X-Ray Diffraction Analyses of the Reactions Between Intact and Powdered Enamel and Several Fluoride Solutions

The X-ray diffraction patterns of intact enamel treated with various fluoride solutions showed essentially no change in the crystalline structure of hydroxyapatite. The reaction between powdered enamel of various particle size and fluoride solutions showed a predominance of calcium fluoride formation. The substitution of F for OH ions in hydroxyapatite was not detected in the formation of fluorapatite under the experimental conditions.