There are three main methods of cosmetic dentistry for discolored teeth: drug decolorization, photosensitive veneers, and porcelain crowns (porcelain veneers). Drug decolorization is mainly applied to the yellowing of teeth caused by the change of tooth quality with age, and it is less effective for the heavily colored tetracycline teeth and fluorosis teeth. Treatment should follow medical advice to avoid tooth allergy and other adverse reactions. Some decolorizers are inferior products, which should draw the attention of doctors and patients. The effect of cold light teeth whitening, which is currently used in large quantities, is questionable. Not only is the effect of teeth whitening average, but it is also easy to recur and cause great damage to teeth, so it is not recommended. Photosensitive veneers have short retention time, bad color, easy to fall off, easy to discolor, cause gum swelling, bleeding and other disadvantages, but they are still being carried out at home and abroad because of low price and little damage to teeth. If you do not grind the teeth and pay strict attention to the edge of the close and smooth, to avoid the irritation of the gums, or can be considered. Porcelain crowns are the most effective and longest holding method, mainly for moderate and severe tetracycline teeth and fluorosis. (Orthodontics or a combination of orthodontic and porcelain treatment should be preferred for reversed teeth.) It mainly has the following categories: ordinary porcelain: nickel-chromium alloy as the inner crown, currently the most popular and inexpensive in China. Shoulder porcelain is in the metal porcelain tooth neck with a special edge porcelain powder to improve accuracy, can avoid gum swelling, bruising. Price is only slightly higher than ordinary porcelain, performance and price is better. Precious metal porcelain is made of gold-platinum-palladium alloy as the inner crown and outer porcelain powder. Compared to ordinary porcelain, it has the advantages of beautiful color, strong adhesion and good biocompatibility. All-ceramic is the newest and most beautiful. The representative product is cast porcelain, with high-strength porcelain as the inner crown, and therefore good transparency. Its excellent optical properties, excellent biocompatibility, realistic color has made it the first choice of Europeans and Americans in the last decade or so. However, it is slightly lower strength, high technical requirements for doctors, there are also very high strength zirconia all-ceramic, representative products for Wol-Ceram, Cercon, etc., are more advanced technology. It should be noted that cosmetic restorations should preserve the pulp, i.e., the dental nerve, as much as possible to minimize damage to the tooth, which has been the consensus of most dentists at home and abroad. In addition, patients should not overly demand straighter teeth; mild misalignment can make the teeth more natural. Teeth that must be decontaminated should undergo root filling and thorough treatment.