Yellowing of the teeth in the body is usually caused by poor diet and hygiene habits, long-term drug effects, and aging of the teeth. When yellowing of teeth occurs, it is recommended to recover through tooth powder scaling, ultrasonic scaling and sexual tooth bleaching and laser teeth whitening. 1.Tooth powder scaling: This method is suitable for patients with relatively light pigmentation, and can be purchased from pharmacies and operated according to the instructions. 2.Ultrasonic scaling: It is the most widespread way of scaling teeth, mainly for the buildup of plaque caused by dental calculus. This method can remove the plaque and bacteria from the tooth surface, so that the teeth receive a white effect. 3.Active tooth bleaching: This method is very simple and usually involves the use of 10% hydrogen peroxide carbonate set on the teeth. With the action of the drug, the color of the teeth will be slowly restored, but this method of treatment is longer, about half a month to receive the effect of white teeth. And this drug will cause some damage to the teeth, it is recommended to use under the guidance of a doctor. 4.Laser teeth whitening: This method usually uses a higher concentration of bleaching agent for bleaching, which can effectively achieve the whitening effect, and it takes about three hours for a course of treatment. Each tooth whitening method has its pros and cons, so it is recommended to choose according to the patient’s own needs.