Question: how long does it take for baking soda and hydrogen peroxide to whiten teeth?
Answer: Pinterest Tip: To whiten teeth, use a mouth guard with 2 parts baking soda to 1 part hydrogen peroxide, 10 minutes daily for 2 weeks. Dr. Malmstrom: It's not a good idea to use a mouth guard for whitening that's not specifically fitted for your mouth by a dentist because the hydrogen peroxide could irritate your gums.