The recommendations made at that time recently have been reassessed because of what seems to be an increased incidence of dental fluorosis in children living in the United States. Dental fluorosis appears during tooth formation and is caused by excessive fluoride ingestion, which leads to enamel protein retention, hypomineralization of the dental enamel and dentin, and disruption of crystal formation. The effect is cosmetic only, ranging from barely perceptible white striations or specs to confluent areas of pitting or brownish gray staining.
Teeth affected by fluorosis seem to continue to be resistant to dental caries.
The main sources of fluoride include fluoridated water, foods or drinks reconstituted or prepared with fluoridated water, dentifrices, and fluoride supplements. Water is not fluoridated to a uniform level throughout the United States, and young children ingest significant, but variable amounts of fluoride while brushing their teeth with fluoride-containing toothpaste. Because both of these sources of fluoride are difficult to control, attention has been directed again at the dosage of fluoride supplements to attempt to prevent dental fluorosis. In January 1994, a Dietary Fluoride Workshop sponsored by the American Dental Association was convened to address the issue of dental fluorosis. Although children can receive substantial amounts of fluoride from beverages and dentifrices, the experts at this workshop thought the only source of fluoride that could be easily altered was the supplement prescribed by physicians and dentists.