A perspective on periodontal disease activity measurements.

Studies utilizing serial standardized periapical radiographs for measurements of alveolar bone height and for digital subtraction and changes in clinical probing attachment level have suggested that adult periodontitis may exhibit periods of exacerbation and remission at specific sites. The use of such serial examinations for the determination of disease activity must be interpreted with caution since the different methods for the assessment of disease activity have different levels of sensitivity and specificity and because such sequential methods integrate disease activity and do not provide an instantaneous measure of activity. An ideal test for disease activity would approach an instantaneous measure of disease activity and would not integrate activity over time.