What is the commonly used concentration of silver diamine fluoride solution for caries arrest?

• A. 5%
• B. 10%
• C. 38%
• D. 50%

Answer: (C)

Silver diamine fluoride is used to arrest caries because the formulation delivers enough antimicrobial silver ions to stop the bacteria and enough fluoride to aid remineralization of demineralized dentin. The concentration most commonly used and studied for this purpose is 38%, which is the standard product found in practice. This level has been shown in clinical trials and guidelines to be effective at arresting caries with a simple, non-invasive application. Lower concentrations would generally be less effective at stopping progression, while 50% is not the standard commercially available preparation. When applied, the lesion often darkens due to silver interaction, signaling arrest.