The beginner's guide to teeth whitening

Most people desire a bright, white smile they can show off with confidence. But many factors can conspire together to discolor teeth — some you can control and others you can't. Fortunately, there’s a potential solution for pesky stains: teeth whitening.

If you’re new to tooth whitening and have questions or feel apprehensive about it, this guide has the information you need.

What causes stained teeth?

Teeth can become discolored for a variety of reasons. Some of the most common factors¹ include:

• Tobacco use: The tar and nicotine in cigarettes, cigars, and chewing tobacco can stain teeth.
• Pigmented foods and drinks: Foods and drinks such as coffee, wine, soda, tea, tomatoes, and berries contain colored pigments that can accumulate and eventually stain teeth.
• Poor dental hygiene: By not taking proper care of your teeth, stains accumulate on your teeth and bacteria-laden plaque can linger in your mouth. Eventually, bacteria can wear down enamel and exposes the dentin — which is brown — underneath.²

Other causes of staining that are less controllable are aging, genetics, and medications. These typically lead to intrinsic stains, meaning they occur inside the tooth.³ Intrinsic stains occur when tooth enamel thins out or gets worn down, exposing the dentin underneath. Dentin is usually yellow or gray⁴ in color. Because these stains occur inside the tooth, they’re more difficult to remove than surface stains.

What is teeth whitening?

Whitening is the process of restoring the natural color of your teeth and removing stains that have set in over time. Treatments are available to address both intrinsic and extrinsic (i.e., surface) stains.

Whitening products are available either from your dentist or over the counter, and there are many options, including special toothpastes, chewing gum, strips, gels, rinses, trays, and bleaching. The American Dental Association recommends consulting with your dentist to determine the right teeth whitening option for you.⁵

How does teeth whitening work?

Whitening products often use hydrogen peroxide or carbamide peroxide to bleach the teeth and remove discoloration. These ingredients cause a safe chemical reaction that can change the color of teeth by breaking up staining molecules called chromogens.⁶ Bleaching products can treat both extrinsic and intrinsic stains. They're available from your dentist or over the counter.

Whitening toothpaste is also effective for extrinsic stains. It usually does not contain hydrogen peroxide or carbamide peroxide. Instead, it scrubs away stains on the surfaces of teeth.⁷

In-office whitening is usually done in about an hour. It will typically have more noticeable effects because a dentist will use a higher concentration of bleaching agents than is found in take-home or over-the-counter solutions. For this reason, you'll also start noticing results sooner. Take-home or over-the-counter treatments may take several days or weeks to complete.⁸

Note that teeth whitening doesn’t work on dental restorations such as crowns, veneers, and fillings.⁸

Does whitening damage your teeth?

Teeth whitening is generally safe and effective as long as you use products approved by dentists. It should not damage your teeth as long as the treatment is used as instructed. It can cause mild side effects, depending on the treatment. The most common side effects are tooth sensitivity and gum irritation. However, both symptoms are temporary and should subside shortly after the whitening treatment is complete.⁵

How long does teeth whitening last?

Teeth whitening isn’t permanent, and stains can return without proper care.⁷ For longer-lasting results, limit pigmented foods and drinks in your diet, brush and floss your teeth every day, get professional cleanings every six months, and avoid smoking.⁷

If you eat food or drink a beverage that can cause staining, brush your teeth or have a glass of water to rinse out your mouth and help wash away the acids.² Wait at least one hour to brush if you eat or drink something acidic, such as tomatoes, soda, or coffee. This gives saliva a chance to wash away acids and restore enamel.⁹ Drinking through a straw can also help prevent liquids from staining your front teeth.⁷

References

¹ https://www.mouthhealthy.org/all-topics-a-z/teeth-whitening 

² https://www.medicalnewstoday.com/articles/321480#treatment

³ https://www.webmd.com/oral-health/guide/tooth-discoloration

⁴ https://www.verywellhealth.com/dentin-definition-of-dentin-1059420

⁵ https://www.ada.org/en/member-center/oral-health-topics/whitening

⁶ https://www.youtube.com/watch?v=5VVtzd0guas

⁷ https://www.webmd.com/oral-health/teeth-whitening

⁸ https://www.webmd.com/oral-health/teeth-whitening-and-bleaching

⁹ https://www.cuimc.columbia.edu/news/brushing-immediately-after-meals-you-may-want-wait