Cold light whitening is a technique to make teeth whiter. What kind of people are suitable for cold light whitening, I. The best effect of cold light whitening is caused by stained teeth such as tobacco stains, tea stains, coffee and cola. Second, moderate and mild tetracycline teeth, fluorosis, or other unknown factors caused by discolored teeth. Third, natural yellow teeth, also have certain effect. What kind of people can not do cold light whitening: 1, there are cavities, need to fill the teeth first, especially the defective, serious decay, or when the whitening agent touches the decayed place will be very painful, but also mistaken for whitening agent damage to the teeth. 2, pregnant women can not do. 3, periodontal disease is very serious, must first solve the periodontal problem. 4, have done porcelain veneers, or replaced the dentures, for these artificial materials whitening can not play The effect. There is no harm in cold light whitening teeth, the regular cold light whitening will not harm the teeth, but after the use of whitening agent oxidation, there will be some light demineralization on the surface of the teeth, after a period of time will automatically repair.