Antimicrobial Efficacy of Different Concentrations of Sodium Hypochlorite in the Elimination of Enterococcus Faecalis: An In-vitro Study

Abstract

Introduction: Primary teeth are equally important as permanent teeth. Endodontic therapy aids in the preservation and maintenance of extremely carious primary teeth. For root canal therapy to be successful, root canals must be properly prepared and effectively irrigated. Sodium Hypochlorite (NaOCl) has been the gold standard for root canal treatment of primary teeth. However, there are a few drawbacks to using higher concentrations of sodium hypochlorite, such as toxic reactions from its apical penetration. In addition, an excess of irrigation fluid via the apical region could harm the permanent tooth underneath. Therefore, it is crucial to select the proper concentration to preserve the delicate balance between effectiveness and safety. Aim: The present in-vitro study was conducted in the city of Chennai, Tamil Nadu, between March and June 2022. The study aimed to evaluate the effectiveness of lower concentrations of sodium hypochlorite, such as 1%, 0.5%, and 0.25%, against Enterococcus faecalis. Materials and Methods: The antibacterial activity of different concentrations of sodium hypochlorite (1%, 0.5%, and 0.25%) against Enterococcus faecalis was performed using Muller Hinton agar. Three Mueller Hinton agar plates were prepared and sterilised for 15 minutes for each concentration. The volumes used were 25 μL, 50 μL, and 100 μL, respectively. E. faecalis was swabbed and poured into the sterilised plates. The plates were incubated for 24 hours at 37°C. After incubation, the plates were examined, and their zone of Inhibition was determined. ANOVA test was applied with Post-hoc Tukey’s analysis. Results: One-way ANOVA test showed that there was a significant difference with a p-value <0.001 in all three groups. Post-hoc Tukey’s analysis was done, and the test showed that the highest zone of inhibition was seen with 1% sodium hypochlorite at 100 μL, with zone diameter of 39 mm, and the least zone of inhibition was seen with 0.25% sodium hypochlorite solution at 25 μL, with zone diamter of 22 mm. Conclusion: The results of the present study show that a 1% sodium hypochlorite solution can be used to successfully disinfect root canals, indicating its potential as an effective antimicrobial agent in endodontic procedures.