Baby teeth yellow brush not clean may be caused by dental calculus, enamel underdevelopment, drug factors, food factors, can be improved by teaching children the correct way to brush, resin fillings and other methods. 1. Calculus: If the baby has calculus, the baby should be taught the correct way of brushing, and go to the hospital for scaling in time. 2. Enamel hypoplasia: when the baby has enamel hypoplasia will lead to yellow teeth, you need to go to the hospital regularly for review, usually pay attention to maintain oral hygiene, if there is a defect, you can go to the hospital for resin filling to maintain the beauty. 3. Drugs: If the baby uses tetracycline drugs such as gentamycin, it will lead to yellow teeth. After taking the drugs, you should keep clean and brush your teeth in the morning and evening to promote the beauty and health of the teeth. 4. Food factors: eat less coloring food, such as Coca-Cola. Baby teeth yellow brush has not been improved, it is recommended to consult a doctor in time, with the help of a clear cause, and targeted treatment or treatment.