The protective role of fluorides against dental caries was not recognized until the mid-1930s, when the epidemiologic studies demonstrated that drinking naturally fluoridated water had fewer cavities than those in matched populations with water supplies that were low in fluorides. Fluoride used for dental applications is available from two major sources: products containing fluoride in their formulations (topical) and fluorides that are ingested into the body from treated water and other sources (systemic). Topical fluorides comprise of mouth rinses, toothpastes and professionally applied topical fluorides. Different fluoride compounds, different vehicles, and vastly different concentrations have been used different frequencies and duration of application. In general high concentration agents are applied professionally and low concentration fluoride agents are applied by individual themselves.