How Does Teeth Whitening Work?

The benefits of whitening our teeth are obvious – better looking smiles, of course! But brighter teeth can also make us look more youthful, have more self-confidence, and show off our stunning post-treatment smiles more often. But how does teeth whitening actually work? And will it harm your teeth’s health? Let’s explore what it takes to brighten your smile!


Both in-office and DIY teeth whitening options use peroxide-based bleaching agents. DIY systems contain from 3-20% peroxide, whereas in-office systems like you would get from your dentist or orthodontist contain from 15-43% peroxide. The stronger the solution plus the longer you keep it on your teeth,  the whiter your teeth become.


Whitening teeth is very common and generally safe, as long as you use the product as directed or the whitening is performed by a dental professional. However, there can be risks and symptoms to watch out for.

  • Keeping bleaching gel on your teeth and gums for too long can dehydrate teeth and increase tooth sensitivity.
  • When used incorrectly, home kits can lead to burned or temporarily bleached gums.
  • The most common symptom of teeth whitening is short term tooth sensitivity, especially if you have sensitivity to begin with.

In order to avoid these kinds of issues, it’s important to remember:

  • The higher the percentage of peroxide in the whitening solution, the shorter it should be applied.
  • Healthier gums and teeth are safer to brighten, so get checked out by your dentist first. They will look for cavities and check the health of your gums and correct any issues before whitening.
  • Decide if you’re doing an at-home treatment or working with your dentist or orthodontist for an in-office treatment. Just like with clear aligners, it’s important to research which option works best for you.


All things considered, whitening is not bad for your teeth, as long as you are following all the directions. If you’re whitening from your home, be sure not to overuse the product, or keep the product on your teeth for longer than instructed. If you’re curious about the next steps to a brighter smile, be sure to ask our office about teeth brightening recommendations!