With the development of the times and the advancement of society, the scope of modern cosmetology is expanding and has extended from outside the body to inside the body, and teeth whitening is one example. Tooth whitening methods are constantly improving. Previous whitening methods each had their own shortcomings, and cold light whitening is the result of timely technological advances. The most common tooth coloring are internal tooth coloring (fluorosis, tetracycline teeth), tooth surface coloring, tooth decay, age-related discoloration, etc. Factors of yellowing teeth and whitening methods A. What is cosmetic dentistry? Because of the prevalence of beauty in recent years, many people pay great attention to whether their external appearance is pleasing to the eye, and because of the beauty of the teeth, it will directly reflect on their “face”, a mouth of yellow teeth will affect the perception of others. And have a mouthful of white teeth, in addition to having health, but also let you win more good opportunities! Why do I still have yellow teeth even though I have a dental cleaning every six months? Scaling is to remove the calculus in your mouth, and can not remove the staining on your teeth or change the color of your teeth, to remove the staining or make teeth white need to go through sandblasting, whitening or veneers. Third, yellowing teeth factors are 1, improper brushing habits; 2, long-term intake of dark food or drinks; 3, smoking; 4, tooth decay or fillings; 5, drugs caused by; 6, natural aging. Four, sandblasting whitening Acquired tooth staining, if only on the surface of the teeth, the physician will usually recommend the use of. Sandblasting whitening or using abrasives to brighten teeth directly to remove tooth staining, both use a very fine powder, but in sandblasting whitening machine, the powder of aluminum oxide is sprayed out to the tooth surface through the sandblasting machine at high pressure to remove the staining adsorbed on the outer surface of the teeth, so even in the very small places such as the crevices of the teeth can still be removed. Sandblasting is not sand, but the soda powder ingredient with particulate particles with mouthwash to rinse the dirt attached to the surface of the teeth Many people do not know that a layer of dirt on the surface of the teeth is not simply not clean brushing, but more because of the appearance of the teeth due to food coloring, but sandblasting is not permanent, you can repeat sandblasting, or regular sandblasting to maintain the beauty of the teeth in the mouth. Five, cold light whitening will sink in the enamel pigment, using whitening gel with 400 ~ 500 nano wavelength blue light source catalytic effect, the teeth on the pigment oxidation decomposition, so that the teeth become white. The operation process only takes 30 to 40 minutes, due to the use of low-temperature cold light, completely avoid the operation process will be discomfort to the dental nerve, in the hydrophilic drug and completely do not touch the gums in the treatment process, the tooth structure and x quality will not cause harm. Porcelain veneers Porcelain veneers are a very thin porcelain or plastic veneer, an alternative to braces, specially shaped and glued to the incisors, and may require local anesthesia during the process. Porcelain veneers can be used to improve the color, shape, and position of teeth or to restore integrity to chipped incisors, and can also be used for patients with large gaps that are not suitable for orthodontics or for patients whose teeth are not growing in the correct position. Unlike braces, porcelain veneers do not require the removal of much of the outer layer of the tooth, and are strong and durable, lasting ten to fifteen years in well maintained condition.