Outcomes of Active Periodontal Therapy in a Specialist University Setting Following EFP S3 Treatment Guideline in Stage III–IV Periodontitis Patients

Aim: To describe the efficacy of steps I–II–III of periodontal therapy performed in a specialist university setting following EFP S3 treatment guideline and to assess factors associated with the achievement of endpoints of therapy (EoT). Methods: Records of 131 stage III–IV periodontitis patients were collected retrospectively. Residual pockets (probing pocket depth [PPD] 5 mm with bleeding on probing [BoP] or PPD ≥ 6 mm) after steps I–II (T1) received repeated subgingival instrumentation (RSI) or surgery and were re-evaluated after 1 year (T2). EoT (no PPD ≥ 5 mm BoP+ and no PPD ≥ 6 mm) rate at T1 and T2 was computed, and predictors explored through multilevel analyses. Results: At T1, EoT was 67.8%, with step III yielding an additional 90.0% of EoT in PPD = 5 mm BoP+ and 85.3% in PPD ≥ 6 mm. Factors negatively associated with EoT were: posterior teeth, furcation involvement (degree II–III), initial PPD, interproximal location and plaque. When considering only pockets ≥ 6 mm, factors were PPD at T1, type of intervention (resective surgery over RSI) and plaque at T2. Overall, 55.7% of patients reached EoT, 16.1% achieved ‘stable periodontitis’ (PPD ≤ 4 mm, no PPD = 4 mm BoP+, BoP < 10%). Conclusions: Guideline-based periodontal therapy achieved EoT targets in 93.3% of sites and 50% of patients with Stage III–IV periodontitis.