Objective: To explore the impact of modified oral cleaning and nursing on tooth surface roughness and smile confidence in patients who have undergone orthodontic fixed appliance treatment.Methods: A total of 102 patients who completed orthodontic fixed appliance treatment in our hospital between December 2024 and December 2025 were enrolled as subjects. They were divided into a control group and an experimental group using the random number table method. The control group received routine oral cleaning and nursing, while the experimental group was given modified oral cleaning and nursing. The differences in tooth surface roughness, smile confidence, oral plaque index, and incidence of adverse events between the two groups were analyzed.Results: At 4 weeks and 8 weeks after intervention, the tooth surface roughness of the experimental group was significantly better than that of the control group (P < 0.05). The experimental group also showed higher scores in smile confidence dimensions including appearance satisfaction, social willingness, and self-identity compared with the control group (P < 0.05). Additionally, the oral plaque index of the experimental group was lower than that of the control group after intervention (P < 0.05). The incidence of cleaning-related adverse events such as tooth sensitivity, gingival bleeding, and tongue surface injury in the experimental group was significantly lower than in the control group (P < 0.05).Conclusion: Modified oral cleaning and nursing for patients after orthodontic fixed appliance treatment can effectively reduce tooth surface roughness, improve smile confidence, lower oral plaque index, and decrease the incidence of cleaning-related adverse events.