Teeth whitening gel is characterized by rapid, simple, practical, safe, you just need continuously use with teeth whitening light 3 to 5 times, each time 15 minutes, when in use you can still work, just talking is a little bit limited. The main principle of whitening is oxidizing reaction, when hydrogen peroxide in contact with the tooth surface, it forms free root weight with huge oxidability, as hydrogen peroxide is similar to water, it can be easily absorbed into the tooth enamel to dentin then oxidize the pigment in teeth.