The effects of amine fluoride on enamel solubility was first studied by-

In 1957, Muhlemann and co-workers of the University of Zurich, first studied the effects of amine fluoride on enamel solubility in vitro. They found that, under the conditions of their study, certain organic fluorides were superior to inorganic fluorides in reducing enamel solubility. They attributed the improved effect to a combination of chemical protection afforded by the fluoride and physicochemical  protection due to the organic portion of the molecule.