Tooth bleaching is to use peroxide to penetrate into the enamel and dentin to carry out the redox reaction, so that the coloring molecules decompose into colorless substances to achieve the purpose of bleaching. Tooth bleaching can be applied to a wide range of tooth color abnormalities caused by hyperpigmentation, tobacco spots, wine spots, fluorosis, tetracycline teeth, dead pulp teeth, etc., which can be improved by bleaching. Tooth bleaching has the advantages of less damage to the teeth and quicker results, but bleaching cannot change the shape and position of the teeth. It is worth noting that tooth bleaching is not a permanent solution, the tooth color will return to different degrees after tooth bleaching, but the effect of tooth bleaching can be maintained at a stable level within 1-3 years, in addition, after the color of bleached teeth returns, the effect of bleaching again will be 5-7 times faster than the original. During the process of tooth bleaching, tooth sensitivity and soreness may occur, which is a normal phenomenon, and desensitizing toothpaste can be used to relieve tooth allergy. At present, our department carries out the safest home bleaching. The home bleaching method is that after the doctor makes plastic film braces for the patient, the patient carries the bleaching agent home and applies the bleaching agent to the tissue surface of the plastic film braces while sleeping at night, then puts it on the teeth and takes off the braces in the morning after waking up. A course of home bleaching takes about a week, and two courses of treatment can achieve better results for lighter discoloration, while the course of treatment required for heavier discoloration depends on the degree of staining.