The document discusses antibiotic adjunct therapies used in periodontal treatment. It provides an overview of various antibiotics commonly used including penicillin, macrolides, tetracyclines, metronidazole, ciprofloxacin and clindamycin. It describes their mechanisms of action, effectiveness against specific pathogens, clinical applications and considerations for use. The document also discusses local drug delivery systems like Actisite, Arestin and their advantages over systemic administration in treating periodontal diseases.