Which are topical mechanisms of fluoride?

• A. Inhibiting tooth demineralization
• B. Enhancing remineralization
• C. Inhibiting bacterial metabolism
• D. All of the above

Answer: (D)

Fluoride protects teeth at the surface through multiple actions. It makes enamel less soluble during acid exposure, helping to prevent mineral loss (inhibiting demineralization). It also promotes remineralization by forming fluorapatite and stabilizing mineral uptake at the surface, aiding recovery of early lesions. In addition, fluoride can reduce acid production by plaque bacteria, dampening their metabolism. Taken together, these surface-level effects cover all the described mechanisms, so the best answer is that all of these are topical actions of fluoride.