does teeth whitening cause cavities?

I’ve been doing teeth whitening off and on for most of my adult life. I take a lot of pride in my appearance and having a bright smile is important to me. Nobody ever said that it could damage my smile. To be fair, I don’t get a lot of cavities, but my teeth are more sensitive these days and I hear that’s a warning sign. Since I started reading up on it, I’ve stopped using whitening toothpastes and do not plan to use the system I got from my dentist anymore, but I’m worried I’ve caused irreversible damage. If it has caused damage, is there anything I can do to reduce the risk?



Dear Thad,

custom-fitted teeth whitening trays

It sounds like you got a mix of inaccurate information and half-truths. Let’s break down what healthy teeth are like, how cavities form, and how teeth whitening products work.

Your Enamel is Strong and Packed with Minerals

Your enamel is the hardest substance in your body and it protects the under layers of your teeth. However, the enamel shouldn’t be thought of as unchangeable or impermeable. For example, people who brush really hard or grind their teeth can wear it down over time. Plus, acid can cause the minerals to seep out of your teeth which leaves them susceptible to decay. And, believe it or not, your teeth are actually porous as well. Your tubuals, which provide a pathway from the outside of your tooth to the inside, are typically closed shut though.

Under Optimal Circumstances, Your Teeth Will Remineralize

Bacteria and the things you put in your mouth, including food and dental products, can change your oral pH, and once you have an acidic mouth, teeth demineralize. The opposite is true as well. If you can restore pH and have healthy minerals in your saliva, your teeth will pick them up. This in mind, if you constantly create an acidic environment and never give your teeth a chance to remineralize, you will have weak spots in the enamel and decay can set in. This is why fluoride is such a huge thing. It can strengthen teeth even if they aren’t given the ideal remineralization environment.

Teeth Whitening Products are NOT Inherently Dangerous

Products designed to whiten your smile are not the enemy, but they do come with some side-effects, depending on what you’re using.

Acidic Products: Generally speaking, teeth whitening products are acidic, but not all are. That’s a worry if you constantly use one that is lower than a 7.0 pH and never get your mouth back to the neutral state or aren’t using fluoride to help remineralize. Chances are, however, you’re using a fluoride toothpaste. Unless you’ve actively looked for one that isn’t, it’s standard practice to include it. You may also struggle with this more if you aren’t a great brusher or delight in acidic or sugary foods, such as coffee, sports drinks, citrus fruits, and sodas. (The bacteria which causes decay noshes on carbohydrates and releases acids as a byproduct, which is why sugars contribute too.)

Abrasive Products: Many toothpastes lift surface stains with their abrasiveness. If you’re using a whitening toothpaste, there is some chance it’s abrasive and wearing down the enamel. As the enamel thins, you’ll have more sensitivity and may be more susceptible to decay. It also tends to sabotage your efforts. Many of them work by their abrasiveness removing the surface stains. Unfortunately, that also means they’re scratching your enamel which makes it easier to pick up more stains.

Professional Products: Professional-grade teeth whitening systems don’t just scrub off surface stains. They open the tubuals and oxidize from within, eliminating stains below the surface. The change is not permanent; the tubuals typically close up within a day or two. That’s why you’re told to avoid highly-staining foods and beverages altogether after treatment for a few days. Once they close back up, it’s business as usual. However, during those couple of days, you may experience some sensitivity. It doesn’t mean you’re more susceptible to decay though.

Fluoride Will Help

You don’t have to give up teeth whitening. However, you should take the sensitivity as a warning sign. Mention it to your dentist, so he can see if you’re already dealing with a cavity or have enamel erosion. If there’s no decay, fluoride, either provided in-office or via an over-the-counter gel or mouthwash, should help with any demineralization and sensitivity as well.

This blog is sponsored by New Orleans Dentist Dr. Duane Delaune.