Bone cell interactions and regulation by inflammatory mediators.

The loss of alveolar bone tissue associated with periodontal disease appears to be related to local factors that alter the physiologic balance between bone formation and resorption. Physiologic bone metabolism requires the coupled activities of bone resorption and bone formation. Recent investigations of this coupling phenomenon have been directed at understanding the regulatory mechanisms involved in osteoblast-osteoclast interactions. These regulatory mechanisms utilize multiple cytokines, which function in context with numerous other factors, including cell-cell interactions, extracellular matrix molecules, and levels of differentiation. Local alterations of these factors may disrupt the physiologic balance in bone metabolism and lead to the pathologic loss of alveolar bone. Future strategies for altering bone loss found in the periodontal diseases will be directed at modulating the balance of bone resorption and bone formation at the local site.