In an advance toward solving a 50-year-old mystery, scientists are reporting new evidence on how the fluoride in drinking water, toothpastes, mouth rinses, and other oral-care products prevents tooth decay. Their report was published online on April 4, 2013 in the American Chemical Society journal Langumir. Dr. Karin Jacobs and colleagues at Saarland University in Germany explain that despite a half-century of scientific research, controversy still exists over exactly how fluoride compounds reduce the risk of tooth decay. Research established long ago that fluoride helps to harden the enamel coating that protects teeth from the acid produced by decay-causing bacteria. More recent studies have shown that fluoride penetrates into and hardens a much thinner layer of enamel than previously believed, lending credence to other theories about how fluoride works. The current report describes new evidence that fluoride also works by impacting the adhesive force of bacteria that stick to the teeth and produce the acid that causes cavities. The experiments — performed on artificial teeth (hydroxyapatite pellets) to enable high-precision analysis techniques — revealed that fluoride reduces the ability of decay-causing bacteria to stick, suggesting that, on teeth, it would be easier to wash away the bacteria by saliva, brushing, and other activity. [Press release] [Langmuir abstract]Login Or Register To Read Full Story