Over-the-counter teeth-whitening strips may actually be doing more harm than good.
Researchers conducted three studies and found the active ingredient, hydrogen peroxide, can damage the protein-rich tissue located beneath the enamel.
That tissue, called dentin, makes up most of the tooth.
But the researchers also say their studies did not address whether the possible tooth damage is permanent.
Experts say if you want to brighten your pearly whites you should go to your dentist where it might be safer.