The sealing material used for fossa closure is called fossa sealant, which is cured and adheres closely to the wall of the fossa, and has a certain resistance to chewing pressure, which is not harmful to eating, and the fossa sealant is non-toxic after curing. The sealant can generally be retained for a long time. It is better to do a review once in 3-6 months after just doing the sealing, and when doing the oral routine examination every year in the future, the closed teeth should be examined at the same time, so as to find out whether there is any sealant loss in time, so as to make up for it in time. The principle of the prevention of sulcus caries is to fill the sulcus of the teeth with polymer material to make the tooth surface smooth and easy to clean, on the one hand, after the sulcus is closed, the original bacteria in the sulcus are cut off from the source of nutrition and gradually die; on the other hand, the cariogenic bacteria outside cannot enter again, so as to achieve the purpose of preventing sulcus caries. Role The biting surface (the side where food is chewed) of the large teeth at the back of each person’s mouth is uneven, and the recessed area is called the sulcus. If the development is not good, these grooves are very deep, food and bacteria are embedded in them, and it is easy to occur tooth decay (also called “worm teeth”, “tooth decay”), which is medically called as sulcus caries. According to the oral epidemiological survey, more than 90% of the caries of our teenagers occur in the sulcus area. “It is the permanent molar with the earliest eruption time, and its chewing function is the most powerful, and it is also the most prone to caries, even causing premature loss, so it is important to protect the first permanent molar of children. Therefore, it is important to protect the first permanent molar of children. Indications There are many factors involved in deciding whether or not to do sulcus closure, the most important of which is the appearance and evaluation of the sulcus. 1.Deep sockets, especially those that can catch the probe (including suspicious caries). 2.The patient’s other teeth, especially the opposite side of the same name tooth has caries or has the tendency to have caries. The best time The best time to close the sulcus is when the tooth is completely erupted and the caries has not occurred yet. 1.After children’s teeth erupted and reached the occlusal plane, it is suitable to make sulcus closure, usually within 4 years of eruption. 2.Milk molar is 3-4 years old, the first permanent molar is 6-7 years old, the second permanent molar is 11-13 years old, and the bicuspid is 9-13 years old. 3.For the disabled children with poor oral hygiene, although they are older or the teeth erupted from the mouth for a longer time, the age of fossa closure can be considered to be relaxed. Non-indications 1.Teeth that have already suffered from caries or have been filled. 2.The teeth have not yet erupted completely, and part of the occlusal surface is covered by gums. 3.No deep sulcus gap on the occlusal surface, good self-cleaning effect. 4.Children are not cooperative and cannot cooperate with normal operation. Generally speaking, middle-aged and old people have already passed the susceptible period of sulcus caries, and some of them have already got caries. At the same time, the sulcus of posterior teeth gradually becomes shallow or disappears with the abrasion of chewing food, so it is generally unnecessary to do sulcus closure again.