Biologically active factors in the treatment of periodontal disease.

Cells in normal tissue progress through programs of growth, differentiation, and death. Many of the signals that start and stop this process are initiated by growth factors produced by other cells or by the resident cells. This network of intercellular signaling represents the basis for establishing and maintaining normal tissue architecture. Growth factors are released by some cells and conveyed to target cells, where they are bound to specific receptors, triggering a complex signal transduction cascade. Human periodontal ligament cells have been shown by in vitro assays to respond both mitogenically and chemotactically to a variety of growth factors including, but not limited to, platelet-derived growth factor, basic fibroblast growth factor, and transforming growth factor-beta. Evidence is presented for confirmation of an autocrine chemotactic and mitogenic human periodontal ligament cell-specific factor. This type of knowledge suggests that future periodontal regeneration procedures will rely on the exogenous addition of specific growth factors.