How often should fluoride varnish typically be applied to help prevent caries in high-risk preschoolers?

• A. Every 12 months.
• B. Every 3–6 months, with more frequent applications in high-risk children.
• C. Every 2 weeks.
• D. Never.

Answer: (B)

Regular topical fluoride exposure is needed to keep enamel resistant to decay, especially in kids who are at high risk for caries. Fluoride varnish provides a protective fluoride layer for a few months, so the interval must be frequent enough to maintain ongoing protection. For preschoolers at high risk, the recommended approach is to apply fluoride varnish every 3–6 months, with even more frequent applications if the risk remains very high. This keeps the caries-prevention effect active over time rather than letting protection lapse between visits.

Choosing only one annual application would miss several months of protection, and applying every two weeks is unnecessary and impractical. Never applying fluoride varnish would forgo a proven preventive measure.