The Periodontal Disease Index (PDI)

THE PERIODONTAL Disease Index is a clinician's modification of Russell's PI index for epidemiological surveys of periodontal disease. The PDI index is primarily concerned with an accurate assessment of the periodontal status of the individual person. Emphasis is placed on recording of the attachment level of the periodontal tissues relative to the C-E junction. Such accurate measurable assessments are essential for longitudinal studies of periodontal disease and as a scientific basis for clinical trials in Periodontology.