Teeth whitening is harmful to the health of teeth. 1. If the patient uses bleaching agent to whiten, because bleaching agent contains peroxide, so that the use of the teeth will lead to very sensitive, the teeth will meet the wind cold, in drinking cold water, brushing teeth, and as soon as you touch the root surface of the teeth, you will feel so acidic. 2. If the patient is to use veneers to whiten, due to the need for dental preparation on the lip side of the teeth, which will lose part of the patient’s natural tooth tissue, there is a certain degree of harm to the teeth. 3. If the teeth are whitened with all-ceramic restorations, due to the need to first grind the teeth as a whole, this will cause irreversible damage to the teeth, and the teeth will be more fragile after grinding. It is recommended that patients who want teeth whitening, should be carried out under the guidance of the doctor, before proceeding to understand the whitening will have any adverse reactions, and then determine whether to teeth whitening.