No abstract

The results show that the gingival microcirculation recovers to normal in the early stages of smoking cessation, which could activate the gingival tissues metabolism/remodeling, and contribute to periodontal health.

Upregulated MMP expression and an increased MMP/TIMP ratio indicate that a potential imbalance between degradation and synthesis of extracellular matrix persists in periodontitis-affected gingival tissues. This process may be responsible for increased tissue breakdown in periodontitis.

Our data did not support the hypothesis that MMP-1 and/or MMP-3 gene promoter polymorphisms influenced the susceptibility to periodontitis in Japanese patients, indicating MMP-1 and MMP-3 expressions were regulated by complex processes such as cytokine network in periodontal disease rather than gene polymorphisms.

The mechanism of enamel matrix derivative (EM D) action on the periodontal wound healing process is not well understood. However, earlier in vitro studies from our laboratory demonstrated that EMD stimulated the proliferation of both periodontal ligament and gingival fibroblast cells. Therefore, the purpose of this study was to further evaluate the effect of EMD on the early wound healing process by assessing the protein levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in gingival crevicular fluid (GCF). Sixteen patients, each of whom had one or two pairs of infrabony defects located contralaterally in the same arch, were included in this clinical trial. Thirty-six infrabony defects were randomly assigned treatment with flap surgery plus EMD or flap surgery plus placebo. At baseline and at 2, 4 and 12 week follow-up evaluation visits, GCF was sampled with paper strips. After determination of GCF volume, TIMP-1, MMP-1 and MMP-8 GCF levels were measured by an enzyme-linked immunosorbent assay. Intragroup analysis: At week 2 following surgery, when compared to baseline all parameters in each study group, except MMP-1, significantly increased (p<0.05). There were no significant differences between 4 or 12 weeks and baseline in either study group. Intergroup analysis: At 4 weeks after surgery, GCF volume and TIMP-1 levels showed a significant decrease (p<0.05) in the EMD group, when compared to the placebo group. MMP-1 levels at weeks 2, 4 and 12, and MMP-8 levels at weeks 4 and 12 were significantly lower (p < 0.05) in the EMD group compared to the placebo group. EMD compared to placebo treated sites demonstrated a more rapid return to baseline levels of TIMP-1, MMP-1 and MMP-8. These findings suggest that treatment with flap surgery and EMD, compared to flap surgery with placebo, accelerated healing at an earlier stage of wound healing following surgery.