Public Health · single question
What property makes fluoride varnish particularly effective?
Show answer and explanation
Correct answer: D. Substantivity — prolonged retention and slow fluoride release at the tooth surface
- A. Tubule sealing is a desensitizing effect of some agents, not the caries mechanism of varnish.
- B. Fluoride reduces bacterial metabolism (enolase inhibition) but is not a bactericidal agent.
- C. Varnish formulations are neutral or slightly acidic; pH is not the mechanism.
- D. Correct. The resin carrier sets on contact with saliva and adheres for hours, maintaining an elevated fluoride reservoir far longer than a rinse or gel — this is substantivity, and it is why varnish outperforms other topical vehicles.