Abstract
Numerous literature sources reveal evidence that fluoride affects the activities of numerous enzymes in vitro as well as in vivo. Millions of people live in endemic fluoride areas with a severe public health problem. A plethora of data suggest that fluoride should be recognized as a developmental neurotoxicant for humans. The use of water fluoridation for the prevention of dental caries has increased the concern about adverse fluoride effects. The fluoride concentration at which a reduction in dental caries is expected is close to the level which might cause chronic pathological effects. We comment on how some of the conclusions of the recent review by Guth et al., published in Archives of Toxicology, are the emerging paradoxes in fluoride research. We show that fluoride has pluripotent effects, which might contribute to unexpected epidemics in the future.