Final answer:
Fluoride released from sealants helps form fluorapatite in tooth enamel, making it more resistant to decay and enhancing remineralization. It also acts as a bacteriostatic agent. Excessive fluoride, however, can cause fluorosis.
Step-by-step explanation:
When fluoride is released from dental sealants, it creates a chemical reaction that helps prevent tooth decay. The fluoride ion helps protect teeth by reacting with hydroxyapatite, which is present in tooth enamel, to form fluorapatite, Ca5(PO4)3F, which is more resistant to acid attacks. This resistance comes from fluorapatite's lack of a hydroxide ion, making it less soluble than hydroxyapatite. Fluoride also enhances the uptake of calcium and phosphate ions in tooth enamel, promoting remineralization.
Additionally, fluoride serves as a bacteriostatic agent that accumulates in plaque-forming bacteria, interfering with their metabolism and decreasing their acid production. Common sources of fluoride include toothpaste, mouthwashes, and fluoridated water, which contribute to dental health by providing frequent and consistent contact with low levels of fluoride, strengthening the enamel and preventing cavities.
It's also important to note that high levels of fluoride in groundwater can lead to dental and skeletal fluorosis, indicating the need for the right balance of fluoride exposure for optimal dental health.