Objective To explore the clinical application of ICON resin inffltration restoration combined with cold light whitening instrument in the restoration of dental ffuorosis and its inffuence on whitening effect. Methods A total of 80 patients who underwent restoration of dental fluorosis in our hospital from January 2023 to December 2025 were selected as the research subjects. According to the random number table method, they were divided into the control group and the observation group, with 40 patients in each group. The control group was treated with cold light tooth whitening instrument, and the observation group was treated with ICON resin inffltration restoration combined with cold light whitening instrument. The whitening effect, tooth sensitivity and lesion area were compared between the two groups. Results The total effective rate of the observation group (97.50%) was higher than that of the control group (85.00%) (P<0.05). There was no signiffcant difference in tooth sensitivity between the two groups (P>0.05). The lesion area of the two groups immediately and 12 weeks after treatment was smaller than that before treatment, and that of the observation group was smaller than that of the control group (P<0.05). Conclusion For patients undergoing restoration for dental ffuorosis, the combined application of ICON resin inffltration restoration and cold light whitening instrument can improve the whitening effect, without increasing tooth sensitivity, and effectively ameliorate dental lesions.