Objectives: We aimed to assess how the 2018 and 1999 classifications of periodontal diseases reflect (a) patients' characteristics, (b) disease severity/extent/progression and (c) tooth loss (TL) during observation period.
Methods: A total of 251 patients were followed over 21.8 ± 6.2 years. For the 1999 classification, using clinical attachment level (CAL), patients were classified as localized/generalized, mild/moderate/severe and aggressive/chronic periodontitis. For the 2018 classification, patients were staged according to their CAL or bone loss (BL) and the number of lost teeth (stages I-IV). Further factors like probing pocket depths (PPD) or furcation involvement modified the stage. The extent was sub-classified as generalized/localized. Patients were graded according to the BL/age index, smoking and/or diabetes.
Results: According to the 1999 classification, most patients suffered from generalized severe chronic periodontitis (203/251) or generalized aggressive periodontitis (45/251). Patients with aggressive periodontitis were younger and less often female or smokers. They showed similar TL (0.25 ± 0.22 teeth/patient*year) as generalized severe chronic periodontitis patients (0.23 ± 0.25 teeth/patient*year). According to the 2018 classification, most patients were classified as generalized III-C (140/251), III-B (31/251) or IV-C (64/251). Patients' age, smoking status, CAL, PPD and BL were well reflected. TL differed between IV-C (0.36 ± 0.47), generalized III-C (0.21 ± 0.24) and localized forms (0.10-0.15).
Conclusions: Patients' characteristics, disease severity/extent/progression and TL were well reflected by the 2018 classification.
Keywords: periodontal diagnostic; periodontal therapy; periodontitis; tooth loss; treatment planning.
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