Public Health · single question
What is the most clinically relevant pharmacological property of fluoride in preventing dental caries?
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Correct answer: B. Substantivity (prolonged retention on tooth surfaces)
Substantivity refers to the ability of an agent to bind to oral surfaces and release slowly over time, maintaining prolonged therapeutic effect. For fluoride, substantivity explains how fluoride-containing toothpastes, varnishes, and rinses provide extended anti-caries protection after application. This is more clinically relevant than peak bioavailability. Substantivity is also an important concept for chlorhexidine. Bioavailability matters for systemic fluoride supplementation but substantivity drives the topical anticaries mechanism.