Evaluation of Antibacterial Efficacy of Zinc Oxide Nanoparticles, Garlic Extract, and Their Combination versus Sodium Hypochlorite as Endodontic Irrigants Against Enterococcus faecalis in Single Rooted Teeth (A Comparative In Vitro Study) v1

Endodontic infections pose significant challenges in clinical practice due to their complex microbiology and the resilient nature of the causative organisms. These infections often lead to persistent apical periodontitis, which remains a major cause of root canal treatment failure. Effective cleaning and disinfection of the root canal system are critical for the success of endodontic treatment. Despite the structural complexities of the internal root anatomy, root canal irrigants are vital in enhancing the chemo-mechanical process of root canal preparation. Enterococcus faecalis, a Gram-positive facultative anaerobic coccus, is the predominant Enterococcus species identified in refractory lesions and is associated with up to 77% of treatment failures. E. faecalis possesses a unique ability to invade dentinal tubules, demonstrates strong adhesion to collagen, and often persists within the root canal system even after instrumentation and irrigation. Sodium hypochlorite (NaOCl) has long been considered the gold standard irrigant in endodontics due to its potent antibacterial properties and tissue-dissolving capabilities. However, its cytotoxic effects on periapical tissues and potential to cause chemical burns and unpleasant taste have prompted the search for safer alternatives. Nanotechnology offers a promising avenue in the development of advanced antimicrobial agents. Zinc oxide nanoparticles (ZnO Nps), characterized by their high surface area and ability to generate reactive oxygen species, exhibit significant antibacterial activity against a wide range of microorganisms, including E. faecalis. Natural products, such as garlic (Allium sativum), have also garnered attention as potential alternatives to conventional irrigants. The synergistic combination of ZnO nanoparticles and garlic extract could provide enhanced antimicrobial efficacy while mitigating the drawbacks associated with traditional irrigants. By leveraging the complementary mechanisms of these agents, this study aims to evaluate their effectiveness against E. faecalis in comparison to NaOCl. The findings could pave the way for safer, more effective irrigation protocols in endodontics.