The role of cytokines in the pathogenesis of periodontal disease.

Recent advances in cellular and molecular biology have allowed investigators to better understand the mechanisms of inflammatory and immune responses in many infectious diseases. Soluble mediators produced by various inflammatory and structural cells, collectively called cytokines, have been shown to play a crucial role in the pathogenesis of most of these diseases, including periodontal disease. This paper globally reviews recently reported findings implicating cytokines in periodontal pathophysiology. Inflammatory mediators, such as interleukin-1, tumor necrosis factor-alpha, and interferon-gamma, known to regulate bone resorptive activity are present in diseased periodontal tissues. Similarly, metalloproteinases, which degrade extracellular matrix, have been shown to have increased activity in diseased sites, and enhanced levels of their inhibitors correlate with absence of disease activity. Finally, certain polypeptide growth factors originally known to play a role in wound healing are now shown to have a significant effect in inflammatory responses.