Frederick McKay

Frederick McKay was an American dentist who observed a condition called mottled enamel in his patients' teeth. This condition, characterized by spotting on the enamel, was associated with a near-complete absence of tooth decay. After extensive research, McKay and his colleagues determined that the cause was high levels of naturally occurring fluoride in the local drinking water. This discovery led to the practice of water fluoridation, where fluoride compounds are added to public water supplies to reduce dental caries (cavities). Since the initiation of fluoridation in 1945, dental caries in children have significantly decreased. While beneficial for dental health, excessive fluoride can cause tooth mottling and, in higher doses, bone abnormalities.12