Can Tooth Whitening Damage Your Gums?

Dr. Kyle Hornby

Tooth whitening is in high demand these days. People want a whiter, brighter smile and tooth whitening is a fairly simple and low-cost way to achieve it. So, is tooth whitening safe or can it harm your teeth and gums? It's a common question and a really important one. Let me break down tooth whitening safety!

How does tooth whitening work?

Tooth whitening gels and toothpastes contain carbamide peroxide in varying concentrations. The stuff you get at the drugstore is weaker in concentration but still effective. The stuff you get at your Kitchener Dentist is higher in concentration, still effective, but it works much faster.

When whitening gels and toothpastes come in contact with your saliva, you get some byproducts. Molecular oxygen is one of them. Many of you will remember those carpet cleaner commercials from the 90s touting "the power of molecular oxygen!"...well, tooth whitening products work the same way. The molecular oxygen in whiteners diffuses through your enamel displacing stain particles that discolour your teeth. The result? Less-stained, brighter, whiter teeth!

Does tooth whitening damage your teeth?

No, no, no. There is no peer-reviewed research showing that tooth whitening damages teeth. It's never been shown. What whitening will do is cause a brief increase in tooth sensitivity. Cold things, sweet things, and acidic things will kind of "zing" for a while. The good news is that, once you stop whitening, your teeth will return to normal within about a week or so.

Now, there are 2 important things to remember:

  1. The increase in sensitivity does not result from and damage or structural change to your teeth.
  2. You can use Sensodyne toothpaste to mitigate or lessen this increase in sensitivity so you can stay comfortable while whitening.

Can tooth whitening damage your gums?

The ingredients in whitening gels and toothpastes are certainly safe for your teeth. But, what about your gums?

Hydrogen peroxide in whitening gels can have harmful effects in high concentrations over long periods of time. However, these effects have never been demonstrated in humans following standard tooth whitening protocols. In fact, a study of patients using excessive whitening protocols for over 6 months did not show any harmful effects even 7 years later. A useful article on whitening safety by Whitening Guru, Dr. Harold Heymann is available here. The best advice is to follow your Dentists instructions and to minimize or avoid contact between the whitening gel and your gums.


Tooth whitening is a popular and readily available technique for improving the appearance of your smile. However, it is important to ensure that it does not interfere with your overall health. Using an appropriate whitening product for a safe amount of time is key. I would recommend consulting your Kitchener Family Dentist about safe and effective whitening protocols before you start.

Best of luck with your tooth whitening experience!

By Dr. Kyle Hornby, Kitchener Dentist

If you would like to book a Meet & Greet appointment, give us a call at (519) 576-8160 or request a consult with me here.

Our Kitchener Dental Clinic is conveniently located Downtown and we are a short drive away for families in Kitchener, Waterloo, Breslau & Stratford.

This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to be a substitute for professional advice, diagnosis or treatment. Always seek the advice of your Kitchener Dentist or other qualified healthcare provider with any questions you may have regarding a dental condition or treatment.

Enjoy a fresh start.
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