Our teeth can discolor through the years as our enamel wears down. The wearing down of enamel allows dentin, a yellow color substance that makes the core of our teeth, to show through. This is what gives our teeth a yellowish tint. Teeth whitening helps restore teeth to a shiny white color through the use of bleach.
Teeth whitening methods
Bleaching usually, involves making custom trays to fit your mouth, and then providing strong bleaching gel for wearing on a daily bases for a few hours a day or thru out the night.
Its best to consult your dentist to understand which whitening option is best for you.