Tooth decay declined substantially in prevalence and severity when Hong Kong children consumed less fluoride, indicative of a world-wide scientific trend revealing, with fluoride, less is best; none is better.
In 1988, Hong Kong reduced water fluoride levels from 0.7 parts per million (ppm) to 0.5 ppm. By 1995, 31% fewer 11-year-olds had cavities with a 42% reduction in average cavity rates, according to the Hong Kong Public Health Bulletin (1). Similar reductions occurred in 1978 when Hong Kong's fluoridation rates were first cut from 1 ppm to 0.7 ppm (2).
Hong Kong's dental health is superior to the United States' (3), even though U.S. children consume 1 ppm fluoridated water and brush with 1,000 ppm fluoridated toothpaste. And Hong Kong children use lower concentrated (500 ppm) fluoridated toothpaste (4).
Evidence that eliminating fluoridation lessens decay:
* Seven years after fluoridation ended in LaSalud, Cuba, cavities remained low in 6- to 9-year-olds, decreased in 10- to 11-year-olds, and significantly decreased in 12- to 13-year-olds, while caries-free children increased dramatically, according to Caries Research (5).
* East German scientists report, "following the cessation of water fluoridation in the cities Chemnitz . . . and Plauen, a significant fall in caries prevalence was observed," according to Community Dentistry and Oral Epidemiology (6) . . . Surveys in the formerly-fluoridated towns of Spremberg and Zittau found "caries levels for the 12-year-olds of both towns significantly decreased... following the cessation of water fluoridation."
* In British Columbia, Canada, "the prevalence of caries decreased over time in the fluoridation-ended community while remaining unchanged in the fluoridated community," reported in Community Dentistry and Oral Epidemiology (7).
* In 1973, the Dutch town of Tiel stopped fluoridation. Researchers counted decayed, missing, and filled permanent tooth surfaces (DMFS) of Tiel's 15-year olds, then collected identical data from never-fluoridated Culemborg. DMFS rates initially increased in Tiel then dipped to 11% of baseline from 1968/69 to 1987/88 while never-fluoridated Culemborg's 15-year-olds had 72% less cavities over the same period, reports Caries Research (8).
In New York State, cavities and tooth loss are greater in fluoridated rather than in non-fluoridated counties (9). In fact, tooth decay crises exist in most, if not all, large fluoridated U.S. cities (10).
Sometimes stopping fluoridation has no effect as in Kuopio, Finland (11), and Durham, North Carolina (12).
Some countries show lower decay rates in less fluoridated villages when compared to higher fluoridated villages such as in Uganda (13, 14), the Sudan (15) and Ethiopia (15a).
In South Australia, dental examinations of 4800 ten- to fifteen-year-olds' permanent teeth reveal unexpected results - similar cavity rates whether they drink fluoridated water or not (16).
In the United States, despite living without fluoridated water, rural children's cavity rates equal those of urban children, who are more likely to drink fluoridated water, according to a large national government study of over 24,000 U.S. children (17).