Methods: 88 patients were re-examined on average 10.5 years after initial treatment. Re-examination by one investigator consisted of patient's history, detailed questionnaire on smoking habits, clinical examination and test for IL-1 polymorphism. Patients' charts were searched for regularity of maintenance and initial radiographic records. Using the modified PRA both including and excluding Interleukin-1-polymorphism (IL-1), each patient was retrospectively assigned to either the low /moderate or high risk profile. Statistical analysis was performed by multivariate regression analysis using the parametric Weibull model for interval censored data and the Cox proportional hazards model with compliance as time dependent covariate. (SAS version 9.2 for Windows, SAS Institute Inc., Cary, NC)
Results: Modified PRA excluding IL-1 showed a statistically significant impact on tooth loss (p=0.003) and bone loss (p=0.08) during SPT: Individuals with a high risk profile were 2.74 times more likely to experience tooth loss and 3 times more likely to display bone loss. No statistically significant difference could be documented concerning recurrence of periodontitis. Patients complying with recommended maintenance intervals lost fewer teeth than others (HR=2.0, p=0.06) and none of them showed recurrence of disease.
Conclusion: This study verified the reliability of PRA (excluding IL-1) in patients with aggressive periodontitis for the first time. Both tooth and bone loss was significantly enhanced. Secondly, the positive influence of patient compliance on periodontal treatment outcomes was confirmed.
This study was supported by Hain Life Science GmbH (Nehren, Germany)