Why does fluoride help clean my teeth?

Cavity prevention: Fluoride in toothpaste is not there to necessarily clean teeth. It acts as a preventative of caries or cavities. Fluoride in the presence of dissolved minerals in the saliva acts as a catalyst of remineralization. When plaque acids dissolve tooth structure fluoride, calcium, and phosphate ions fill in the areas of decalcification to form fluoroappatite crystals which are more resistant to acid.

Fluoride Clean: Fluoride strengthens the enamel on your teeth making it more difficult for decay to start. It is added to toothpaste for this reason. It does not clean teeth. It is the action of the brush and flossing that clean teeth.

Strengthens enamel: Fluoride helps by making the enamel of your teeth more resistant to acid. Fluoride can also reverse cavities that are starting to form on a microscopic level. When present it also interferes with the bacteria in your mouth so that they produce less acid and are less able to stick to your teeth.