Which treatment is most appropriate for the necrotizing periodontal condition above?

Correct answer: B. Metronidazole

• A. Amoxicillin is not first-line for necrotizing disease; the predominant flora is anaerobic/spirochetal.
• B. Correct. Metronidazole targets the anaerobic organisms (fusiform bacteria, spirochetes) driving necrotizing periodontal disease, alongside debridement and improved hygiene.
• C. Chlorhexidine helps as an adjunct but alone is insufficient for systemic involvement/necrosis.
• D. Active necrosis with tissue destruction requires treatment — doing nothing is inappropriate.