Safe Drinking Water Act and Water Surveillance Practice Test

Fluoride in drinking water is used to protect teeth. It strengthens enamel and helps teeth remineralize after acid attacks from plaque bacteria, making them more resistant to decay. This is especially helpful for children, whose permanent teeth are forming and erupting, so fluoridated water lowers the incidence of dental caries in the population.

The other ideas don’t fit because disinfecting water is the job of chlorine or other disinfectants, not fluoride; water hardness comes from minerals like calcium and magnesium, which fluoride does not meaningfully change; and fluoride isn’t added to improve taste. At the recommended levels, fluoride provides dental protection with little or no noticeable change in taste.