Antifungal Efficacy of Green Tea Extract against Candida Albicans Biofilm on Tooth Substrate

OBJECTIVES: Biomechanical preparation and irrigation with antimicrobial solutions are necessary to disinfect the root canal space. This in vitro study aimed to examine the antifungal effect of green tea extract on Candida albicans biofilm formed on tooth substrate. MATERIALS AND METHODS: Minimum fungicidal concentration (MFC) and minimum inhibitory concentration at which 90% of the isolates were inhibited (MIC90) were studied using green tea extract and sodium hypochlorite with the broth macro-dilution method. Then, anti-candida effects of this extract were tested on tooth substrates of 45 extracted single-canal premolar teeth. After biomechanical cleaning of the root canals, the teeth were sectioned vertically and randomly divided into three groups of 30. All the samples were infected with C. albicans (PTCC 5027) and exposed to the test solutions (sodium hypochlorite, green tea, normal saline) for five, 10 and 15 minutes. Data analyses of the samples were performed using two-way ANOVA. RESULTS: The average number of microorganisms showed a significant decrease after five, 10 and 15 minutes of exposure to green tea extract and sodium hypochlorite. The average number of C. albicans in green tea extract and sodium hypochlorite groups decreased to 1/3 and 1/2 of the initial values, respectively. CONCLUSION: Antifungal activity of green tea extract was time-dependent and its inhibitory action did not decrease significantly over time. It is recommended to consider other properties of green tea such as tissue solubility, impact on dentin structure and use as an intracanal medicament or for smear layer removal in the clinical setting.