First, we will introduce tetracycline teeth, which are endogenously stained teeth caused by tetracycline drugs taken during tooth development. The most susceptible period for deciduous and permanent teeth is from the fourth month of fetal life to about seven years of age after birth. The main manifestation of tetracycline teeth is tooth discoloration, which is classified into 3 degrees of discoloration: Mild: teeth are uniformly creamy yellow or light yellow. Moderate: teeth are light gray or yellowish brown. Severe: teeth are yellowish brown, brownish brown, gray, or black in varying shades. Depending on the classification of tetracycline teeth, the treatment varies: Mild staining can be left untreated. For moderate and severe tetracycline teeth, there are mainly the following treatment methods: 1, internal bleaching method: the principle of this method is to place the bleaching solution inside the tooth (the tooth itself is a cavity structure, the cavity is the space occupied by the dental nerve, science called the pulp chamber), from the inside out to play a bleaching effect, so that the pigment can be more thoroughly removed from the deeper layers of the hard tissue of the teeth, to achieve the effect of making the teeth white. However, this method is generally only applicable to the dead pulp teeth, if the living pulp teeth need to first pulp treatment (i.e. nerve killing), which is more than worth the loss. 2.Resin veneer: This method is to cover the color of the tooth itself by applying a layer of resin material similar to the color of normal teeth on the outer surface of the tooth, which is more effective in the short term. The disadvantage is that because the resin microstructure is honeycomb microporous, easily colored by food pigment, so generally about 3-4 years need to be re-treated. 3, porcelain veneers: If the teeth do not have large defects, but only poor color, you can take this method. It is through the tooth lip side (towards the outside of the side) of the outer surface of the uniform grinding away a layer of dental porcelain material to reshape the tooth shape and color, because you can precisely control the tooth color index, so the cosmetic effect is better, wear resistance and teeth similar. The disadvantage is more brittle, easy to disintegrate porcelain when subjected to excessive external force; cutting and biting hard objects may fall off. 4, all-ceramic crown: the outer surface of the tooth evenly abraded layer, with the above material will cover the entire tooth, restore the tooth shape, strength and beauty. The disadvantage is that the amount of abraded tooth tissue is large, there is a risk of pulp penetration, most suitable for patients with defects in the tooth itself or patients who do not have the conditions for veneer restoration. 5, porcelain full crown: porcelain full crown and full porcelain crown is the biggest difference is porcelain full crown inside a layer of metal crown. Due to the presence of metal crowns, strength is higher than porcelain veneers and all-porcelain crowns, the disadvantage is that the base metal crowns will be vaguely transparent metal color (precious metal crowns can generally avoid color problems). In addition, there are several methods, but also belong to the teeth whitening methods, Ontario introduced: 1, laser whitening: it is the use of higher concentrations of bleaching agents (such as hydrogen peroxide), with the appropriate laser dose, catalyze and increase, accelerate the bleaching effect of peroxide, and selective action on the pigment particles deposited on the teeth, to achieve bleaching effect; the tooth structure of those light-absorbing macromolecules broken into small The effect of the laser is to break the light-absorbing macromolecules in the tooth structure into small molecules, so that they no longer absorb light, and to achieve a safe whitening effect. At the same time, the appropriate dose of laser irradiation can close the dentin tubules, reduce the permeability of dentin and reduce the symptoms of dentin sensitivity in the process of tooth bleaching. 2, cold light whitening: cold light whitening technology is a popular tooth whitening technology in Europe and America in recent years. It first coats the teeth with a layer of whitening agent, and then uses low-temperature cold laser to decolorize and restore the teeth, thus removing the tooth surface to achieve whitening effect. The whole whitening process takes only 30 minutes and the whitening effect can be maintained for about 2 years. If you can reduce or avoid eating pigmented substances after the operation, the decoloration effect can be maintained for 6-8 years for light and moderately stained teeth. More than two million people worldwide have received Beyond Cold Light Teeth Whitening treatment, therefore, it is recognized as a tooth whitening technology with rapid and long-lasting results. It is generally considered that cold light whitening is suitable for mild and moderate tetracycline teeth. In conclusion, if the patient has severe tetracycline teeth, it is recommended to take crown restoration, and if it is mild or moderate, you can try to take other methods mentioned above. Finally, although there are various methods available, it is recommended that you first go to a specialist dental unit for a thorough examination of the restorative unit, so that the doctor can develop the most suitable treatment plan for you according to your actual situation and ask about the charges for the whole course of treatment before you receive the treatment.