What is the major mechanism of action of fluoride in preventing dental caries?

Fluoride's primary mechanism in the prevention of dental caries is the enhancement of remineralization. This process involves the uptake of fluoride by tooth enamel, where it promotes the deposition of minerals such as calcium and phosphate. When teeth are subjected to acidic conditions from bacterial metabolism, demineralization occurs, leading to the loss of these critical minerals. Fluoride enhances the remineralization process by not only promoting the return of minerals but also by forming a more stable and less soluble compound called fluorapatite, which is less prone to acid attack compared to hydroxyapatite.

This means fluoride does not merely stop the progression of caries but actively aids in the repair of early lesions before they develop into cavities. Understanding this mechanism highlights the importance of fluoride in preventive dental care, such as in the use of fluoride toothpaste, mouth rinses, and professional applications, as it directly aids in strengthening enamel and protecting against future caries formation.