| Objective: Experimental periodontitis and passive smoking model of the ratswas established by periodontal ligation and using smoking box, the treatment ofthe rats was gavaged by quercetin. Observe the morphological change of theperiodontal tissue and detect the expression of the COX-2, TNF-α byimmunohistochemical method in the periodontal tissue after eight weeks. Discussthe effect of passive smoking on the periodontal tissue and the protective effectof quercetin on the periodontal tissue of periodontitis and periodontitis withpassive smoking in Wistar rats.Methods: Seventy6-month-old male Wistar rats were randomly divided intoseven groups: normal control group(group N), passive smoking group(group P),ligation group(group L), ligation+quercetin group(group LQ), ligation withpassive smoking (group LP), quercetin+ligation with passive smoking andquercetin group(group LPQ). Every group was ten. The control group was raisedwith no treatment. The rats of group L, LQ, PL, PLQ were anesthetized, and thenwere ligated by a wire diameter of0.2mm around the cervical of the bilateralmaxillary first molar. The rats of group LQ, LPQ were treated with quercetin bygavage(50mg/kg). Given medicines after60minutes, the rats of group LPQ wereused to passive smoking intervention in a confined space(lighted cigarettes60minand10cigarettes once in the space). The rats of group P, LP were treated by usingpassive smoking. After8weeks, the rats were killed under general anesthesia, andthe maxillary were taken, put into10%formaldehyde buffer solution for fixing48hours, decalcified by10%EDTA solution for8weeks. Periodontal toothcontinuous slices was made for HE staining and immunohistochemistry staining.The morphological changes, the expression and distribution of TNF-α, COX-2inthe periodontal tissue were observed under light microscope. The date wasprocessed for statistical analysis. Results:1Establishment of the rat periodontitis model:Maxillary first molar periodontal slices were observed: ligated in8weeks,the rats were swollen gums, easy bleeding on probing, periodontal pocket.Under optical microscope: junctional epithelium moved to the root, andperiodontal pocket has formed; obvious gingival flammation infiltrated,shown inflammatory cells infiltration; periodontal fibers were disordered；thealveolar bone was absorbed and was eroded state; the osteoclasts were seen.All of them have indicated that: periodontitis of experimental model of ratshad been successfully established.2Pathology observation of the rat periodontal tissue:Normal group: Gingival papillae morphology basically complete.junctional epithelium was located in the cemento-enamel junction boundaries.Gingival epithelium had no significant infiltration of inflammatory cells,periodontal ligament fibers arranged orderly. The alveolar crest was notabsorbed.Passive smoking group: Junctional epithelium was located in thecementum-enamel junction boundaries. There are a little of inflammatorycells in connective tissue and light absorption of alveolar bone.Ligation group: Gingival epithelial spikes extend to the deep part ofconnective tissue. Junctional epithelium move to the root of the tooth, show,form a periodontal pocket, more inflammatory cells infiltration, fibers arrangebroken and regularly, the vascular distend in periodontal membrane,emergence of alveolar bone resorption, and show osteoclasts.Ligation with passive smoking group: Gingival papilla structure damage,junctional epithelium move to the root, the deep periodontal pocket form,some deep to apical1/3, extensive infiltration of inflammatory cells areshowed, some are lymphocytes predominance, vertical alveolar are significantabsorption.Ligation and quercetin group: Gingival papilla structure damage,junctional epithelium move to the root, the periodontal pocket form, the connective tissue have amount of inflammatory cell infiltration, new boneformation can be seen, osteoblasts reduce.Ligation with passive smoking and quercetin group: Inflammation of theperiodontal tissue alleviate, trench beneath the epithelium and lamina propriahave few inflammatory cell infiltration, and at the alveolar ridge, osteoblastscan be seen, new bone formation can also be observed.3The expression of TNF-α, COX-2in rat periodontal tissue3.1The expression and distribution of TNF-α in rat periodontal tissue:The positive staining of TNF-α in rat periodontal tissue was yellow orbrown granules which were located in the fibroblasts, osteoblasts and vascularendothelial cells. The OD of the six groups were: the normal group:0.129±0.008; the passive smoking group:0.142±0.011; the ligation group:0.174±0.012; the ligation with passive smoking group:0.289±0.012; theligation and quercetin group:0.154±0.009; the ligation with passive smokingand quercetin group:0.196±0.003.3.1.1The OD values of the passive smoking group were higher than thenormal group (P<0.05). The OD values of the ligation with passive smokinggroup were higher than the normal group (P<0.05).3.1.2The OD values of passive smoking group are higher than the normalgroup (P<0.05). The OD values of ligation with passive smoking group arehigher than the ligation group (P<0.05).3.1.3The OD values of ligation and quercetin group are lower than theligation group (P<0.05).3.1.4The OD values of ligation with passive smoking and quercetin group arelower than the ligation with passive smoking group (P<0.05)3.2The expression and distribution of COX-2periodontal tissue:The positive staining of COX-2in rat periodontal tissue was yellow orbrown granules which were located in the fibroblasts, osteoblasts. The OD ofthe six groups were: the normal group:0.120±0.015; the passive smokinggroup:0.136±0.014; the ligation group:0.182±0.008; the ligation with passivesmoking group:0.298±0.008; the ligation and quercetin group:0.143±0.002; the ligation with passive smoking and quercetin group:0.205±0.006.3.2.1The OD values of the passive smoking group were higher than thenormal group (P<0.05). The OD values of the ligation with passive smokinggroup were higher than the normal group (P<0.05).3.2.2The OD values of passive smoking group are higher than the normalgroup (P<0.05). The OD values of ligation with passive smoking group arehigher than the ligation group (P<0.05).3.2.3The OD values of ligation and quercetin group are lower than theligation group (P<0.05).3.2.4The OD values of ligation with passive smoking and quercetin group arelower than the ligation with passive smoking group (P<0.05).Conclusion:1A periodontitis model of rat had been successfully established by ligatedthe bilateral maxillary first molar teeth using the orthodontic wire and aperiodontitis with passive smoking model was established by using smokingbox.2The rats of passive smoking had more inflammatory cell infiltration andthe higher expression of TNF-α and COX-2than the normal group.Suggesting that passive smoking caused the change of inflammatory ofperiodontal tissues.3The rats of periodontitis with passive smoking had serious pocket depthinflammatory cell infiltration, alveolar bone resorption, the increaseexpression of TNF-α and COX-2. Suggesting that the passive smokingincreased the degree of the inflammation of periodontal tissues.4The inflammation of periodontal tissue of periodontitis and periodontitiswith passive smoking were reduced by given quercetin. Suggesting thatquercetin can protect the periodontal tissue. |
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