Children are in the special period of milk tooth replacement and permanent tooth eruption, which is a sensitive and high-risk group for oral diseases. This stage is also a critical period for acquiring oral hygiene knowledge and establishing correct behaviors. Giving timely and scientific guidance on oral health care for children and taking effective preventive and curative measures will have a positive impact on their oral health and general health throughout their lives. Then our hospital will also actively organize dental professionals in this activity, go deep into schools and communities, focusing on children, carry out various forms of health promotion, popularize oral health care knowledge, and guide the public to develop good oral health habits and medical behavior. This time, the central subsidies for local public health funds in the central and western regions of children’s oral disease comprehensive intervention pilot project areas at the same time to be combined with the national “Love Teeth Day” activities, and actively organize school-age children to consciously participate in oral health checkups and gutter closure, our hospital will be the designated specialist hospital for gutter closure in the Lianhu District, here We also hope and welcome our parents and friends to bring your children to the hospital to do preventive health care, we will certainly complete the task on time, quality and quantity, one, the sulcus caries affects children’s dental health. The sulcus of each tooth has different shapes and depths, which is a suitable place for bacteria to grow and breed. Therefore, the risk of caries is higher in deep sockets. Once the caries occurs, the damage can develop rapidly to the deep part, forming the cavity which is small in appearance but deep and big in reality, and the caries can eventually spread to the pulp (dental nerve), leading to pulp inflammation or apical inflammation, which will lead to tooth loss if not treated in time. The back teeth are responsible for the main chewing function, once lost, the chewing function will be greatly reduced, affecting the nutritional intake and growth and development. If we can effectively prevent and control the occurrence of sulcus caries, it can not only greatly reduce the level of caries in children and adolescents, but also reduce personal economic burden and social medical resources consumption. Secondly, fossa closure is an effective method to prevent children’s fossa caries. Vulcus closure is a method to prevent vulcus caries by applying the sealing material to the vulcus point gap on the occlusal surface and buccal and lingual surfaces of the crown without damaging the tooth body tissue to prevent the erosion of cariogenic bacteria and acidic metabolites to the tooth body. It is just like coating a layer of lacquer on the surface of wood products to prevent corrosion and insect decay, and coating rust-proof paint or spraying plastic to prevent rusting of iron products in daily life. This resin is non-toxic and harmless, not only does not affect the chewing function of people, but also can adapt to the environment of the mouth. Even if the socket sealant falls off, the resin protrusion that penetrates into the enamel has a protective effect on the teeth. The main application of the sealant is on the milk molars, permanent molars and permanent premolars. The best time to seal is when the crown is fully erupted and the caries has not yet occurred, generally at the age of 3-5 years for the milk molar, 6-8 years for the first permanent molar and 11-13 years for the second permanent molar. The sulcus of middle-aged and old people’s back teeth will gradually become shallow or disappear with the abrasion of chewing food, and some of them have already got caries after the susceptible period of sulcus caries, so there is no need to do sulcus closure again. Thirdly, the operation of fossa closure is safe and simple. Fossa closure is a painless, non-invasive, safe and simple caries prevention technique. It uses non-toxic sealing material, which is harmless to teeth, and even if the sealing material falls off and is swallowed, there is no adverse effect on human health. Children who receive the sealant do not feel any discomfort in the process of sealant, and the whole process is divided into 6 steps, which only takes about 10 minutes: 1. Removal of food debris and plaque on the dental surface. 2, acid etching. Treatment of the tooth surface with weak acid, to play a re-cleaning and facilitate the role of sealant adhesion. 3.Rinsing and drying. Rinse the weak acid left on the tooth surface, blow dry the tooth surface in a chalky state. 4.Application of sealant. Apply the sealant sequentially at the sulcus. 5.Curing. The sealant cures and hardens by visible light for about half a minute. 6.Check. Check the sealing effect. The sealant can be maintained on the tooth for several years. Just sealed teeth, avoid biting too hard and sticky food, such as chewing gum, bubble gum. After the closure, it is best to review once after 3-6 months, and then every year when the oral routine examination, at the same time check the closed teeth, if the sealant is found to fall off, timely to make up. Fourthly, the joint use of fluoride and sulcus sealant can prevent the occurrence of caries to the maximum extent. The caries can occur in different parts of teeth, the caries that occurs in the part of the fissure groove is called sulcus caries, the caries that occurs in the smooth surface is called smooth surface caries. The use of sulcus closure can prevent the occurrence of sulcus caries, but it has no preventive effect on the smooth surface and adjacent surface of teeth. Fluoride is a chemical caries prevention method, which can effectively prevent the occurrence of caries on smooth surface and adjacent surface of teeth by enhancing the anti-carious ability of teeth and promoting remineralization. Therefore, the combination of sulcus closure and fluoride can prevent both sulcus caries and smooth surface caries, and prevent the occurrence of caries to the maximum extent.