Modified periodontal risk assessment score: long-term predictive value of treatment outcomes. A retrospective study.

The aim of this study was to evaluate the long-term clinical predictive value of the periodontal risk assessment diagram surface (PRAS) score and the influence of patient compliance on the treatment outcomes. Thirty subjects suffering from periodontitis were re-examined 6-12 years after the initial diagnosis and periodontal treatments. The baseline PRAS score was calculated from the initial clinical and radiograph records. Patients were then classified into a low-to-moderate (0-20) or a high-risk group (>20). Patients who did not attend any supportive periodontal therapy were classified into a non-compliant group. PRAS and compliance were correlated to the mean tooth loss (TL)/year and the mean variation in the number of periodontal pockets with a probing depth (PPD) >4 mm. TL was 0.11 for the low-to-moderate-risk group and 0.26 for the high-risk group (p<0.05); PPD number reduction was 2.57 and 2.17, respectively, and bleeding on probing reduction was 6.7% and 23.3%, respectively. Comparing the compliance groups, the PPD number reduction was 3.39 in the compliant group and 1.40 in the non-compliant group (p<0.05). This study showed the reliability of PRAS in evaluating long-term TL and patient susceptibility to periodontal disease. Our data confirmed the positive influence of patient compliance on periodontal treatment outcomes.