Comparative Study of the Synergistic Antimicrobial Efficacy of Chitosan with Chlorhexidine, Silver, and Propolis in Human Saliva

Abstract

Purpose: The aim of the study was to evaluate and compare the synergistic antimicrobial effects of chitosan with chlorhexidine, silver, and propolis in human saliva. Materials and method: High and low concentrations of chitosan solution were prepared and added to the chlorhexidine solution, silver nitrate, and propolis extract. Antimicrobial testing was performed using colony-forming units (CFU) and disc diffusion tests with chitosan solution in both concentrations as a positive control. Biofilms containing Streptococcus mutans (S. mutans) were grown on 56 enamel blocks and subjected to the treatment solutions then diluted and grown on specific S. mutans media for colony counting. Inhibition zones were measured by immersing filter paper discs in the treatment solutions and incubating them on agar plates inoculated with S. mutans bacteria. Results: Statistical analysis showed that 5% chitosan/ nanosilver mixture (Chit/AgNps) had the highest synergistic antimicrobial effect in both tests with a mean value of (8.571 CFU/mL) for CFU and (44 mm) for disc diffusion. Conclusion: 5% Chit/AgNps showed the most promising antimicrobial efficacy against S.mutans among all mixtures.