Antibacterial effect of nano-chlorhexidine on Enterococcus faecalis biofilm in root canal system: An in vitro study

Abstract

BACKGROUND: A new method to improve the properties of the materials is nano-encapsulation, which improves the biological properties, antibacterial activity along with reduction of toxicity. Due to the spread of nano-knowledge, the present study was performed to evaluate the antibacterial effect of nano-chlorhexidine (CHX) on Enterococcus faecalis biofilm in the root canal system. MATERIALS AND METHODS: In this in vitro experimental study, 55 matured single-root mandibular premolars were decoronated and the canals were prepared by single length method up to #F3 ProTaper Universal system. Five teeth were selected as negative control. Then, the teeth were randomly divided into three experimental groups (n = 15) and a positive control group (n = 5). The experimental groups were irrigated with 2 nano- CHX gel, 2 CHX solution, and 5.25 sodium hypochlorite (NaOCl), respectively. Finally, the number of colonies was counted. Kruskal-Wallis test was used to compare the number of colonies among groups. The level of significance was set at P < 0.05. RESULTS: The mean number of colonies in the groups of nano-CHX, NaOCl, CHX, and positive control were obtained as 17.73 +/- 18.69, 35.53 +/- 36.42, 38.8 +/- 31.8, and 96.8 +/- 22.52, respectively. There was a significant decrease in the number of colonies in all the experimental groups compared to the control group (P < 0.05). However, difference in the number of colonies among these three groups was not significant (P > 0.05). CONCLUSION: The use of nano-CHX in removing E. faecalis biofilm from root canal is as effective as the use of CHX and NaOCl.