People have been concerned, for many decades now, about having spotless white teeth and a gleaming white smile. But tooth discolouration is a persistent problem that is caused by aging and colored molecules in food and drink. Back in the Middle Ages, people used corrosive nitric acid, which bleached teeth white and kept it white for a while and then, destroyed them! However, dentists have now discovered many easy and ingenuous ways of maintaining teeth white without suffering any devastating losses.
Tooth discolouration is caused due to staining of the tooth enamel by highly-coloured compounds called tannins and polyphenols, which are found in foods like tea, coffee and berries. These stains can initially be brushed away with toothpaste, but over time, they penetrate the enamel, and a toothbrush cannot get at the deep stains. More recently however, dentists have been developing peroxide-containing gels which can tackle the stains that penetrate the tooth enamel. The peroxide forms free radicals that can destroy the part of the molecule that gives the stain its color. Tooth veneer, a non-stain covering, made of porcelain, which the dentist bonds to the tooth enamel, is another alternative to keep teeth white and shining.