Is Teeth Whitening Safe?

Mar 13th 2023

I frequently get questions about teeth whitening and safety. Sometimes, they're not even questions. I'm often told that "everyone knows" how teeth whitening strips enamel from your teeth and damages them for good.

It seems to me that as a dentist who no longer sees patients, I'm in an unbiased position to set the record straight: Teeth whitening done correctly is safe, and it does not work by stripping enamel from your teeth!

Many people may have gotten the wrong idea because of how older whitening formulas used to work. Remember "Pearl Drops" for smokers? It used harsh abrasives that literally scoured away the stains and took off a little enamel in the bargain! (Read my article featured below to learn why stripping enamel makes your teeth more yellow, not whiter!)

And of course, the idea that you have to scrub your teeth as if you're cleaning the grout in the bathroom tiles never seems to go away. If I got paid for every mangled toothbrush resulting from too much "elbow grease" during brushing, I'd be a very rich woman! (Even though dentists have been recommending nothing but soft bristles for years, the medium and hard ones are still on the market. Enough people stubbornly believe they have to attack their teeth to get them clean and white, that stiff bristles sell well!)

Today, we live in the age of chemicals. Abrasives are the enemy. They absolutely will strip enamel from your teeth, and they do cause permanent harm. But teeth whitening works with chemical agents, not abrasives. These whitening (or bleaching) agents actually react with the stain deep inside your teeth to neutralize it. There's no harmful stripping of enamel.

View your teeth under a microscope and the surface will look something like a honeycomb. Thousands of tiny tubes (called "enamel rods") are lined up side by side forming the enamel, and beneath them "dentin tubules" form the tooth's inner layer. Over time, the stains on the tooth's surface work their way through this system of tubes and become trapped within the honeycomb structure. The stain is now part of your tooth. We dentists call this "intrinsic stain". It can't be brushed away, no matter how hard you try.

Now, it takes a lot of time for intrinsic stain to form because the tubes in the "honeycomb" tend to be "plugged up" with organic matter. If they were wide open, your teeth would be terribly sensitive to temperature changes, especially cold. In order to work, bleaching agents need to remove the plugs so they can penetrate to the inner layer of your teeth, where they work their magic. The active ingredient loses effectiveness quickly, so no need to worry that you're trapping harmful chemicals inside. After some time (usually a couple of weeks), the plugs return.

This explains why it's common for teeth to become sensitive during and after the teeth whitening process, and why the effect subsides. Sensitivity is the number one side-effect that gives teeth whitening a bad rap, and makes people think it's doing permanent harm. The strength of the whitening agent, how it's applied, and how long/frequently the teeth are exposed are all factors in sensitivity. So is the degree of temperature sensitivity you have before you whiten. Talk to your dentist first if you're worried about sensitivity.

The bottom line is that for the vast majority of us, teeth whitening is a perfectly safe and harmless beauty treatment that almost anyone can afford. I believe everyone should at least consult with a dentist to be sure they have healthy teeth before they start* and discuss the various products and whitening technologies available (home-whitening or whitening at the dentist 's office with professional strength gels and high-tech lights that speed the process, for example). You may decided to use an over-the-counter product because it's more affordable. You may have to try more than one product, even with your dentist, before finding the one that gives you maximum results with minimum sensitivity. But if you're like most of today's beauty conscious patients, you'll come away smiling!!!