Benefits l Fluoridation Facts 19 • In Grand Rapids, Michigan, the first city in the world to fluoridate its water supply, a 15-year landmark study showed that children who consumed fluoridated water from birth had 50-63% less tooth decay than children who had been examined during the original baseline survey completed in nonfluoridated Muskegon, Michigan.37 • In 1985, the National Preventive Dentistry Demonstration Program38 analyzed various types and combinations of school-based preventive dental services to determine the cost and effectiveness of these types of prevention programs. Ten sites from across the nation were selected. Five of the sites had fluoridated water and five did not. Over 20,000 second and fifth graders participated in the study over a period of four years. Students were examined and assigned by site to one or a combination of the following groups: o biweekly in class brushing and flossing plus a home supply of fluoride toothpaste and dental health lessons (ten per year) o in-class daily fluoride tablets (in nonfluoridated areas) o in-school weekly fluoride mouthrinsing o in-school professionally applied topical fluoride o in-school professionally applied dental sealants, and o a control.38 After four years, approximately 50% of the original students were examined again. The study affirmed the value and effectiveness of community water fluoridation. At the sites where the community water was fluoridated, students had substantially fewer cavities, as compared to those sites without fluoridated water where the same preventive measures were implemented. In addition, while sealants were determined to be an effective prevention method, the cost of a sealant program was substantially more than the cost of fluoridating the community water, confirming fluoridation as the most cost-effective preventive option.38 • In another review of studies conducted from 1976 through 1987 and published in 1989,39 data for different age groups were separated into categories by the types of teeth present in the mouth. The results demonstrated a 30-60% reduction in tooth decay in primary teeth, a 20- 40% reduction in the mixed dentition (having both baby and adult teeth) and a 15%-35% reduction in the permanent dentition (adults and seniors) for those living in fluoridated communities.39 • In the United States, an epidemiological survey of nearly 40,000 schoolchildren was completed in 1987.40 Nearly 50% of the children aged 5 to 17 years who participated in the study were decay free in their permanent teeth, which was a major change from a similar survey conducted in 1980 in which approximately 37% were decay free. This dramatic decline in decay rates was attributed primarily to the widespread use of fluoride in community water supplies, toothpastes, dietary fluoride supplements and mouthrinses. Although decay rates had declined overall, data also revealed that the decay rate was 25% lower in children with continuous residence in fluoridated communities when the data were adjusted to control for exposure to dietary fluoride supplements and topical fluoride treatments.40 • In 1993, the results of 113 studies in 23 countries (over half of the studies were from the U.S.) were compiled and analyzed.41 This review provided effectiveness data for 66 studies of primary teeth and 86 studies of permanent teeth. The analysis of the studies demonstrated a 40-49% decay reduction for primary (baby) teeth and a 50-59% decay reduction for permanent (adult) teeth for those living in fluoridated communities.41 • A comprehensive analysis of the first 50 years of community water fluoridation in the United States concluded that “Community water fluoridation is one of the most successful public health disease prevention programs ever initiated.”42 While noting that the difference in tooth decay between optimally fluoridated communities and fluoride-deficient communities was smaller than in the early days of fluoridation, largely due to additional sources of fluoride, the difference was still significant and the benefits for adults should be emphasized. The report ended by noting that water fluoridation is a near-ideal public health measure whose benefits can transcend racial, ethnic, socioeconomic and regional differences.42 The systematic reviews and studies noted above provide science-based evidence that, for more than 70 years, fluoridation has been effective in helping to prevent tooth decay.