[The influence of two kinds of crown margin designs on MMP-8 and TIMP-1 levels in gingival crevicular fluid ].

AIM: To explore the influence of two kinds of crown margin designs on MMP-8 and TIMP-1 levels in gingival crevicular fluid(GCF). METHODS: 16 cases of patients who needed full crowns were divided randomly into two groups: subgingival group and gingival crest group. The GCF were taken before tooth preparation, one month, three months and six months after crown placement. The levels of MMP-8 and TIMP-1 in GCF were determined by ELISA. RESULTS: The levels of MMP-8 and TIMP-1 in GCF before tooth preparation made as baseline. The level of MMP-8 at one month after crown placement in subgingival group was higher than the baseline ( P <0. 05) and contiue increasing at three months after crown placement. The level of MMP-8 at six months after crown placement in subgingival group decreased, but it was higher than the baseline(P<0.05). In gingival crest group, atfer inserting crowns, the levels of MMP-8 and TIMP-1 was no signifieantly change. In two gourps, atfer inserting crowns, the levels of MMP-8 and TIMP-1 signifieantly increased. The level of MMP-8 in subgingival group was higher than that in gingival crest group at all times and the level of TIMP-1 in subgingival group was lower than that in gingival crest group. CONCLUSION: Gingival crest crown margin design is more fvourable to the effect of MMP-8 and TIMP-1 in maintaining the health and the regular remodeling of the periodontium.