Sodium fluoride

Sodium fluoride releases fluoride ions (F-) in the oral cavity. These fluoride ions can react with hydroxyapatite in tooth enamel to form fluorapatite. Fluorapatite has lower solubility and is much more resistant to acid than hydroxyapatite, making teeth more tolerant to erosion caused by acids produced by bacteria. In addition, fluoride ions can enter oral bacteria such as Streptococcus mutans. In an acidic environment, they form hydrofluoric acid, which then inhibits the bacterial enzyme enolase, disrupts glycolysis, reduces lactic acid production, decreases the acid-producing ability of dental plaque, and lowers the risk of tooth decay.