Children’s teeth have holes that need to be filled, the details are as follows: 1, milk and permanent teeth replacement period: children are in the milk and permanent teeth replacement period, more scattered gaps in the dentition, often stagnant food debris triggered by caries, to repair cavities in a timely manner, to avoid caries expansion pain, affecting chewing and eating. 2, chronic apical periodontitis: milk teeth after chronic apical periodontitis, it will be stagnant in the dentition, hindering the smooth eruption of permanent teeth, resulting in The caries cavity will be formed in many teeth in the oral cavity, and the food residues will cause the cariogenic bacteria to rise, which will produce a cariogenic environment, and the newly erupted teeth will also form the caries cavity.3. Permanent teeth: the caries must be repaired as soon as possible after the caries, to avoid the rapid progress of caries to destroy the anatomical shape of the crown, to shorten the service life of the teeth, or to form the stumpy root of the crown of the permanent teeth.