To curb a rise in dental fluorosis in the United States, a condition in which teeth become discolored or pitted from excessive fluoride exposure, the US Department of Health and Human Services (DHHS) has suggested lowering the amount of fluoride added to municipal water.
Since the 1960s, fluoride has been added to drinking water in many communities to prevent tooth decay, a measure that the Centers for Disease Control and Prevention has cited as one of the 10 greatest public health achievements of the 20th century. However, US dentists are seeing higher levels of fluorosis, predominantly of the mild form involving tooth discoloration, perhaps because individuals are now exposed to fluoride from many sources, including drinking water, toothpaste, mouthwash, and fluoride treatments applied in dentists' offices.
Kuehn BM. Fluoride Recommendations. JAMA. 2011;305(8):770. doi:10.1001/jama.2011.181