A patient has aggressive (Grade C) periodontitis: generalized 4-5 mm pockets, bone loss and calculus on posterior teeth, and heavy calculus on anterior teeth. What is the most appropriate FIRST treatment approach?

Correct answer: C. Scaling and root planing PLUS systemic amoxicillin + metronidazole

• A. A coronal-only prophylaxis does not remove SUBgingival biofilm/calculus; antibiotics without thorough mechanical debridement are inadequate.
• B. For aggressive periodontitis, SRP alone is often insufficient — adjunctive systemic antibiotics improve outcomes (unlike in routine chronic periodontitis).
• C. Correct. Aggressive/Grade C periodontitis (often Aggregatibacter actinomycetemcomitans-associated) responds best to mechanical debridement (SRP) combined with ADJUNCTIVE systemic amoxicillin + metronidazole (the van Winkelhoff cocktail), which targets the invasive pathogens that scaling alone cannot fully reach.
• D. Surgery is not the FIRST step; nonsurgical therapy (SRP +/- antibiotics) comes first, with surgery reserved for residual disease.