Comparative Evaluation of the Antimicrobial Efficacy of 20% Chlorhexidine, 3% Sodium Hypochlorite, and Dexamethasone Acetate with Thymol as a Root Canal Disinfectant against Enterococcus faecalis: An In-vitro Feasibility Study

Introduction: Endodontic therapy aims to eliminate microbial infection from the root canal system. Enterococcus faecalis, known for its resistance and biofilm-forming capacity, presents significant challenges. This study evaluates the antimicrobial efficacy of 20% chlorhexidine (biosol), dexamethasone acetate with thymol (cresophene), and 3% sodium hypochlorite (NaOCl). Methods: Eighty extracted uniradicular teeth were inoculated with E. faecalis and randomly assigned to four groups: Group I (biosol), Group II (cresophene), Group III (3% NaOCl), and Group IV (control). After irrigation, samples were incubated and assessed microbiologically after 48 hours to determine bacterial reduction. Results: Group I (biosol) demonstrated the highest efficacy with a 90.15% reduction in bacterial load, closely followed by Group II (cresophene) at 89.85%. Group III (NaOCl) showed a 75.57% reduction. Group IV (control) had the highest bacterial persistence. Differences between Group I and Groups III/IV were statistically significant (p < 0.0001). Discussion: The superior performance of biosol and cresophene highlights their potential as effective root canal disinfectants. The substantivity of biosol may help prevent recolonization, while the anti-inflammatory and antifungal properties of cresophene further support disinfection. Although NaOCl remains widely used, its limitations underscore the need for alternatives. Further research is warranted to assess safety, cytotoxicity, and clinical efficacy, particularly given the high concentration of chlorhexidine used. Conclusion: Both biosol and cresophene demonstrated strong antimicrobial efficacy against E. faecalis, supporting their potential application in clinical endodontics. However, future clinical trials are necessary to validate these findings.