The model of protein carboxylate - hydroxyapatite surface binding proposed from our recent work.
The enamel that covers the crown, the part of the tooth that is above the gum, is made of a substance called hydroxyapatite.
When enough fluoride from water, supplements, food, or other sources enters the bloodstream and reaches the teeth while the enamel is forming, the fluoride can replace a piece of the hydroxyapatite molecule to form fluorapatite.
The word usage examples above have been gathered from various sources to reflect current and historial usage. They do not represent the opinions of YourDictionary.com.