Antimicrobial Efficacy of a Novel Irrigant, Nigella–Eugenia Oil Composite against Enterococcus faecalis and Candida albicans

neutralize necrotic tissues and completely remove pulpal remnants and predentin on the instrumented surfaces. 12Although it confers many advantageous properties, at higher concentrations it causes ulceration, hemolysis, and necrosis outside the confines of root canals and may injure periapical tissues. 13Other known disadvantages include unpleasant taste, tendency to bleach clothes and, inability to remove the smear layer. 14Furthermore, there are some debates about its antibacterial activity at lower concentrations, which are promoted as a way to reduce harmful reactions. 15hlorhexidine (CHX) gluconate, a cationic bisbiguanide, is often suggested as an irrigant in endodontics for its antibacterial effects and substantivity, which permits it to reside attached to different IntroductIonThe main goal of endodontic treatment is elimination of microorganisms and their byproducts from the root canal system. 1 Survival of microorganisms in the root-filled tooth is the cause of endodontic failure.According to Sjogren et al. for an effective and successful root canal treatment, the microbial infection needs to be eradicated before the root canal system is obturated. 2The persistence or penetration of microorganisms into the canal at the time of obturation leads to high risk of treatment failure. 3everal studies reported the prevalence of bacteria named Enterococcus faecalis ranging from 24 to 77% after endodontic treatment. 4,5The organism is a secondary bacterial invader that resisted intracanal antimicrobial procedures and survive as a monoculture, displays persistent periapical disease in treated root canals. 6Stuart et al. discussed the importance of Enterococcus faecalis in root canal treatment failure, as well as contemporary retreatment strategies. 7Möller et al. studied the influence of periapical tissues of indigenous microbial flora and recovered a significant pathogen, the yeast Candida albicans from persistent periapical lesions of root-filled teeth. 8Ng also found hyphal-like structures which are suggestive of fungi in the interbacterial spaces. 9ndodontic infections caused by these group of organisms are currently treated by mechanical debridement along with chemical irrigants. 10Sodium hypochlorite (NaOCl) is one of the most used irrigant in endodontic therapy. 11It is known for its antimicrobial action.The other functions of NaOCl include ability to partially 1,