A pair of bright white teeth and a bright smile often swept away the gloomy mood and regained self-confidence. More and more people realize that beautiful and white teeth play a very important role in life, so various treatment programs for the purpose of whitening teeth came into being. Most of the whitening toothpastes, toothpastes, etc. currently on the market contain a certain amount of hydrogen peroxide, which is used for tooth bleaching. But this ingredient is likely to damage the gums and cause damage such as chemical burns to the mouth. The American Dental Association has warned that the content of hydrogen peroxide in teeth whitening products should not exceed 6%. When it reaches 15% – 35%, it is easy to cause tooth sensitivity, stimulate oral soft tissue or gums, etc., especially for individual tooth enamel development Bad, cracked, and moderately worn teeth do more damage. Hydrogen peroxide is a chemical substance and should not be used excessively for a long time. Children and pregnant women are best banned. In addition, the oxidant will penetrate the surface of the tooth and enter the inner tissue of the tooth. Once the calcium deposition is uneven, the reaction with the oxidant will be uneven, thereby bleaching the “flower” teeth. For the yellowing and blackening of teeth caused by pigment attachment, you can choose whitening stickers, tooth powder, etc. These products are mainly used to clean teeth, but you must choose a regular brand when purchasing. Many whitening products printed in Japanese and Korean on the Internet have unknown ingredients and must be used with caution. The frequency of use should not be too high, no more than 2 times a day, each time for up to 30 minutes. After use, rinse your mouth and wipe in time to remove the residual gel on the teeth. Those with sensitive teeth should reduce the dosage and use it for no more than 3 consecutive days. In the event of gum burns, throat blistering and ulcers, tooth sensitivity, soft tissue tingling, etc., stop using it immediately and go to the hospital for treatment. For exogenous teeth yellowing caused by drinking coffee and beverages, lemon juice is also a good way to whiten teeth. Lemon has strong cleaning power and whitening effect, and contains vitamin C, which can strengthen the root of the tooth. After brushing your teeth every night, wipe with some lemon juice on gauze, and your teeth will become white and bright. Professional cleaning and polishing can also be done once a year.