What instrument is used to apply the SDF solution to the lesion?

• A. Microbrush
• B. Cotton pellet
• C. Toothpaste brush
• D. Syringe tip

Answer: (A)

Applying silver diamine fluoride to a lesion requires a precise applicator that can deliver a small amount of liquid directly to the carious area. A microbrush fits this need because its tiny, soft brush tip allows controlled, localized placement right onto the lesion, helping the solution stay in contact with the carious tissue long enough for the SDF to work. It also minimizes contact with surrounding tissues, reducing the chance of excess staining or spread. Cotton pellets are mainly for drying or blotting, not for targeted application. A toothpaste brush is too large and imprecise, and a syringe tip is not ideal for painting the lesion and can lead to dripping.