Host modulation for the treatment of periodontal disease.

Until the 1970s, treatment strategies for periodontal diseases were primarily based on the understanding that plaque bacteria and their products mediated the tissue destruction in periodontal patients. This concept began to change, however, when investigators reported that host responses to the causative bacteria were a major contributor to disease pathogenesis. With a new understanding of host response and periodontal disease pathogenesis, it became apparent that inhibition of certain host response pathways might be an additional strategy, in addition to suppressing the causative bacteria, for treating periodontal diseases. The current understanding of periodontal disease etiology and pathogenesis emphasizes the role of the host in tissue destruction (Figure1).