The smoke spots formed by long-term smoking will make the teeth yellow, so it is necessary to carry out thorough periodontal scaling to remove dental calculus, plaque and smoke spots. When the pigmentation is serious, you can whiten your teeth by sandblasting, but only by quitting smoking can you avoid the re-formation of pigmentation spots. In addition, cold light tooth whitening method can effectively whiten middle and low-grade black teeth. The effect of cold light tooth whitening method can improve the level of 5- 14 vitamine, and the operation process only takes 30 minutes without side effects, and the whitening effect can last for more than two years.