Carnosic Acid as an intracanal medicament performs better than triple antibiotic paste and calcium hydroxide to eradicate Enterococcus faecalis from root canal: An in vitro confocal laser scanning microscopic study

BACKGROUND: Carnosic acid is an herbal derivative with potent antioxidant, anti-inflammatory, antimicrobial, and anticancer properties. AIM: Comparative evaluation of the antimicrobial potential of carnosic acid, calcium hydroxide, and triple antibiotic paste as intracanal medicaments against Enterococcus faecalis. SETTINGS AND DESIGN: Department of Conservative Dentistry and Microbiology, an in vitro study. MATERIALS AND METHODS: Fifty-two extracted single-rooted human teeth were decoronated and chemomechanical preparation was performed. The specimens were secured in the center of screw-capped vials and autoclaved. A strain of E. faecalis was inoculated into the canals and grown for 72 h. The teeth were divided into: Group I-Ca(OH)(2), Group II- triple antibiotic paste (TAP), Group III-Carnosic acid, and Group IV-Negative control. The medicaments were applied in the canal and left for 14 days. The specimens were sectioned transversely at three levels to create dentinal discs and observed under the confocal laser scanning microscopic (CLSM). Images were analyzed, and quantification of bacteria was done using the Image J software. STATISTICAL ANALYSIS: Mean percentage of live/dead bacteria was analyzed using One-way ANOVA and Post hoc Tukey test. RESULTS: Mean percentages of live and dead bacteria were seen under CLSM in Group I, Group II, and Group III were (4.44 ± 2.87, 4.56 ± 2.93, 1.61 ± 1.90), and (4.59 ± 3.04, 4.25 ± 2.98, 1.70 ± 1.99), respectively, with least mean percentages for live and dead bacteria in carnosic acid (Group III). CONCLUSION: Carnosic acid showed better antimicrobial efficacy against E. faecalis than TAP and Ca(OH)(2) by showing a low percentage of both live and dead bacteria.