There are some situations where patients would have stains, due to medications or fluorosis, that are not effected by tooth whitening. Dental veneers would be an option to disguise the staining and even out your smile.
Another reason to have dental veneers made is if you have too big of a spacing between your teeth.
The dental veneer is a thin piece of porcelain and it fits on the facial surface of the teeth that need cosmetic correction. Veneers are used for cosmetic purposes, therefore are applied on the teeth that are visible when you smile or talk.