How to Whiten Teeth, According to Dentists

Your teeth can begin to lose their luster for a handful of reasons, but there are a few ways to get them to a whiter, brighter state. Sure, brushing them two times a day can help in removing surface stains and lessen the yellow appearance a tad, but there is another method that works the best: teeth whitening.

There are a variety of ways you can whiten your teeth at home and even on a budget, such as brushing with baking soda or hydrogen peroxide, or using an at-home whitening strip, gel, or an LED mouthpiece with whitening serum. These days, the journey to a sparkling smile can come with an endless amount of options to choose from; it all depends on how often you want to whiten them or if you want a dentist to take over.

Since there are multiple ways to achieve whiter teeth, we spoke with dentists to learn how to whiten your teeth at home most effectively and what the process looks like in the dentist office, should you choose the professional route.

Experts Featured in This Article

Joyce Kahng, DDS, is a cosmetic and restorative dentist and owner of O+M Dental Studio in California.

Danny Snyder, DMD, is a practicing family and cosmetic dentist based in Washington.

How to Whiten Teeth Professionally

The professional teeth whitening systems that are used in dentist offices provide effective results in the shortest amount of time possible. “The active ingredient between home whitening and office whitening is usually a form of hydrogen peroxide,” Joyce Kahng, DDS, a cosmetic and restorative dentist, says. “While the ingredient is the same, professional systems differ because of two main reasons.”

Professional grade services utilize hydrogen peroxide at 25-40 percent, whereas at-home versions use 6-10 percent, she says. The second difference is that all of the soft tissue — aka your gums, cheeks, and lips — is blocked off and protected with a protective device so only your teeth are exposed, “which not only allows dentists to safely use such high concentrations of hydrogen peroxide but also provides the optimal environment for the whitening product to work, free of saliva and contaminants,” says Dr. Kahng.

During the in-office treatment, a fresh whitening solution is mixed and applied three to four times throughout the session. Danny Snyder, DMD, a practicing family and cosmetic dentist, says most treatments also include an LED light that activates the whitening gel and speeds up the process. In order to prevent the concentrated whitening gel from burning the patient’s gums, a barrier gel is carefully applied to the gums and hardened with a UV curing light.

“Depending on how white you want your teeth to be, you can do one to four 15 minute sessions where fresh whitening gel is applied to the teeth,” Dr. Snyder says. Dr. Kahng adds: “Afterward, the barriers are removed and the patient is instructed to avoid anything that stains teeth for 48-72 hours.”

While pain tolerance varies from person to person, Dr. Snyder notes that “most patients report intense sensitivity for a few days after, even though a desensitizing agent is applied to the teeth at the end of the appointment.”

How to Whiten Teeth At Home

There are a few ways you can whiten your teeth at home. Both experts we spoke with recommend using a hydrogen peroxide-based strip or tray from your dentist. A custom whitening tray is ideal for two reasons. “One, the custom fit means that an even layer of whitening gel gets applied to every tooth, and two, the gel your dentist gives you to fill the trays has a higher concentration of hydrogen peroxide or carbamide peroxide, which means you achieve better results in a shorter period of time,” Dr. Snyder says.

Dr. Kahng agrees that custom whitening trays from your dentist are the most ideal, but for those who don’t have access to that, “the next best bet is to use an over-the-counter whitening tray such as the ones from Opal.” (She is referring to the Opal Prefilled Whitening Trays ($58), which contain 11 percent hydrogen peroxide.)

Whitening strips like the Crest 3D Whitestrips ($46) are also a good go-to when you want to take your teeth whitening journey at your own pace. “Consider using them daily for a week if you would like to see faster results, but for those who are sensitive, skip a day or two in between,” Dr. Kahng says.

How to Whiten Teeth If You Have Sensitive Teeth

If you have sensitive teeth, before whitening them, Dr. Kahng recommends using a sensitivity toothpaste with potassium nitrate starting at least two weeks prior to your whitening treatment. A good option would be the Sensodyne Sensitivity Protection Toothpaste ($13).

“I also recommend using the whitening products for shorter periods of time than what is recommended and to wait more days in between each treatment,” she says. “It’s better to be consistent and wearing them to the point of intense sensitivity can derail progress.”

Dr. Snyder says whitening your teeth in the evening before bed may also help those with sensitive teeth during the whitening process. “Breathing in cold air and drinking hot or cold drinks make the sensitivity worse, so if you whiten before bed, eight hours of sensitivity recovery happens while you sleep.”

He adds that if you have sensitive teeth, you should consider buying MI Paste ($26), which counters sensitivity. “Once you’re done whitening, apply a thin layer of MI paste to the inside of your whitening trays, wipe away any excess, and wear them to bed. By morning, the worst of sensitivity will be behind you.”

How to Whiten Teeth With Braces

It’s best to avoid whitening your teeth when you have braces or teeth aligners like Invisalign. “Traditional whitening during braces is not advised because the part of the tooth under the bracket glue may not whiten the same as the rest of the tooth,” Dr. Snyder says. “Using a whitening toothpaste while in braces tends to keep the teeth from yellowing.”

If you’re eager to whiten your teeth for an upcoming event, Dr. Snyder recommends using a purple toothpaste. “I like to call these ‘tooth makeup,’ meaning that it gives the illusion of whiter teeth for up to a few hours.”

Side Effects of Teeth Whitening

For both in-office and at-home teeth whitening treatments, there are a few possible side effects to keep in mind. Our experts say you can experience tooth sensitivity, which can be alarming for some patients but is a “normal and inherent part of whitening,” Dr. Kahng says. You might also experience tissue burning, which can occur if too much gel is applied.

While side effects may be uncomfortable, both experts explain that whitening does not damage your teeth, unless you whiten them at an extreme and excessive rate, such as every day for long periods of time or multiple times in a day.

When to Avoid Teeth Whitening

Anyone with healthy enamel and no cavities is considered safe to whiten their teeth. However, there are some instances when you should avoid the treatment, including if you are pregnant or breastfeeding. Also, “People with extensive acid erosion due to bulimia, reflux, or a lemon-sucking habit should be careful not to whiten excessively,” Dr. Snyder says. This is because the above may make you more susceptible to teeth damage.