Teeth whitening is becoming an increasingly popular cosmetic "treatment". Who doesn't want a winning smile? ... here is an interesting article for your reading (taken from Wikipedia):
THANK YOU TO WIKIPEDIA FOR SUCH A PRECISED WRITE-UP:
Dental bleaching, also known as tooth whitening, is a common procedure in general dentistry but most especially in the field of cosmetic dentistry. A child's deciduous teeth are generally whiter than the adult teeth that follow. As a person ages the adult teeth often become darker due to changes in the mineral structure of the tooth, as the enamel becomes less porous. Teeth can also become stained by bacterial pigments, foodstuffs and tobacco. Certain antibiotic medications (like tetracycline) can also lead to teeth stains or a reduction in the brilliance of the enamel.
There are two methods to whiten teeth: bleaching gel and laser bleaching. Traditionally, at-home whitening is done with bleaching gel which is applied to the teeth using thin guard trays. Oxidizing agents such as hydrogen peroxide or carbamide peroxide are utilized to lighten the shade of the tooth. The oxidizing agent penetrates the porosities in the rod-like crystal structure of enamel and oxidizes interprismatic stain deposits; over a period of time, the dentin layer, lying underneath the enamel, is also bleached. Laser bleaching utilizes light energy to accelerate the process of bleaching in a dental office. The effects of bleaching can last for several months, but may vary depending on the lifestyle of the patient. Factors which will decrease whitening include smoking and the ingestion of dark colored liquids like coffee, tea and red wine.Internal staining of dentin can discolor the teeth from inside out. Internal bleaching can remedy this. If heavy staining or tetracycline damage is present on a patient's teeth, and whitening is ineffective, there are other methods of whitening teeth. Bonding, when a thin coating of composite material is applied to the front of a person's teeth and then cured with a laser can be performed to mask the staining. A veneer can also mask tooth discoloration