Fluoride coating much thinner than thought (UPI)
Monday December 20th, 2010
SAARBRUCKEN, Germany, Dec. 17 (UPI) -- German researchers say fluoride's protective cavity shield on teeth is a 100 times thinner than previously thought.
[...] the researchers find this fluorapatite layer is only 6 nanometers thick -- much thinner than anyone had expected.
The researchers pointed out 10,000 of these layers would be needed to span the width of a human hair. They have suggested a layer this thin may be quickly worn away by ordinary chewing and question whether a layer this thin can shield teeth from decay or whether fluoride has some other unrecognized effect on tooth enamel.