| Background:Chronic periodontitis is a chronic inflammatory disease caused by the activation of host specific pathogenic bacteria.It is often manifested as gingivitis,periodontal pocket formation,periodontal abscess,tooth loosening,tooth displacement and so on.The prevalence of periodontitis in China is up to 80%-90%,which is the main cause of tooth loss in adults.In patients with chronic periodontitis can detect many inflammatory markers,such as inflammation factors(interleukin-6,interleukin-1)and biomarkers of bone remodeling(alkaline phosphatase,type I collagen peptide),molecular destruction of connective tissue(matrix metalloproteinases)etc.The study found that the matrix metalloproteinase(MMPs)released by inflammatory cells may be one of the causes of periodontal tissue damage,and the level of MMPs is closely related to the progress of chronic periodontitis.As one of the family members of MMPs,matrix metalloproteinase 7(MMP-7)has a strong matrix degradation activity.It can degrade most of the extracellular matrix,such as I,II type collagen and laminin.Mucin is a high molecular weight glycosylated protein,which plays an important role in protecting mucosal epithelium and cell signal transduction.Mucin 4(MUC-4)is a multifunctional protein,which plays an important role in cell movement,adhesion,signal transduction and so on.The study of MMP-7 in periodontitis is mostly before periodontal treatment,but there is less study on the changes of MMP-7 levels before and after periodontal treatment.Most of the studies on MUC-4 are in the type and mechanism of tumor.There are few studies on chronic periodontitis in foreign countries,and there are no reports in China at present.Therefore,we compared the levels of MMP-7 and MUC-4 in serum and gingival crevicular fluid(GCF)of chronic periodontitis patients and healthy persons,and the levels of MMP-7 and MUC-4before and after periodontal treatment in patients with chronic periodontitis.To investigate the relationship between chronic periodontitis and MMP-7 and MUC-4,and the effect of periodontal therapy on the level of MMP-7 and MUC-4in gingival crevicular fluid.In order to verify that MMP-7and MUC-4 are new biomarkers of periodontitis,the level of matrix metalloproteinase 9(MMP-9)has been detected in this experiment,because it has been reported many times in periodontitis,which is significantly higher than that in healthy group.Method:1.Experimental grouping All cases were from the periodontist of the Jilin University stomatology hospital from January 2017 to December2017.31 patients with chronic periodontitis and 23 healthy persons were selected.2.Detection index All subjects were collected for clinical data,including age,sex,smoking history,past history,and so on.Before the periodontal treatment,all the subjects were routinely collected with fasting venous blood,and the supernatant was frozen and preserved after the blood centrifugation.1 molars in the same quadrant were selected as the study teeth,and one doctor collected GCF to cryopreservation before and after 4weeks of treatment.The periodontal clinical indexes were recorded at 6 ortho-surface sites of the selected teeth.3.MUC-4 and MMP-7 analysis The levels of MMP-7,MUC-4 and MMP-9 in serum and GCF of the subjects were detected by ELISA.SPSSl9.0 software was used to make statistical analysis of the experimental data.Result:1.The general data of the control group and the chronic periodontitis group were compared(P>O.05),and the difference was not statistically significant.Compared with the control group and the chronic periodontitis group,the difference in periodontal clinical index was statistically significant(P<O.01).2.In chronic periodontitis group,the levels of MMP-7 and MMP-9 in serum and GCF before treatment were higher than those in control group(P<O.05),while MUC-4 level was lower than that in control group(P<O.05),the difference was statistically significant.3.The level of MMP-7 in GCF samples was positively correlated with clinical index plaque index(PLI)(P<0.05),and positively correlated with probing depth(PD),attenchment loss(AL),bleeding index(BI)and GCF(P<0.01).The level of MUC-4 in samples is negatively correlated with AL and BI(P<0.05).The level of MMP-9 in samples was positively correlated with AL(P<0.05),and positively correlated with PD and GCF(P<0.01).4.The clinical indicators PLI,PD,BI and GCF after periodontal treatment in chronic periodontitis group were significantly lower than those before treatment(P<0.01),the difference was statistically significant.5.After periodontal treatment,the levels of MMP-7 and MMP-9in GCF in chronic periodontitis group were lower than those before treatment(P<O.01),while the level of MUC-4 increased(P<O.05),the difference was statistically significant.Conclusion:1.The level of MMP-7 and MMP-9 is positively correlated with periodontitis inflammation in patients with chronic periodontitis.MUC-4 level is negatively correlated with inflammation degree of periodontitis.MMP-7 and MUC-4 can be used as biological indicators for detecting chronic periodontitis.2.Periodental non-surgical treatment can significantly improve the periodontal clinical index(PLI、PD、BI、GCF)and the levels of MMP-7,MUC-4 and MMP-9 in GCF of patients with chronic periodontitis.3.The level of MMP-7 and MUC-4 in GCF changed significantly before and after periodontal treatment.It can objectively evaluate the therapeutic effect of chronic periodontitis,and provide a reference for the progression and prognosis of chronic periodontitis.4.MMP-9 is an objective indicator for the diagnosis of periodontitis,and can provide reference for the detection of the expression of MMP-7 and MUC-4 in chronic periodontitis. |
