Teeth Whitening is getting cheaper and more accessible, but the more popular it gets, the more money there is to be made—resulting in lots of harmful whitening methods, products and scams that fool or hurt consumers. Remember, this is a $15B industry and the marketing often doesn’t emphasize the safety information as well.
If you’re considering whitening your teeth, this guide is for you. Make sure you know what you’re doing before jumping in—you get one set of teeth in life and it’s all too easy to damage them permanently.
By the end of this post, you’ll know:
- 1. What’s safe and what’s not when it comes to whitening
- 2. How to spot a whitening scam
- 3. How to get the best whitening results
- 4. The safest way to whiten your teeth
Why Teeth Yellow
There are two types of whitening because there are two main ways that teeth yellow.
For everyone, teeth yellowing is a normal part of aging. Our hair turns gray, and our teeth turn yellow. It’s the inner part, dentin—not enamel—that yellows. As teeth repair themselves, the new dentin is darker, and the enamel is getting thinner due to wear, and things like grinding your teeth or acids from foods you eat can thin enamel earlier, making teeth yellower sooner. The color of dentin reflects through enamel like a prism, making the tooth look yellow.
Besides aging, teeth yellow or gray due to:
- 1. Taking tetracycline before age 10
- 2. Falling on or hitting a tooth
- 3. Too much fluoride, also called fluorosis
- 4. A rare dental disorder called Amelogenesis Imperfecta (AI) which makes the teeth yellow or brown
- 5. Genetics, which determine the color of your teeth to begin with
- 6. Silver fillings
The outer part of the tooth, enamel, can also get stained when you drink tea, coffee, wine, or smoke tobacco. This is called staining, and it does not affect the inner color of the teeth.
How Whitening Works
Intrinsic
“Intrinsic” refers to whitening the inner part of the tooth, which soaks up hydrogen peroxide gel (also called whitening gel or bleach) and becomes lighter.
When the inner part of the tooth is whitened, the color that’s reflected through the outer enamel of your teeth is lighter, making them look whiter and brighter—reflecting out through the enamel like a prism.
Contrary to what you might have thought, bleach lightens the inner tissue of the tooth, not the hard, outer enamel.
Extrinsic
Removing staining on enamel (the outer part of the tooth) is called extrinsic whitening. The stains left behind by smoking, wine, tea, and coffee are usually easily removed with a polish by your hygienist at a teeth cleaning, or with polishing whitening toothpaste, which we’ll discuss in a bit.
Which Kind Is Right for Me?
It depends on whether your teeth are intrinsically yellow or if you’re just dealing with staining.
If you have extrinsic discoloration (i.e. staining from things like coffee and tea) it can be removed by cleaning the teeth with a professional teeth cleaning. Bleach will not work well on extrinsic discoloration.
If you have intrinsic yellowing, no amount of stain-removing toothpaste can lighten the intrinsic color of the tooth; you’ll need to whiten your teeth using a bleaching gel that is held up against the teeth.