Antibacterial effects of silver diamine fluoride, potassium iodide and nanosilver fluoride on dual-species biofilm

This study aims to evaluate antibacterial effects of silver diamine fluoride (SDF), SDF/potassium iodide (KI), and nanosilver fluoride (NSF). Antimicrobial activity of sterile saline, 5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), SDF, SDF/KI, NSF, and KI solutions against Streptococcus mutans and Lactobacillus casei was assessed through disc diffusion tests. A dual-species biofilm of S. mutans-L. casei was formed on 48 enamel samples, divided into six groups (n=8). Group 1 was treated with sterile saline, Group 2 with 5% NaOCl, Group 3 with 2% CHX, Group 4 with SDF, Group 5 with SDF/KI, and Group 6 with NSF. The samples were analysed using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Statistical analysis utilized Shapiro-Wilk and Kruskal-Wallis tests and multiple comparisons were conducted using Dunn test. SDF, SDF/KI, and NaOCl displayed significantly higher antibacterial activity against dual-species biofilm compared to NSF and CHX (p<0.050). In conclusion, SDF and SDF/KI demonstrated greater antibacterial activity than NSF. SDF's antibacterial activity was unaffected by KI. Further research is needed to determine the appropriate content and concentration for achieving effective antibacterial activity with NSF. The use of silver-containing materials is increasing in popularity within pediatric dentistry. In this study, an endeavor has been made to assist pediatric dentists in determining which solution might be more advantageous for preventing caries.