There are two main methods to whiten yellow teeth: first, ultrasonic cleaning treatment; second, cold light whitening treatment. Ultrasonic cleaning treatment is mainly for yellowing and blackening of teeth caused by exogenous staining of teeth, for example, people who smoke and drink strong tea will deposit tobacco and tea stains on their teeth, this pigmentation will make the teeth yellow and unattractive, and ultrasonic cleaning method is needed to completely remove the pigment and tartar on the teeth, making the teeth clean. If you are born with yellow teeth, or have tetracycline, dental fluorosis, or increasingly yellow teeth as you age. In this case it is necessary to do cold light whitening treatment, using the method of cold light whitening can neutralize the pigment in the dentin to enhance the shade of the teeth and make them white. Alternatively, porcelain veneers can be made on the surface of the teeth to restore the shape and color of the teeth.