Oh, the things we do for beauty. Remember the curly perms that took our hair from naturally straight to permanently kinky curly, but came with chemical fumes that nearly took us out in the process?

Go back one generation before that and you’ll find our moms ironing (yes, ironing!) their own hair to make it stick straight. On actual ironing boards. Using the same iron they used to press their clothes. Is something burning?!?

Good times.

Home teeth whitening kits are a popular and easy way to brighten your smile. You can buy a variety of teeth whitening strips at the grocery store and you can get more potent, faster-working formulations from your dentist. You place the strips over your teeth and leave them in place for a few hours.

A few days or weeks later? Voila! Brighter, whiter choppers.

Americans spend more than a billion dollars a year on these teeth whitening products. But a new study shows that while these products do whiten teeth, they may also be damaging them.

In three new studies, researchers at Stockton University in New Jersey found that hydrogen peroxide, the active ingredient in over-the-counter teeth whitening strips, can damage the protein-rich dentin tissue found beneath the tooth's protective enamel.

Tooth Structure 101

Your teeth are made up of three distinct layers: outer tooth enamel, the underlying dentin layer, and the connective tissue that binds the roots to the gum. Previous studies have focused on the outer enamel layer, which is reasonably hardy and unbothered by the peroxide in teeth whitening strips.

The dentin layer is where the problems begin. In addition to making up most of the tooth structure, the dentin layer is also high in protein and collagens. In the most recent study, the researchers demonstrated that the major protein in the dentin is converted to smaller fragments when treated with hydrogen peroxide, which weakens the overall structure of the tooth.

The Results

To strip or not to strip? Teeth whitening strip, that is. Well, the researchers point out that their experiments did not address whether collagen and other proteins in the teeth can be regenerated, so it is unknown at this stage if the tooth damage is permanent.

So, you’ll have to decide for yourself if having brighter teeth is worth the risk of potentially weakening them in the long run.