Antimicrobial Efficacy of Methanolic Extracts of Tinospora cordifolia and Cinnamomum zeylanicum against Enterococcus faecalis Biofilm Production: An In-vitro Study

Introduction: The robust nature of Enterococcus faecalis (E. faecalis) biofilms poses substantial challenges during endodontic therapy. Conventional irrigants, such as Sodium Hypochlorite (NaOCl) and Chlorhexidine (CHX), are effective but are cytotoxic and have deleterious effects on fracture resistance. Natural alternatives like Tinospora cordifolia (TC) and Cinnamomum zeylanicum (CZ) offer promising antimicrobial properties against biofilms. Aim: To evaluate the antimicrobial efficacy of TC and CZ against 21-day-old E. faecalis biofilms, compared to conventional irrigants. Materials and Methods: This an in-vitro study was conducted in the Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Chennai, India, between February 2024 and May 2024. Methanolic extracts of TC and CZ were prepared, and Minimum Inhibitory Concentrations (MICs) were determined using an agar diffusion test. Thirty-one singlerooted teeth were vertically sectioned (N=62) and incubated in an E. faecalis suspension for 21 days to establish biofilms, confirmed via Scanning Electron Microscopy (SEM). Samples were categorised into five groups (n=12): TC, CZ, NaOCl, CHX, and saline (control) and each group was treated with 2 mL of the respective solution for 10 minutes. Microbial load was assessed quantitatively via Colony-forming Unit (CFU) counts/mL and qualitatively. CFU data were expressed as mean±SD. One-way Analysis of Variance (ANOVA) with Tukey’s post-hoc test was used for intergroup comparison. Results: The findings revealed a statistically significant variation among the tested irrigants. MIC was 7 mg/L for TC extract and 7.5 mg/L for CZ extract. CFU counts/mL (mean±SD) were lowest for 5.25% NaOCl (0) and 2% CHX (0), followed by TC (15.430±4.320×107), CZ (20.564±2.234×107), and saline (34.45±5.653×107). Conclusion: Both methanolic extracts of TC and CZ show considerable antimicrobial efficacies against E. faecalis biofilm as compared to the negative control, suggesting their potential as alternative or adjunctive endodontic irrigants.