Fluoride

More than 65 years ago - on January 25,1945 - Grand Rapids, Michigan became the world's first city to adjust the level of fluoride in its water supply.  Since that time, fluoridation has dramatically improved the oral health of tens of millions of Americans.  Community water fluoridation is the single most effective public health measure to prevent tooth decay.  The Centers for Disease Control and Prevention has proclaimed community water fluoridation as one of 10 great public health achievements of the 20th century.  Approximately 72.4% of the U.S. population served by public water systems receive the benefit of optimally fluoridated water. 
Fluoridation of community water supplies is simply the adjustment of the existing, naturally occurring fluoride levels in drinking water to an optimal fluoride level recommended by the U.S. Public Health Service (0.7 - 1.2 parts per million) for the prevention of tooth decay.  Water that has been fortified with fluoride is similar to fortifying milk with Vitamin D, table salt with iodine, and bread and cereals with folic acid.
Studies conducted throughout the past 65 years have consistently shown that fluoridation of community water supplies is safe and effective in preventing dental decay in both children and adults. Simply by drinking water, children and adults can benefit from fluoridation's cavity protection whether they are at home, work or school.
Today, studies prove water fluoridation continues to be effective in reducing tooth decay by 20-40%, even in an era with widespread availability of fluoride from other sources, such as fluoride toothpaste. 
Fluoridation is one public health program that actually saves money.   An individual can have a lifetime of fluoridated water for less than the cost of one dental filling.
 
The American Dental Association continues to endorse fluoridation of community water supplies as safe and effective for preventing tooth decay.  This support has been the Association's position since policy was first adopted in 1950.  The ADA's policies regarding community water fluoridation are based on the overwhelming weight of peer-reviewed, credible scientific evidence.  The ADA, along with state and local dental societies, continues to work with federal, state and local agencies to increase the number of communities benefiting from water fluoridation.        

Article courtesy of ada.org