Final answer:
Fluoride is absorbed directly into the teeth and gums, helping to rebuild and strengthen enamel and preventing tooth decay. It can become incorporated into tooth enamel, making it more resistant to acids produced by oral bacteria. Fluoride is found in toothpaste, mouth rinses, and tap water through community water fluoridation.
Step-by-step explanation:
Fluoride is absorbed directly into the teeth and gums. It helps to rebuild and strengthen the tooth's surface, or enamel, preventing tooth decay. Fluoride can become incorporated into the hydroxyapatite of tooth enamel, making it more resistant to corrosive acids produced by oral bacteria. It also enhances the uptake of calcium and phosphate ions, promoting remineralization. Fluoride is found in toothpaste, mouth rinses, and is commonly added to tap water through community water fluoridation.