Public Health · single question
What is the mechanism of action of fluoride in preventing dental caries?
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Correct answer: C. Decreases the solubility of calcium phosphate in tooth enamel (forms fluorapatite)
- A. Increased salivary flow is a caries-protective factor but is not the mechanism of fluoride action.
- B. Fluoride does not directly block plaque acid production as its primary mechanism.
- C. Correct. Fluoride reacts with hydroxyapatite (HA) in enamel to form fluorapatite (FA), which is more resistant to acid dissolution. Fluoride also promotes remineralization and reduces solubility of calcium phosphate crystals — making enamel more resistant to cariogenic acid attack.
- D. Fluoride has some antibacterial properties but its primary caries-preventive effect is not direct bacterial killing.