Children’s sixth age teeth are not replaced and the first permanent molars may erupt in the distal molars at the age of 5-6 years. The permanent teeth are the second set of human teeth, which are kept in the mouth after replacing the milk teeth and will not be replaced. During this period, children’s oral hygiene is poor and they like to eat too sticky and sweet food, at the same time, the sulcus of the jaw surface of the sixth age teeth is deeper and there is a risk of forming caries. When the sixth age teeth are completely exposed in the oral cavity and reach the occlusal plane, the sulcus can be closed and the flowing resin can be applied to fill the jaw surface to reduce the occurrence of caries. If the caries damage has been formed on the jaw surface of the sixth age teeth, or there is a tendency of suspicious caries, the discolored tooth tissue can be grinded away in time, and the composite resin or silver amalgam can be filled.