Before you do anything to your teeth, it is important to know what is safe. Teeth whitening products that are sold over-the-counter are considered cosmetic products by Health Canada and The Food and Drug Administration. That means that they are not regulated in the same way as drugs.

The vast majority of at-home whitening products are safe if used as directed. The key here is the ‘used as directed’ part because the long-term effects of overusing these products is unknown.

Let’s look at the side effects of teeth whitening to see what you may experience.


Tooth Sensitivity

The most common side effect is sensitivity to temperature. It is usually the most noticeable with very cold things but hot can get you too.

The process of whitening opens the pores in your teeth which allows them to FEEL temperature changes much more easily. These pores will eventually close back up again so most people find this sensitivity lasts for 1-2 weeks.

What Can You Do To Combat This?

There are some measures you can take to reduce the sensitivity your teeth will feel after you whiten them. Photo by Sonnie Hiles on Unsplash

Toothpaste for sensitive teeth: Before, during and after using teeth whitening products, you can use a toothpaste specifically designed for sensitive teeth. These toothpastes will help to re-seal those pores so that you can not feel temperature as easily.

Drink through a straw: Keep those hot and cold liquids from hitting you teeth by drinking through a straw. This is also a good way to keep liquids that could stain your teeth (and make them less white) from touching all that newly bleached enamel.

Brush your teeth with warm water: Use an extra soft bristled toothbrush and brush with warm water. The closer that water is to the temperature inside your mouth, the less your teeth will feel it.

Irritated Gums

Anything you put inside your mouth to whiten your teeth is going to touch your gums. These whitening agents are designed to whiten your enamel and can be irritating to all of that soft tissue around your teeth.

Your gums can look white or red after whitening. What you are seeing is essentially a chemical burn – similar to a sunburn. The blood supply to your gums is very good and they will usually heal up very well in less than one week.

Can I Prevent This?

There are some things you can try in order to reduce damage to your gums.

Wipe away all excess whitening agent that gets on your gums: Use your finger, tissue or cloth to remove any and all whitener that makes its way onto your gums. Peroxide has to sit for a while to burn you, so the less time the better.

Place a barrier on your gums before whitening: You can use sensitive toothpaste or Vaseline to cover your gums before applying the whitening product to keep it off of those tissues. This is especially helpful if it will be hard to reach your gums while everything is in place.

Rinse with warm saltwater 3 times a day: If those tissues end up a little irritated, warm saltwater will help. Get one glass of very warm water, add a teaspoon of salt and swish, spit, repeat until the cup is empty.

No Colour Change

There is always the possibility that your teeth will not be the colour you want or expect after you use a whitening product.

There are a number of reasons that this may be the case…

  • Some teeth are discoloured due to medications or abnormalities in how the tooth formed. These teeth can be very resistant to bleaching and can require other procedures by a dentist. If you think this may be the reason your teeth are not getting whiter, talk to your dentist.
  • Fillings on teeth that are white in colour, will not change colour with the use of whitening products. Whitening products can only change the colour of enamel (natural tooth structure). If your old fillings do not match your newly whitened teeth, you will need your dentist to replace them in order for them to match.
  • Porcelain crowns or veneers on any of your teeth will not whiten for the same reason that fillings will not. I would caution you to talk to your dentist about whitening before you do it in cases where front teeth have porcelain as it can be very expensive to replace these.

I hope that you found this information useful. Please comment below about your experiences with teeth whitening products.

Wishing you the whitest smile,

Dr. Jen

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