- Fluoride plays a crucial role in the prevention of dental caries primarily through its interaction with the mineral component of tooth enamel.
- The main way it provides protection is by forming fluorapatite crystals within the enamel.

- Fluorapatite is a more acid-resistant form of hydroxyapatite, the natural mineral structure in enamel. This substitution enhances the enamel's resistance to acid demineralization caused by bacterial metabolism of sugars.
- When fluoride ions incorporate into the enamel, they reduce its solubility in acidic conditions, thereby strengthening the enamel and making it less prone to decay.
- Although fluoride also has some antimicrobial effects, such as the inhibition of bacterial enzymes, this is a secondary mechanism and not the primary mode of action in caries prevention.

In summary, the formation of fluorapatite crystals by fluoride incorporation into enamel is the key process that enhances enamel resistance to acid attack and thus prevents dental caries effectively.

Reference: Fejerskov O, Kidd E. Dental Caries: The Disease and Its Clinical Management, 3rd Edition, Chapter 3/Pages 45-47