Efficacy of CPITN sextant scores for detection of periodontitis disease activity.

The relationship between CPITN sextant scores and periodontitis recurrence at individual tooth sites was evaluated in a longitudinal study in 83 treated adult periodontitis patients receiving systematic 3-month maintenance care. At baseline and semi-annual examinations over 36 months, CPITN scores were assigned to each dentition sextant using probing depths and gingival index scores, and relative periodontal attachment level was assessed at individual tooth sites using an occlusal reference stent. Periodontitis recurrence was defined as any periodontal site exhibiting either a probing depth increase of > or = 3 mm from baseline, or a probing depth increase of > or = 1 mm from baseline together with a loss of relative periodontal attachment of > or = 2 mm from baseline. 49 (59.0%) subjects developed periodontitis recurrence in 147 (29.8%) sextants at 181 (2.2%) individual periodontal sites during the 36-month study period. Baseline CPITN scores of 4 were more common in disease-active subjects than clinically-stable subjects (p = 0.003, t-test), and were associated with a statistically significant 1.66 relative risk of periodontitis recurrence within 36 months. CPITN sextant scores of 3 or 4 showed low specificity and low positive predictive values as indicators of periodontitis recurrence at > or = 1 individual sites within the affected sextant. In comparison, low CPITN sextant scores (0-2) provided high specificity (96.2-100%), high positive predictive values (99.5-100%), and a summary odds ratio of 24.2 as an indicator of clinical stability at all periodontal sites within a given dentition sextant. Changes in sextant scores for CPITN over 6-month periods showed no relationship with periodontitis recurrence at individual periodontal sites. This study suggests that while CPITN is inadequate for detection of periodontitis recurrence, low CPITN scores provide rapid presumptive identification of clinically-stable sextants in adult periodontitis patients on maintenance care.