Tooth loss in compliant and non-compliant periodontally treated patients: 7 years after active periodontal therapy

Abstract
To investigate the incidence and reasons for tooth loss during active periodontal therapy (APT) and periodontal maintenance (PM) in a specialist institution. Retrospective data were collected from 273 patients [all compliers (AC)] and cross-sectional data from 39 patients after discontinuation of PM [non-compliers (NC)] for at least 7 years after APT. Descriptive statistics and regression analysis were performed. A comparison was made between AC and NC. The prognostic factors associated with tooth loss during PM were identified. AC lost 1.3 teeth/patient during APT and 0.9 teeth/patient during PM (mean 10.7 years). Tooth loss due to periodontitis was 0.03 teeth/patient/year. The age of 60 was a significant predictor of tooth loss during PM (odds ratio of 2.1). NC lost 1.1 teeth/patient during APT and 2.7 teeth/patient during discontinuation (mean 9.6 years). Tooth loss due to periodontitis was 0.22 teeth/patient/year, a sevenfold increase (p<0.05) compared with AC. Regression analysis failed to identify any significant predictors for tooth loss during the discontinuation of PM. In this study, the provision of PM led to minimal tooth loss, especially due to periodontitis, for a mean period of 10 years after APT. The completion of APT without PM may predispose patients to lose more teeth compared with patients who undergo PM.