Fluoride is found naturally in soil, water, foods, and several minerals, such as fluorapatite and fluorite. Fluoride is also synthesized in laboratories. Synthesized fluoride is commonly added to drinking water, toothpaste, mouthwashes and various chemical products.
Water authorities add fluoride to tap-water because they say it reduces the prevalence of tooth decay in the local population.
Most of the countries in Europe which do not have water fluoridation did not find that their incidences of dental cavities increased. In Germany and Finland, for example, decay rates either remained stable or continued in their downward trend after they stopped adding fluoride to their drinking water.
Excessive exposure to high concentrations of fluoride during tooth development (during childhood) can result in tiny white streaks or specks in the enamel of the tooth in mild cases of dental fluorosis.
Of greatest concern is the aesthetic changes that occur in the permanent teeth among children who are exposed to too much fluoride between the ages of 20 and 30 months. According to dentists, the critical period of fluoride exposure is between 1 and 4 years of age – the risk goes away after the age of 8 years. Symptom-severity depends on several factors, including the child’s age, weight, degree of physical activity, bone growth, diet and individual response.