There are two main means to turn yellow teeth white, including scaling and polishing of the tooth surface, and you can also go to the hospital for cold light whitening treatment. Scaling and polishing are mainly seen in patients with yellow teeth caused by exogenous staining. Some patients have poor oral hygiene for a long time, or prefer to drink tea, coffee or smoke, and the yellowish-brown pigment and tartar will accumulate on the teeth of such people, thus making the teeth unattractive. In this case, you need to go to the hospital to clean your teeth and use ultrasonic scaling to completely remove the pigment and tartar deposited on the tooth surface and restore the original face of your teeth, so as to achieve the effect of whitening your teeth. Cold light whitening technology is mainly used for teeth yellowing due to endogenous coloring, such as those born with dull yellow teeth, or those with increasingly yellow teeth as they age, or those born with fluorosis or tetracycline teeth, which cannot be whitened by brushing and scaling, and need to go to the hospital for cold light whitening treatment to improve the shade of the teeth and make them White.