Having a bright white and healthy smile is the best thing one can possess and offer to others. A pretty smile spreads positive energy and is one of the most important beauty traits.

Pearly teeth improve the self-esteem and are a sign of overall health.

On the other hand, damaged or yellow teeth look extremely unattractive and are caused by genetics, ageing, poor hygiene, tobacco, foods, medicines, drinks, diseases, dental materials, environment, or trauma.

Source: https://healthvipes..com/2017/10/how-to-whiten-your-teeth-at-home-after.html

You didnt even mention any method