Objective To screen the better anti-fluorine microelement through adding iodine, molybdenum，selenium, magnesium and boron in feed and observing the mitigatory degree of dental fluorosis. Methods 170 male ICR mices were randomly separated to 17 groups. The blank group drank the distilled water. Fluorine group drank the distilled water containing sodium fluoride 110 mg·L-1. Both of them were common feed. Sodium fluoride was also given to mice in drinking water in 15 microelement groups. Kalium iodidum were added into feed with the dosage based on the 25%, 50%, 75% of compound LD50. Sodium molybdatesodium, sodium selenite, sodium tetraborate, magnesium sulfate were added into feed in the same way. The growth rate of body weight and tooth length, formative time of dental fluorosis, formative grade and final grade of dental fluorosis were observed. Results All of the five microelements can prevent the dental fluorosis in varying degrees. MgSO4 and Na2B4O7 with the dosage of 25% compound LD50 in feed show better preventive effect than others. Conclusion Magnesium and boron are potenial microelements that has anti-fluorine effect.
