This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': 'The effects of amine fluoride on enamel solubility was first studied by- \nSelect and explain. \nA. Muhlemann, B. Lecompte, C. Brudevold, D. Issac', 'role': 'user'}, {'content': 'Answer: A \nExplanation: In 1957, Muhlemann and co-workers of the\xa0University of Zurich, first studied the effects of\xa0amine fluoride on enamel solubility in vitro.\xa0They found that, under the conditions of their\xa0study, certain organic fluorides were superior\xa0to inorganic fluorides in reducing enamel\xa0solubility. They attributed the improved effect\xa0to a combination of chemical protection\xa0afforded by the fluoride and physicochemical\xa0\nprotection due to the organic portion of the\xa0molecule.', 'role': 'assistant'}]