MEDICINE

Viewpoint: Yes, the evidence is clear that significant concentrations of fluoride in drinking water cause harm to humans.

Viewpoint: No, the addition of small amounts of fluoride to drinking water does not cause significant harm to humans and provides several benefits.

Throughout history, dental caries—that is, decay of the teeth—has been the principal problem of dentistry. During the 1880s, Willoughby D. Miller, a student of the great German bacteriologist Robert Koch, showed that microorganisms are involved in the development of dental caries. Miller's findings were published in his book Microorganisms of the Human Mouth (1890). Following the path established by Miller, J. Leon Williams then demonstrated that bacteria in dental plaque produce the acid that attacks tooth enamel. Williams believed that good...