“Can you whiten dentures with hydrogen peroxide?”

it could be cleaned but not whitened

Only if they have food stains on them, and then only maybe. But be aware you may also whiten the gum area too. I recommend Dr.B denture products, which can be ordered on the internet, for all routine cleaning. I also highly advise an annual checkup, where the dentist should check your gums and mouth, check the overall fit of your denture to see if there is need for an adjustment, and then they should professionally clean your denture for you. FYI... I am no longer associated with the Dental Cosmetic Center-Bay Area, nor recommended that location for dental work. Stay tuned for updates on my new contact information.

No