Comparative evaluation of chlorhexidine and antibiotic combination irrigants containing amoxyclav, ciprofloxacin and metronidazole for root canal disinfection An in vivo study

Root canal infections are polymicrobial in nature and are a major cause of failure of endodontic treatment. Mechanical instrumentation alone is insufficient to completely eliminate microorganisms from the complex root canal anatomy, necessitating the use of effective irrigating solutions. Chlorhexidine is a commonly used irrigant due to its broad-spectrum antimicrobial activity and substantivity; however, it lacks tissue-dissolving properties and may be less effective against resistant microorganisms. Antibiotic combinations such as amoxyclav, ciprofloxacin, and metronidazole offer broader antimicrobial coverage and may enhance root canal disinfection.This randomized controlled clinical trial aims to comparatively evaluate the antimicrobial efficacy of 2% chlorhexidine, 2% chlorhexidine with metronidazole (0.5%), amoxyclav (1.2 g) with metronidazole (0.5%), and ciprofloxacin (0.2%) with metronidazole (0.5%) as root canal irrigants. A total of 60 patients requiring primary root canal treatment in single-rooted permanent teeth diagnosed with pulp necrosis and/or chronic apical periodontitis will be recruited and randomly allocated into four groups. All cases will undergo standardized chemomechanical preparation using 5.25% sodium hypochlorite and 17% EDTA, followed by final irrigation with the assigned study solution.Microbiological samples will be collected before and after irrigation using sterile paper points, and intracanal bacterial load will be assessed by culture techniques and expressed as colony-forming units per milliliter (CFU/ml). The primary outcome measure will be the reduction in intracanal microbial load, while secondary outcomes will include intergroup comparison of antimicrobial efficacy, percentage reduction in bacterial counts, reduction in Enterococcus faecalis, and incidence of adverse events. The results of this study may help identify a more effective irrigation regimen for enhanced root canal disinfection.