The incidence of dental caries, also called tooth decay, is a common disease in dentistry and a multifactorial disease, in which food residues are decomposed by bacteria, fermented and acid-producing and caries occurs in teeth. Many parents think that tooth decay is a minor disease, but this view is wrong. If caries is not intervened in time, it will combine with pulpitis, apical infection, periodontal abscess, alveolar abscess, and even cause tooth loss due to caries. Once the tooth is missing, it will also seriously affect the tooth alignment, facial development and pronunciation. In addition, some pathogenic bacteria in teeth can aggravate stomach disease, diabetes, cardiovascular disease, kidney disease and other diseases and complications, and become an important cause of many diseases with high mortality. Teeth, especially molars, have many fissures, which are uneven and act like a grinding disc, increasing the chewing area and increasing friction, which helps to chew the food fully. However, the fissures in these parts are deeper, easy to accumulate food residues, and not easy to remove, once the bacteria invade, it is easy to occur decay, and gradually damage the whole tooth. At present, the technique of fissure closure carried out in China is one of the most effective methods to prevent dental caries recommended by the World Health Organization to children all over the world. It is a kind of organic polymer resin material which is harmless to human body, coated in the sulcus of the biting surface of teeth, and after the material is cured, it can be retained in the sulcus for a long time, forming a protective barrier to isolate the erosion of bacteria and acid to teeth. Figuratively speaking, it is like applying a layer of paint to prevent iron products from rusting in daily life. Closure once can protect teeth from caries for 3 to 5 years. Vulcanization does not need to grind away the tooth tissue, it is painless and can be done in a short time. If tooth decay has already occurred, it is not suitable to do sulcus closure, and should be given treatment in time. The best time to do the closure is within six months of the eruption of new teeth, about 3-4 years old for milk molars, 6-7 years old for the first permanent molars, 11-13 years old for the second permanent molars and 9-13 years old for the bicuspids. Oral Health Tips The sign of successful closure is the presence of the sealant intact. Regular checkups are needed after the sealant is in place, and if it wears or falls out, it can be repaired or redone in the hospital; if you find that the closed teeth have overbite or pain when eating within a few days after the procedure, you should follow up promptly.