Inclusion Criteria:  Patients diagnosed with periodontitis; Age ≥ 18 years old; Presence of at least 10 teeth per arch; Presence of at least two teeth with Probing Depth (PD) ≥ 5 mm per quadrant; Presence of at least one intraosseous pocket; Single-rooted and multi-rooted teeth.  Exclusion Criteria:  Patients with systemic diseases; Prolonged antibiotic or anti-inflammatory treatment within 4 weeks prior to periodontal therapy; Pregnant or lactating; Tobacco smokers (≥ 10 cigarettes per day); Multi-rooted teeth with furcation involvement; Third molars.