The Effectiveness of Metronidazole as a Localized Drug Delivery System in the Treatment of Periodontal Diseases: A Narrative Review

Periodontitis is a complex, multifactorial chronic inflammatory condition that impacts the adjacent hard and soft tissues. Microorganisms, especially gram-negative anaerobic pathogens, are a causative factor for periodontal disease. Periodontitis is identified by observing deeper periodontal pockets, clinical attachment loss, and the reduction of alveolar bone, often in conjunction with these indicators. The condition can vary in severity and be classified as mild, moderate, or severe. Scaling and root planing, combined with mechanical debridement, may not adequately reduce the bacterial load; therefore, adding local or systemic antimicrobials is advised as an adjunctive treatment. Commonly utilized local drug delivery agents for patients suffering from periodontitis include tetracycline, metronidazole, minocycline, doxycycline, and chlorhexidine. This system targets the pockets and eliminates the pathogens. Metronidazole is a nitroimidazole compound used commonly against gram-negative anaerobes. Its mechanism lies in four basic steps through which bacterial cell death occurs. A 25% metronidazole gel is used widely in periodontitis patients. The effectiveness of metronidazole as a local drug delivery agent has been evaluated in numerous studies, which have shown improvements in clinical parameters. To achieve favorable clinical outcomes, the non-surgical treatment of peri-implantitis should involve the systemic or local administration of metronidazole. Thus, the role of metronidazole in the emergence of periodontal diseases and its therapeutic uses are investigated in this narrative review.