19 16 Mckay and Black reported the papers about dental fluorosis to the American public for the first time after epidemiological and histopathological investigation. After years of investigation of thousands of people, MacKay pointed out that the caries rate of 1928 dental fluorosis population is not high.

The fluoride water source is to add a proper amount of fluoride to tap water. The most suitable concentration of China is 1 liter of water, containing 0.6 ~ 0.8 mg of fluorine.

Fluoride can prevent dental caries, which is the greatest contribution of preventive stomatology to mankind in the 20th century. Fluorine exists widely in nature, and human body can ingest fluorine from drinking water, food and air. Fluorine is an essential trace element for human health, and a proper amount of fluorine has a positive effect on the metabolism of the body. Fluoride caries prevention can be divided into systemic application and local application. Among them, the most classic systemic application method is to adjust the fluoride concentration in drinking water; The most common way to use fluoride locally is to brush your teeth with fluoride toothpaste, in addition to professional fluoride application.