It is wrong to think that the decayed milk teeth do not need to be treated, and it should be found and treated as early as possible. Once the decay of baby teeth, the cavity will easily retain the food, and the food fermentation and acid production will speed up the destruction of teeth. When the cavity is deep to the pulp, cold, hot, sour and sweet stimulation will cause pain to the children, and if the food enters the deep cavity, it will produce severe pain. Toothache will not only prevent children from eating normally and affect their intake of sufficient nutrition, but also cause lateral chewing and lead to asymmetric facial development. The rapid development of lesions in baby teeth can quickly lead to apical inflammation and bone destruction, and in severe cases, the lesions can even affect the permanent tooth germ. Premature loss of baby teeth will also cause misaligned eruption or ambulatory blockage of permanent teeth, resulting in uneven tooth alignment. Therefore, the decayed milk teeth should be treated as early as possible. Young children start to replace their teeth at the age of 6, and it takes more than 6 years until the whole mouth is replaced at the age of 12, if they suffer from tooth decay at the age of 4 or 5, the long time decay may cause lesions. Some parents find it strange that their children insist on brushing their teeth and seldom eat sweets, but many carious teeth are detected. Some parents also let their children develop the bad habit of sleeping with pacifier in order to induce infants to sleep. The pacifier is attached to the incisors, causing the incisors to be decayed soon, and this kind of caries is also called “bottle caries”. Experts suggest that because the development of decay of milk teeth is fast and the conscious symptoms are not as obvious as those of permanent teeth, parents should pay more attention to the dental health of infants and children, so that they will not go to the clinic only when it develops into endodontic disease or periapical disease, which affects the feeding of the affected children.