Dentures can be whitened, though the process and materials differs from whitening natural teeth.
There are a few ways to go about whitening your teeth, and which method you choose will likely depend on the severity of the staining.
Sometimes, simply soaking your teeth in a mild bleach solution (soduim hypochlorite - Clorox etc.) overnight can help remove surface stains. It is VERY IMPORTANT that you do not ingest any bleach.
Swallowing bleach (sodium hypochlorite) could kill you!
Long term use of bleach can discolor the pink gum part of your dentures; therefore, you do not want to do it too often.
Normally bleach (sodium hypochlorite) is not a recommended as a way to whiten teeth.
There are safer cleaning products specifically designed for dentures available at many pharmacies.
If your dentures are heavily stained, you may need to have them professionally cleaned by your dentist. Dentists have special equipment and techniques that can help make your dentures look new.
Talk to your dentist about what option is best for you.