Diagnosis of periodontitis by physical measurement: interpretation from episodic disease hypothesis.

Physical measurements including the evaluation of probing depth, bleeding on probing, tooth mobility, and inflammation form the basis for most periodontal diagnostics in use today. The interpretation of these observations and the methods available for their measurement, however, have begun to change significantly. The episodic disease activity concept has done much to implement these changes. Observation of episodic attachment loss has been correlated with parallel radiographic changes, alteration in levels of probable pathogens, and changes in inflammatory mediator levels. The failure of pocket depth, suppuration, and bleeding on probing to predict episodic attachment loss has been given plausible explanations and enhanced meanings. Although attachment loss by a continuous process cannot be excluded in some disease conditions, the hypothesis of periodontal disease progression by episodic activity supplements and expands understanding of the disease process. Interest in periodontal diagnostics has accelerated in the last decade. As a parallel development, the technology of small computers has decreased in cost and increased in sophistication. The combination of these factors has created an environment for the development of intelligent diagnostic systems. Four commercially available systems and two systems under development are described. The systems, which measure pocket depth, pocket depth or attachment level, tooth mobility, and pocket temperature, all utilize computer processing of measurements. The result is to provide a simplified and more meaningful presentation of diagnostic information. As intelligent diagnostic systems prove themselves, some of these instruments are likely to become common to dental practice. The promise of more accurate identification of areas of the mouth that are diseased can increase both the efficiency and effectiveness of periodontal therapy.