This study is designed as a parallel, masked, randomized, placebo-controlled clinical trial to assess the clinical, microbiological, and immunological outcomes of scaling and root planning (SRP) or full-mouth ultrasonic debridement (FMUD) with AM (Amoxicillin + Metronidazole) for the treatment of Generalized Aggressive Periodontitis (GAgP).

Forty eight GAgP patients were divided into 4 groups: the SRP group (n = 12), which received SRP plus placebo, and the SRP+AM group (n = 12), which received SRP and 375mg amoxicillin plus 250 mg metronidazole for 7 days, the FMUD group (n = 12), which received FMUD plus placebo, and the FMUD+AM group (n = 12), which received FMUD and 375mg amoxicillin plus 250 mg metronidazole for 7 days. The following clinical outcomes were tested: plaque and bleeding on probing indices, pocket probing depth (PD), relative gingival margin position (GMP), and relative clinical attachment level (CAL). The total amount of Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Tannerella forsythia (Tf), and gingival crevicular fluid (GCF) concentration of interleukin (IL)-10 and IL-1b were also determined. All clinical, microbiological, and immunological parameters were assessed at baseline and at 3 and 6 months post-therapy. The ANOVA/Tukey test was used for statistical analysis (a = 5%).

Inclusion Criteria:

• diagnosis of GAgP;
• presence of 20 teeth;
• presence of teeth presenting PD>5 mm with bleeding on probing (BOP) and 2 teeth with PD>7mm (including incisors and first molars, in addition to two other non-contiguous teeth between them);
• good general health;
• <35 years of age.

Exclusion Criteria:

• were pregnant or lactating;
• were suffering from any other systemic diseases (e.g., cardiovascular, diabetes);
• received antimicrobials in the previous 3 months;
• were taking long-term anti-inflammatory drugs;
• received a course of periodontal treatment within the last 6 months;
• smoked