There are various factors involved in the discolouration of teeth. They may be hereditary (natural tooth discolouration or ageing), pathological (tetracycline use during the period of tooth formation) or due to lifestyle factors (drinking coffee, tea, smoking, wine and antidepressants). Bleaching lightens teeth and helps to remove stains and discoloration. It is among the most popular cosmetic dental procedure performed because it can greatly improve how your teeth look along with improving the overall look of your face. But Bleaching is not a one-time procedure. It will need to be repeated from time to time if you want to maintain the brighter color.