Silver Diamine Fluoride Inhibits Cariogenic Biofilm Formation in Deciduous Molars

Objectives: Biofilm dependent oral diseases affect most of the world’s population. Evidence shows dental caries is dependent on biofilm accumulation on the tooth surface and its frequent exposure to dietary sugars, causing acid production and a slow but progressive demineralization of the enamel. Topical fluoride varnish (FV) application has been used as an antimicrobial approach to eliminate bacterial growth on the tooth surface. However, studies have shown FV’s inability to maintain its antimicrobial effect overtime. Silver diamine fluoride (SDF) is an effective antimicrobial agent used to arrest caries progression, but stains the teeth black. This study aimed to compare the antimicrobial effects of SDF to FV on extracted deciduous molars with caries.
Methods: Fifteen clinically extracted deciduous molars due to caries were collected, disinfected with 0.1% thymol, and sectioned medially through the lesion. One half of the lesion was treated with SDF (N=10) or FV (N=5), and the other half was untreated. After treatment, the teeth were incubated in Streptococcus mutans UA159 biofilm, 1% sucrose, for 14 days and analyzed using confocal laser scanning microscopy. COMSTAT imaging software was used to compare biofilm viability between SDF and FV treated teeth. The parameters included: average thickness, average surface brightness, and average mean distance.
Results: SDF-treated teeth showed a significant reduction in the average thickness of biofilm compared to untreated teeth (147 µm to 246 µm, respectively, p < 0.01). Conversely, FV treatment did not show a significant decrease. The average mean distance showed no significant differences when comparing treated to untreated teeth for SDF and FV.
Conclusions: These results demonstrate that the antimicrobial effect of SDF is potentially more effective than FV in inhibiting S. mutans biofilm formation and development in deciduous teeth with carious lesions. Further studies should be done in relation to the staining of the teeth surface.