Periodontal disease activity.

Periodontal disease activity is defined clinically by progressive loss of probing attachment and radiographically by progressive loss of alveolar bone. The natural history of periodontal disease was originally considered to be nearly continuous and slowly progressive. Clinical research conducted in the last decade suggests that periodontal disease demonstrates periods of exacerbation and remission. Using sensitive automated probes, studies published during the past year have demonstrated that different patterns of disease activity can exist, and that these patterns may be dependent on the disease threshold. Subtraction radiography continues to be refined, but cost and methodology prevent this diagnostic tool from having widespread clinical application. A variety of clinical, microbiologic, and host-response parameters have been studied for their relationship to periodontal disease activity. Many research groups are attempting to develop a diagnostic test that identifies the risk for development of active disease. A relatively simple test based on the presence of a microbial virulence factor, or the host inflammatory or immune response to the subgingival microflora, may be a practical means for clinicians to detect the active phases of periodontal disease.