Most countries in Europe have experienced substantial declines in cavities without the use of water fluoridation.[1] For example, in Finland and Germany, tooth decay rates remained stable or continued to decline after water fluoridation stopped. Fluoridation may be useful in the U.S. because unlike most European countries, the U.S. does not have school-based dental care, many children do not visit a dentist regularly, and for many U.S. children water fluoridation is the prime source of exposure to fluoride.[59] The effectiveness of water fluoridation can vary according to circumstances such as whether preventive dental care is free to all children.[60]