How does tooth decay form? After the teeth grow out, the bacteria in the mouth stick to the tooth surface and form plaque on the tooth surface together with the mucin in saliva. The bacteria metabolize and ferment in the plaque to produce various organic acids, which accumulate in the plaque. The effect of the acid in the plaque on the teeth is to dissolve the calcium off the tooth surface, and over time, the tooth surface at the decalcification area forms a depression. The uneven tooth surface is more likely to form the plaque, and the pit becomes deeper and deeper, that’s how the tooth caries is formed. The reason why children are easy to suffer from caries: Caries can happen to people of any age, but children are more likely to suffer from caries. 1984, the Ministry of Health and the national dental prevention group conducted the second epidemiological survey of caries, and the survey shows that the incidence of caries of 5-year-old children’s milk teeth is up to 76.6%, and the average caries is 4.48. It shows that children have a higher incidence of caries. Why children are especially prone to dental caries? This is because on one hand children love to eat soft food, such as all kinds of pastries, cookies, candies and other snacks, which have high sugar content and high viscosity and are not easy to be cleaned when they stick to the tooth surface, so it is easy to form plaque and become a breeding ground for bacteria, some children like to drink fruit juice and cola drinks, which have more sugar and high acidity, creating favorable conditions for the occurrence of dental caries. At the same time, children eat less cellulose food and cannot clean the tooth surface automatically through the frictional effect when chewing food. On the other hand, children’s teeth erupt from 6 months to 2.5 years old, and permanent teeth erupt from 6 years old to 12 years old to replace milk teeth. The milk molars, which are usually called big teeth, also have the characteristics of many sockets and gaps on the tooth surface and large contact area between adjacent teeth, which are the favorable conditions for children to be prone to caries. Especially, the thickness of hard tissue of milk teeth is only 2mm, so it is easy for caries to enter the deep layer of teeth, thus once caries occurs in milk teeth, the progress is very fast. In addition, the oral hygiene condition of children also has an important influence on the occurrence of dental caries. When children are very young, they can’t brush their teeth by themselves, but many parents are used to give their children a bottle of milk or some snacks before going to bed, without thinking that they should help children clean their teeth afterwards. In addition, children sleep more, and the secretion of saliva decreases during sleep, and the mouth is in a static state, which is not conducive to the cleaning of teeth, and all these increase the chance of tooth decay. Therefore, parents should patiently help their children clean their mouths every day from the time their milk teeth erupt. Parents should teach their children to brush their own teeth after they are 3 years old, and the good habit of brushing teeth every day is very important to prevent the occurrence of dental caries. The harm of milk teeth caries: Milk teeth caries can cause the loss of several teeth, change the occlusal relationship between upper and lower teeth, disrupt the function, and affect the development of jaw bone and face. The long-term chronic periapical lesion of milk teeth will affect the development of permanent tooth embryo and cause developmental disorder, and some of them will cause cyst of permanent tooth embryo, and permanent teeth cannot erupt normally. The crown of the baby tooth is destroyed, or the caries causes the baby tooth to fall out, so that the chewing force decreases and the chewing function is reduced. The broken crowns and roots can stimulate the soft tissues of the mouth to form ulcers. Between the decayed milk tooth and the adjacent permanent tooth, it is easy to accumulate food and good to develop caries. Promote bad oral habits. The affected child is often reluctant to use the affected tooth to chew food because of pain, and the affected jaw bone lacks physiological stimulation, and the development of both sides of the jaw bone will be asymmetrical after a long time. When multiple milk teeth are involved, the appetite will be reduced and the digestion will be poor, which will affect the growth and development of the whole body. Chronic periapical inflammation caused by tooth decay can be called a lesion, and when the body resistance decreases, the bacteria transfer to other parts of the body to cause disease, such as arthritis and nephritis. The caries of front teeth looks unsightly and affects the pronunciation. It can produce psychological pressure on children. Thus, it is important to protect the baby teeth. The prevention of children’s caries: we should start from the etiology, combine with the developmental characteristics of children and diet, hygiene habits, etc., and make a comprehensive analysis. Specific methods are summarized as follows: 1. Keep oral hygiene: brush teeth every morning and evening, rinse mouth after meal, and master the correct brushing method, it is appropriate to use the smooth brushing method. After the first milk teeth erupt, the mother should use sterilized wet gauze to clean the baby’s teeth. At the age of one to two years, parents can help brush the teeth with a fingertip toothbrush or a toddler toothbrush. From two and a half years old, the child can be taught the correct method of brushing teeth, and the child should brush teeth twice a day, once in the morning and once in the evening, and by six years old, the child can brush teeth by himself, but the parents should supervise. 2.Fluoride anti-caries use fluoride toothpaste, or use fluoride medicine coating in hospital. Because young children often can’t spit out the residual toothpaste well, the fluoride in the body will lead to fluorosis if accumulated too much, such as dental fluorosis and bone fluorosis. Therefore, children’s toothpaste with low fluoride concentration should be used before the age of 8. 3.Socket closure: For the narrow and deep sockets, using sockets sealant can effectively prevent the occurrence of sockets caries. The time of sealing for milk molar is appropriate at the age of 3~4 years old. The time of closing the first permanent molars should be 6~9 years old. 4.Limit the intake of sugar: eat less sweet food, avoid eating sweet food between meals (the rate of caries is higher if you eat sugar between meals), do not eat sweet food before going to bed, and wash your mouth after eating sugar or sweet food. 5.Dietary caries prevention: eat more fibrous food, appropriate amount of protein, vitamin A, D and calcium, phosphorus, etc., can improve the anti-caries of teeth to prevent the occurrence of caries. 6.Actively treat the caries that has occurred. 7.Regular checkup: Take your child to the hospital’s stomatology department for checkup regularly. Treatment of child caries: The treatment of cavity (hard tissue defect) already formed includes filling treatment and root canal treatment. If the cavity is not deep to the pulp and there is no symptom of pulp infection, it can be treated simply by filling. If the damage is deep to the pulp, root canal treatment must be performed. Therefore, children’s caries should be detected early and diagnosed early and treated early in order to reduce the pain of children’s caries and the cost of caries treatment.