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

ABSTRACT 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.