We all know that fillings can effectively treat caries and other dental tissue loss diseases, some parents and friends are thinking that children’s milk teeth are going to be replaced anyway, no need to fill. In fact, this is wrong, milk teeth also need to be filled. So why is this? Local effects 1, leading to swelling and pain. Children due to imperfect nerve development, or caries fast development, most cases do not hurt, but parents are easy to neglect. 2, affect the chewing function, and even lead to partial chewing, partial side of the hypertrophy, the other side of the function of the waste. Affect the order and position of permanent teeth eruption. Permanent teeth are prone to early eruption, late eruption, blocked eruption and unevenness. After the caries of the adjacent surface of the milk teeth, the anterior and posterior diameter becomes shorter, and the posterior teeth are immediately shifted forward, leaving insufficient space for the permanent teeth embryo below, resulting in the permanent teeth erupting in a deviation from the normal position, or even blocked in the jawbone. It is one of the main reasons for uneven teeth. 4.Severe apical periodontitis of milk teeth, resulting in enamel underdevelopment of permanent teeth. 5, residual root, residual crown piercing the lip, cheek and tongue mucosa. 6.Impact on pronunciation and aesthetics. Systemic effects 1, most, serious caries affect chewing lead to children’s nutritional intake reduction, aggravate the burden on the digestive system, partiality, reduce body resistance. 2. Normal chewing stimulation is favorable to the development of brain and jawbone. 3.Become the focal tooth of systemic diseases.