Objective To explore the effect of minimally invasive crown lengthening surgery combined with nano-resin on dental aesthetics and periodontal indexes in patients with subgingival wedge-shaped defect. Methods A total of 114 patients with subgingival wedge-shaped defect admitted to the Department of Stomatology, Beijing Nuclear Industry Hospital from January to December 2024 were selected, and they were divided into the control group (57 patients) and the observation group (57 patients) by the random number table method. The control group was treated with conventional crown lengthening surgery combined with nano-resin restoration, and the observation group was treated with minimally invasive crown lengthening surgery combined with nano-resin restoration. The restoration effect, dental aesthetics and periodontal indexes were compared between the two groups. Results The total effective rate of restoration in the observation group (94.74%) was higher than that in the control group (80.70%) (P <0.05). The excellent and good rate of dental aesthetics in the observation group was 89.47%, which was higher than 77.19% in the control group (P <0.05). The PD, CAL, BI and MOB in the two groups at 6 months after operation were lower than those before operation, and those in the observation group were lower than those in the control group (P <0.05). Conclusion Minimally invasive crown lengthening surgery combined with nano-resin has a good therapeutic effect on subgingival wedge-shaped defect, which can improve dental aesthetics and periodontal indexes.