Evaluation of Antimicrobial Efficacy of Modified Novel Double Antimicrobial Preparations Against E.Faecalis and C. Albicans: An In-vitro Study

Introduction: The aim of endodontic treatment is the reduction of microbial load inside the root canal, for which Calcium hydroxide {Ca(OH)2} is the most commonly used medicament, which is ineffective against resistant microbes such as E.faecalis and C.albicans. Hence, this study was designed to develop an effective medicament which includes a combination of drugs such as diclofenac, ciprofloxacin, fluconazole, with Ethyl Cellulose (EC). Aim: To evaluate the antimicrobial efficacy of different combinations of Diclofenac, Ciprofloxacin and Fluconazole (DCF) with EC against E.faecalis and C.albicans. Materials and Methods: This in-vitro study, conducted at the Department of Conservative Dentistry and Endodontics in RVS Dental College and Hospital, Coimbatore, Tamil Nadu, India, from September 2024 to January 2025. This included quality control strains of C.albicans and E.faecalis, which were cultured in Tryptic soy broth supplemented with 5% defibrinated sheep blood under anaerobic conditions at 37°C for 45 hours. The two groups (E.faecalis group and C.albicans group) with test materials, which were further divided into three groups: Group I-Calcium hydroxide, Group II-Saline, and Group III-Test drugs. Test drugs were prepared by making different combinations of drugs {Active Pharmaceutical Ingredient (API) powders} of the test drugs, weighed and mixed in 1:10, 2:10, 3:10 ratios with Ethylcellulose polymer (Test drugs-Diclofenac, Ciprofloxacin and Fluconazole). A sample of three different concentrations was examined across all combinations of drug preparations. The antimicrobial activity was assessed using the disk diffusion method. Microbial lawns were prepared on Mueller-Hinton plates with inoculum standardised to 1.5 × 108 CFU/mL. A disk (6 mm diameter) was punched aseptically and filled with 20 µL of test materials. Wassermann filter paper discs were incubated at 37°C for 24 hours, and zones of inhibition were measured using a HiMedia antibiotic scale. Data were statistically analysed using One-way Analysis of Variance (ANOVA) in the Statistical Package for Social Sciences (SPSS) software 24.0. Results: ANOVA statistics revealed that DCF (3:10) consistently demonstrated the highest antimicrobial efficacy against both E.faecalis and C.albicans, with a p-value of <0.001. These findings suggest that novel antibiotic combinations, especially those incorporating Diclofenac, may serve as effective therapeutic agents in combating resistant pathogens. Conclusion: Within the limitations of the study, it can be concluded that DCF (3:10) consistently demonstrated the highest antimicrobial efficacy against both E.faecalis and C.albicans; therefore, it can be considered a potential intracanal medicament against these pathogens.