Children's pit and fissure sealing is a technique that can effectively enhance children's ability to resist dental caries during their tooth development. Specifically, a layer of polymer composite resin material is coated in the pit and fissure of children's teeth, and the liquid resin solidifies and hardens after entering the pit and fissure, forming a protective barrier, just like putting a protective coat on a defective tooth to protect the tooth from food and bacteria, thus enhancing the ability to resist dental caries.

The pit and fissure of each tooth is different in shape and depth, which is a suitable place for food residues to remain and bacteria to grow and reproduce. If the pit and fissure is deep, bacteria will use the sugar in the residual food to reproduce and grow in these hidden narrow ditches, and produce acidic substances during metabolism, which will corrode teeth and easily lead to dental caries, which is called pit and fissure caries in medicine. According to the data, more than 90% of the young people's dental caries occur in pit and fissure, so the risk of pit and fissure caries is great.

The main purpose of pit and fissure sealing in children is to prevent dental caries, so it is mainly aimed at the newly erupted permanent molars of children and adolescents. Six-year-old teeth are the most important teeth for chewing. Because it erupts early, it is easy to get caries (worm teeth) without protection, so it becomes the main object of pit and fissure sealing. Usually, six-year-old teeth erupt completely at the age of 7-8, which is the best age for closure.