Tooth loss in generalized aggressive periodontitis: Prognostic factors after 17 years of supportive periodontal treatment

Aim: This retrospective longitudinal study assessed the risk of and prognostic factors for tooth loss in patients with generalized aggressive periodontitis (GAgP) after periodontal treatment in a university setting. Methods: Fifty-seven patients (1,505 teeth) were examined before (T0) and after active periodontal therapy (APT, T1) as well as after 17.4 +/- 4.8 [range: 9-28] years of supportive periodontal therapy (SPT, T2). Descriptive statistics and a Cox-proportional-hazards shared-frailty model were applied. Results: Overall, 98 and 134 teeth were lost during APT and SPT, respectively, with 0.14 +/- 0.18 teeth being lost per patient and year. During SPT, three patients (5%) lost >= 10 teeth, 14 (25%) lost 4-9 teeth, 40 lost 0-3 (70%) teeth, respectively. One-third (n = 19) of all patients lost no teeth. Mean PPD of the teeth surviving SPT was stable from T1 (3.5 +/- 1.1 mm) to T2 (3.4 +/- 1.1 mm). Nearly, 84% of all survived teeth showed stable or improved bone level at T2. Risk of tooth loss was significantly increased in active smokers (HR[95% CI]: 4.94[1.91/12.75]), the upper dental arch (1.94[1,16/3.25]), with each mm of residual PPD (1.41[1.29/1.53]), teeth with furcation involvement (FI) (HR 4.00-4.44 for different degrees) and mobility (5.39 [2.06/14.1] for degree III). Conclusion: Within the provided conservative treatment regimen, GAgP patients lost only few teeth.