaling pathway in the periodontal tissues of rats.2.The opening of TLR4/NF-?B signaling pathway will aggravate the local inflammatory response of periodontal tissues in orthodontic treatment,and produce a large number of downstream inflammatory factors such as IL-1?,IL-6,TNF-?,which will aggravate gingival inflammation and delay the normal orthodontic treatment.3.In this study,the expression of TLR4/NF-?B signaling pathway in periodontal tissues of gingivitis rats was preliminarily investigated,which provided experimental basis for further study of TLR4/NF-?B signaling pathway inhibitors.4.This study successfully constructed an animal model of gingivitis orthodontic,providing a basis for clinical gingivitis patients to choose the right treatment time,gingivitis patients should wait for gingivitis control before orthodontic treatment.