What for should one bleach his teeth?
Dental bleaching conducted by a professional dentist differs from bleaching with the help of toothpaste mostly in the substances used for it. Professionals use completely different substances for dental bleaching. Bleaching toothpastes mostly contain abrasive components so when you clean your teeth you grind the dental enamel. Trying too hard you can even destroy the dental enamel. Moreover, the effect of such toothpastes is barely visible.
Professional dentists use completely different substances for dental bleaching. Most of them contain hydrogen peroxide. This is an absolutely different method of dental bleaching. No enamel destruction takes place here. Professional bleaching can radically change the color of your teeth. It will take not so much time but the effect will last for years. Dark-brown teeth will easily become excitingly white. Such effect can never be achieved with the help of a toothpaste even if you use it for years. Still, the dental enamel will be destroyed thats for sure.
There is also a logical question: why do toothpastes not contain hydrogen peroxide.
Then their bleaching effect would be more obvious. The answer is simple - hydrogen peroxide is a powerful substance and in case it contacts your gums, stomach, or throat the effect will be not a pleasant one. People use toothpastes without doctors control. That is why the law prohibits using powerful substances in such toothpastes. They can be used only under doctor`s supervision.
Lately you could have seen numerous ads of toothpastes containing hydrogen peroxide. Do not believe them. It is just a trick. Such toothpastes can possibly contain hydrogen peroxide but in extremely small doses. They do not cause negative effects but no bleaching effect should be expected as well.