Fluoride is the mineral commonly used to prevent cavities. It works by strengthening tooth enamel, making it more resistant to acid attacks from plaque bacteria and sugars in the mouth. Fluoride can be found in various sources, including fluoridated water, toothpaste, and professional dental treatments. It promotes remineralization—the process where minerals are redeposited in tooth enamel after being removed by acids. The consistent exposure to fluoride over time contributes significantly to a decrease in the incidence of dental caries, making it a key component of oral hygiene practices.