Teeth whitening is performed to remove the stain and discoloration. One of the most commonly used cosmetic dental procedures; it greatly enhances the appearance of your teeth. Not a one-time procedure, it needs to be repeated from time to time if you want to maintain the bright colour.
The outer layer of the tooth called enamel gets thinner in some cases, exposing the lower dentin under it. Thinner enamel allows more of the color of the dentin to show through. A thin coating on the enamel picks up stains and tooth enamel also contains pores that can hold stains.
The most common reasons for teeth to get yellow or stained are smoking, drinking dark coloured liquids such as caffeine or red wine and not maintaining good oral hygiene. Ageing also makes teeth less bright as the enamel gets thinner and darker.