Does fluoride produce fluorapatite crystals to help prevent dental caries?

Enamel: Fluoride binds to the enamel to make it harder and more resistant to decay.

Esentially yes: Your teeth are primarily made up of hydroxyapetite and they get demineralized by acidic environments created by our food and bacteria in our mouth. Fluoride replaces the hydroxide and remineralizes and becomes fluorapetite which is actually stronger and more dense helping to reduce decay and prevent continued damage.