The Change Of Carboxyterminal Propeptide Of Type â…  Procollagen In Gingival Crevicular Fluid Of Periodontitis Before And After Periodontal Initial Therapy

Objectives: Type I collagen are widely distributed in the periodontal tissue. Under normal circumstances, the metabolism of type I collagen in periodontal tissue is a continuous, dynamic process, which keeps in a balance between the synthesis of the new collagen and the decomposition of the old collagen. Once this balance is broken, it can lead to diseases. Carboxyterminal propeptide of type I procollagen(PICP), produced in the process of type I collagen synthesis, can accurately reflect the synthesis rate of type I collagen because of the ratio of 1:1 with the type I collagen. The purpose of this study is to compare the concentration of PICP in gingival crevicular fluid (GCF) of chronic periodontitis before and after periodontal initial therapy by Enzyme-linked immunosorbent assay (ELISA), analyze PICP levels before and after periodontal initial therapy and the relationship between PICP and clinical parameters, explore whether PICP could be an objective indicator for monitoring the effects of periodontal initial therapy.Methods:1 Eighteen chronic periodontitis were enrolled in the study, including eight males and ten females (age from 42 to 58, average 49.8). The tooth , probing depth≥3mm, attachment loss≥1mm ,different degrees of absorption of alveolar bone in X-ray and without cavity and filling on the cervix was selected as the observed tooth and totally thirty-two teeth were chosen.2 Plaque control, supragingival scaling,?subgingival scaling, occlusal therapy, stabilization of loosen teeth and dental treatment were included in the periodontal initial therapy.3 Clinical parameters including gingival index (GI), probing depth (PD), attachment loss (AL)were examined and recorded before periodontal initial therapy (base line) ,two weeks, four weeks, six weeks, eight weeks and twelve weeks after the periodontal initial therapy respectively.4 The GCF samples were collected using Whatman 3# filter paper strips. It was inserted into the buccal periodontal pockets of the observed teeth, then removed after 30 seconds. After 1 minute GCF samples were collected at the same site and in the same way again. The samples were sealed and preserved in - 20℃for inspection. The samples were collected before periodontal initial therapy (base line), two weeks, four weeks, six weeks, eight weeks and twelve weeks after initial therapy respectively.5 PICP levels in GCF were quantified using ELISA.Results:1 The clinical parameters reduced after initial therapy, the differences were statistically significant.2 The PICP concentration in GCF of chronic periodontitis was 4.10±1.86mg/l before periodontal initial therapy, 20.26±3.55mg/l two weeks after periodontal initial therapy, 6.79±1.73mg/l four weeks after periodontal initial therapy, 5.31±1.26mg/l six weeks after periodontal initial therapy, 4.05±0.95mg/l eight weeks after periodontal initial therapy, 4.95±0.57mg/l twelve weeks after periodontal initial therapy. The statistical analysis showed that the concentration of PICP those of two weeks and four weeks after periodontal initial therapy were significantly higher than the base line (P<0.05). And there was no significant difference among other groups.3 There were negative significant correlations between the PICP concentration in GCF and PD or AL, and there was no correlation between the PICP concentration in GCF and GI.Conclusions:1 The clinical parameters reduced after initial therapy, which indicated that the initial therapy was an effective way to treat periodontal disease through improving the status of periodontal tissue inflammation.2 The PICP concentration in GCF of chronic periodontitis significantly increased two weeks after initial therapy and reached the peak. Then it gradually decreased to the base line at six weeks after initial therapy. The PICP concentration in GCF of chronic periodontitis could reflect the metabolic status of periodontal tissues, suggesting that it could be a biochemical indicator for evaluating the therapeutic effect in the early period after initial therapy.3 There were negative correlations between the PICP concentration in GCF and PD or AL, but values of r~2 were low. And there was no correlation between the PICP concentration in GCF and GI.