Objective To explore the application effects of different restorative materials in children with tooth defect. Methods A total of 120 children with tooth defect admitted to the Fifth People's Hospital of Ningxia Hui Autonomous Region from April 2024 to August 2025 were selected as the research subjects, and they were divided into group A, group B and group C by the random number table method, with 40 children in each group. Group A was treated with composite resin fflling, group B was treated with glass ionomer cement fflling, and group C was treated with prefabricated metal crown restoration. The restoration effect, aesthetics, satisfaction and complication rate were compared among the three groups. Results There was no statistically signiffcant difference in the restoration effect among the three groups (P>0.05). The aesthetic score of group A after restoration was higher than that of group B and group C (P<0.05), and that of group B was higher than that of group C (P<0.05). The scores of restoration method, restoration effect, functional satisfaction and comfort satisfaction in group A were higher than those in group B and group C (P<0.05), and those in group B were higher than those in group C (P<0.05). There was no statistically signiffcant difference in the incidence of complications among the three groups (P>0.05). Conclusion The application of composite resin in the restoration of children's tooth defect can effectively improve the aesthetics and satisfaction of children while achieving good restoration effect and not increasing the risk of complications.