Everybody wants white teeth because they bring along a beautiful smile that can make the difference between failure and success. But white teeth are very rare to find. Why? Because of our life stile: we like to smoke or to drink a good glass of red whine a cup of coffee or tea , to eat various synthetic foods that contains various colorants. All of these will surly stain the surface of your teeth.

Unfortunately there are more causes beside our life style that can rub us from a beautiful white smile:

- it is also possible to have stains that are inside the tooth. These are called intrinsic stains. For example, intrinsic stains can be caused by exposure to too much fluoride as a child while teeth are developing.

- Other causes include tetracycline antibiotics taken during the second half of pregnancy or given to children 8 years old or younger when the teeth are still developing.

You surely ask yourself why and how various foods and drinks affect our teeth. The problem is that each tooth presents an outer layer called enamel that contains little holes named pores. These pores can contain stains.

So, every day, a thin coating forms on your teeth and it picks up stains.

The solution for this problem is known by every dentist: tooth whitening.

Tooth whitening is a procedure that lightens teeth and helps to remove stains and discoloration. Whitening is among the most popular cosmetic dental procedures because it can significantly improve the appearance of your teeth at much less cost and inconvenience than other techniques. This process can by applied with some basic rules:

- Cavities need to be treated before teeth are whitened because the whitening solution can penetrate decay and reach inner areas of the tooth, which can cause sensitivity.

- Also, whitening will not work on exposed tooth roots, because roots do not have an enamel layer. Receding gums can cause roots to become exposed.

- Whitening also does not work on crowns or veneers.

Even with those rules this procedure is available to everyone and it can be done even at home!

The other way is in a dentist office.

For in-office whitening, your dentist probably will photograph your teeth, which will help him or her to monitor how the treatment is progressing. Whitening in the office may involve two to six visits of approximately 45 minutes each. He or she also will examine your teeth and ask you questions to determine the type and severity of staining. When the examination is complete, the dentist or a dental hygienist will clean your teeth. Once this is completed, the whitening procedure begins.

For whitening at home, your dentist will direct you to use custom trays that are made in the dental office and fit your teeth precisely. Home whitening usually takes two to three weeks. Over-the-counter kits also are widely available for home use. You should talk to your dentist about using these products, and use them according to directions to avoid overuse and possible damage to your teeth and mouth.