Objective To explore the effect of fragment reattachment restoration on dental aesthetics and masticatory function in patients with crown fracture of young permanent teeth. Methods A total of 90 patients with crown fracture of young permanent teeth admitted to Suzhou Wuzhong People's Hospital from January to December 2023 were selected, and they were divided into the control group and the observation group by the random number table method, with 45 patients in each group. The control group received direct composite resin layering restoration, and the observation group received fragment reattachment restoration. The restoration success rate, dental aesthetics and masticatory function were compared between the two groups. Results There was no statistically significant difference in the restoration success rate between the two groups (P >0.05). The excellent and good rates of color matching and morphological aesthetics in the observation group after restoration were higher than those in the control group (P <0.05), but there was no statistically significant difference in the excellent and good rate of surface gloss between the two groups (P >0.05). The absorbance value of the observation group at 12 months after operation was higher than that of the control group (P <0.05). Conclusion For crown fracture of young permanent teeth, fragment reattachment can achieve a high restoration success rate. This method can not only effectively restore the natural shape and aesthetics of teeth, but also reconstruct their masticatory function, showing good comprehensive efficacy and biological advantages.