Which fluoride is added to water

Spring Winter Fall Issue Archive. Harvard T. Harvard Public Health Magazine expand child menu. Search for:. Countries that do not fluoridate their water have also seen big drops in the rate of cavities.

The Evidence Beginning in the early 20th century, scientists linked high levels of naturally occurring fluoride in certain community water supplies to low levels of tooth decay. Increase in requests for dental care. Natural water fluoride under optimal levels. Latest news Could 'cupping' technique boost vaccine delivery? Scientists identify new cause of vascular injury in type 2 diabetes.

Adolescent depression: Could school screening help? Related Coverage. Why do we have fluoride in our water? Is it safe to drink raw water? Medically reviewed by Debra Rose Wilson, Ph.

Caring for teeth and gums. What is the best kind of toothpaste to use? They suggested that their findings might support the argument that caries can continue to fall if the concentration of fluoride is reduced from 1 part per million ppm to below 0. The previous figure, in force from to , was 0. In , it was revised to the lower limit. It sets the maximum allowable level at 4 ppm , and a secondary maximum level at 2 ppm.

People are asked to inform the EPA if levels are above 2 ppm. Levels above 4 ppm could be hazardous. In areas where water naturally contains higher levels of fluoride, community water systems must ensure that the maximum level is no higher than 4 ppm. Read the article in Spanish. A filling seals a hole, or cavity, in the tooth, preventing further damage, pain, and infection. Learn what having a filling entails here. Cavity pain can range from mild to intense. Cavities that cause pain are usually deep enough to have affected a nerve.

Learn more about cavity pain…. Twelve years ago, Juneau, AK, stopped adding fluoride to community water sources. A newly published study looks at how this has affected its…. Cracks in teeth vary in severity. Some are mild and invisible, while others are significant and cause a lot of pain. Dentists judge the extent of…. In the s, scientists examined the relationship between tooth decay in children and naturally occurring fluoride in drinking water.

The study found that children who drank water with naturally high levels of fluoride had less tooth decay. Many suffered from toothaches and painful extractions—often losing permanent teeth, including molars, even as teenagers. After much scientific research , in , the city of Grand Rapids, Michigan, was the first to add fluoride to its city water system in order to provide residents with the benefits of fluoride.

This process of testing the water supply for fluoride and adjusting it to the right amount to prevent cavities is called community water fluoridation.

Because of its contribution to the dramatic decline in tooth decay over the past 75 years , CDC named community water fluoridation as 1 of 10 great public health achievements of the 20th century. See where your state ranks in percent of the population that receives water with fluoride. Community water fluoridation has been shown to save money, both for families and the health care system.

The return on investment for community water fluoridation varies with size of the community, increasing as the community size increases. Community water fluoridation is cost-saving, even for small communities. Learn more about this goal external icon.