Evaluation of Cytotoxicity and Antimicrobial Activity of Experimental Composites Containing Chitosan-Silver Oxide Particles Against Two Main Pathogenic Bacteria in Periodontal Disease.

Introduction: Bacterial biofilm is known as the main cause of periodontal disease. Generally, the anaerobic Gram-negative, such as Porphyromonas gingivalis and Fusobacterium nucleatum, are considered the most identified bacteria.

Objective: This study aimed to investigate the antimicrobial effect and cytotoxicity of two experimental composites containing chitosan-silver oxide (CH-Ag₂O) particles.

Materials and methods: Four experimental groups, including Ag2O and CH, along with two composites of CH-Ag₂O 20 and CH-Ag₂O 60 mg, were prepared. Antimicrobial activity was performed against Porphyromonas gingivalis (ATCC#33277) and Fusobacterium nucleatum (ATCC#25586) using the agar dilution method. Moreover, the cytotoxicity assay was performed on human gingival fibroblasts (HGF) by the use of the MTT method. The obtained data were analyzed with descriptive methods, one-way ANOVA, and Tukey's LSD tests.

Results: The antibacterial activity of both composites was higher than both CH and Ag₂O, and the greatest antibacterial properties were presented in CH-Ag₂O 60. In all three measurements (24, 48, and 72 h), the greatest cytotoxicity was seen in Ag₂O, followed by CH, CH-Ag₂O 20, and CHAg₂O 60 in descending order, respectively. The cytotoxicity of these components was related to the concentration and not to the time of exposure. The results showed that Ag₂O in 3.7 and 7.5 μg/ml concentrations and CH-containing groups in 250 and 500 μg/ml were toxic to the cultured HGF.

Conclusion: The experimental composite containing CH-Ag₂O 60 showed the greatest antibacterial properties against two periodontal pathogens evaluated. In order to clarify the clinical significance of composite cytotoxicity, further clinical studies are necessary.