Objective To explore the effect of nanocomposite resin on masticatory function in patients with anterior tooth defect. Methods A total of 86 patients with anterior tooth defect who received treatment in the Department of Stomatology, Fengxiang Traditional Chinese Medicine Hospital from June 2022 to June 2025 were selected as the research subjects, and they were divided into the control group and the observation group by the random number table method, with 43 patients in each group. The control group was restored with light-curing composite resin, and the observation group was restored with nanocomposite resin. The restoration effect, masticatory function, periodontal health indicators and aesthetic effect were compared between the two groups. Results The excellent and good rate of the observation group (97.67%) was higher than that of the control group (81.40%) (P<0.05). The occlusal force and masticatory efffciency of the observation group after 7 days of restoration were better than those of the control group (P<0.05). The periodontal health indicators of the observation group after 7 days of restoration were lower than those of the control group (P<0.05). The scores of each dimension of MC-PIDAQ in the observation group after 3 months of restoration were better than those of the control group (P<0.05). Conclusion For anterior tooth defect, nanocomposite resin can provide excellent restoration effect. It not only has a high excellent and good restoration rate, but also can comprehensively improve masticatory function, promote periodontal health, and achieve ideal aesthetic evaluation.