In 20th-century America, advances occurred in all aspects of | UPSC SSC Q&A Analysis

  In 20th-century America, advances occurred in all aspects of dentistry. Frederick McKay, a young American dentist practicing in Colorado, observed a condition of mottling of his patients' teeth, in which there was an almost total absence of decay. Following years of research, McKay and others were able to show that this was due to the presence in the drinking water of high amounts of naturally occurring fluoride, which protects teeth against decay. As a result, public health officials established measures to add fluoride to public water supplies in communities around the United States. Since fluoridation was initiated in 1945, dental caries in children have decreased by more than 50 percent.