Professional Teeth Whitening: Everything You Need To Know


Medically Reviewed

Dr. Joseph Willardsen is a cosmetic and biomimetic dentist and the president of True Dentistry in Las Vegas.
Joseph G. Willardsen, D.D.S. Cosmetic / Biomimetic / Reconstructive Prosthetic Dentistry
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Professional teeth whitening is often an efficient, safe and effective choice for brightening your smile. But there’s plenty to consider, including cost, your lifestyle habits and whether a comprehensive in-office treatment or a custom take-home-tray is the better choice.

Professional Whitening Methods

The two main products used for teeth whitening are hydrogen peroxide and carbamide peroxide. Unlike a whitening toothpaste that uses an abrasive ingredient to mechanically remove surface-level stains, the oxygen molecules within these whitening agents weaken your tooth stains on a molecular level.

Many over-the-counter (OTC) whitening strips, kits and pens also use a form of peroxide. The difference between these and professional teeth whitening is the chemical concentration.

“In the office, we use a very high percentage of hydrogen peroxide because we have the capability to isolate the teeth,” says Joseph Michael Brofsky, head of pediatric dentistry at Cohen Children’s Medical Center of New York. “We use a special rubber dam to protect the patient’s gums because if peroxide gets onto the gums, it would burn them.”

Like at-home whitening products, there are a variety of professional teeth whitening methods. In-office professional whitening is a quicker, albeit more costly way to lighten up your pearly whites. Meanwhile, custom take-home trays fall somewhere between in-office professional whitening and an OTC whitener in terms of treatment time and cost.

In-Office Whitening

In-office professional whitening treatments are typically completed in several short appointments but will depend on your unique needs. A whitening agent is left on for 15- to 30-minute increments, and the entire appointment should take no longer than an hour and a half.

There are a few types of in-office whitening treatments:

  • A high concentration hydrogen peroxide gel, which is applied by a syringe.
  • A hydrogen peroxide combined with a high-intensity light, like LED, UV or halogen. The light is applied by a lamp or laser device that sits directly outside of your mouth.

Halogen light and laser light increased teeth lightness more than hydrogen peroxide alone, according to a 2016 study in the Journal of Conservative Dentistry. After three weeks, study participants in the halogen and laser light groups still had the white teeth color achieved during treatment while the non-light group had “shade rebound” after just two weeks—initially brightened teeth became darker.

However, some studies show no benefit from using a light tool such as a laser or lamp over a whitening gel alone.

Aside from effectiveness, is light exposure safe for your smile? A 2020 study in Materials found that tooth cells recovered well after LED light-accelerated technology, concluding that most side effects are “temporary and transient.”

What to Expect at an In-Office Teeth Whitening Appointment

In-office whitening typically involves several steps:

  • Your dentist will use a tooth shade chart to determine the current shade of your teeth. You’ll discuss how many shades lighter your smile may become after whitening.
  • Your dentist will then use a pumice tool to polish your tooth and remove any remaining plaque.
  • To ensure the whitening agent doesn’t touch any fleshy parts of your mouth like your gums, cheeks or tongue, your dentist will use tools to keep your mouth open. A barrier is placed along the gum line.
  • Your dentist then applies the whitening agent and leaves it on for up to an hour. This is also when your dentist would use light activation if that’s part of your treatment.
  • If the specific whitening agent requires additional coats, your dentist will reapply it.
  • Once the whitening process is complete, your mouth is rinsed. Your dentist may apply fluoride, which will help mitigate any potential sensitivity.
  • You and your dentist discuss if your teeth have reached the desired shade and the lifestyle habits you’ll need to practice for the next day or so to let the whitening agent sink in. These include not eating brightly colored foods and resisting coffee and red wine. Immediately after whitening, your teeth are dehydrated, making them extra susceptible to liquid and food stains.

Even if you stick to your dentist’s recommended regimen of resisting bright foods, coffee and wine, your teeth may appear a bit darker a few days after whitening. But don’t be discouraged. The dehydration caused by teeth-whitening makes them look immediately bright right after your procedure. After a week, if your teeth are not at your preferred shade, speak with your dentist about whether or not there’s potential for them to become lighter with at-home products or more in-office visits.

Take-Home Trays

While in-office whitening is fast, custom take-home trays require some diligence on the part of the patient. They may be your only treatment or a follow-up treatment to in-office whitening if your dentist believes your smile is prone to getting new stains again soon.

With a professional take-home-tray, your dentist will make an impression of your teeth for a custom-fabricated tray. Because this tray will fit perfectly to the shape of your mouth, it will typically give you more comprehensive whitening results than OTC trays. Instead of a hydrogen peroxide-based gel, you’ll most likely get a carbamide peroxide-based gel to place in the tray and use at home. Even though it doesn’t whiten as quickly as a hydrogen peroxide-based gel, you’re less likely to experience sensitivity if you accidentally get it on your gums, cheek or tongue.

The concentration of the gel your dentist gives you for your custom-fit trays ranges from 10% to 38% carbamide peroxide, according to the American Dental Association. Your duration of treatment will also vary, from wearing your tray from two to 10 hours a day, and for up to 28 days. Over-the-counter trays come with a similar percentage of carbamide. The difference in quality is in regards to fit. A custom tray will fit directly around your teeth, giving little room for the gel to slip up to your gums or miss whitening hard-to-reach crevices.

In-Office Teeth Whitening Vs. Custom Take-Home Trays

While both at-home whitening and in-office whitening are effective under the supervision of your dentist, there are a few major differences.


Custom, take-home-trays are more affordable than in-office whitening, but still more expensive than over-the-counter trays and other at-home whitening products. They typically range from $300 to $600. Meanwhile, in-office whitening costs $800 to $1,000, says Brofsky.

What about dental insurance? Since teeth whitening is a cosmetic treatment, it’s not covered by dental insurance.


Your dentist can usually complete in-office whitening treatments in one or two appointments, depending on the severity of your stains and your dentist’s thoughts on how many shades whiter your teeth can become. Each session is usually 60 to 90 minutes at most. Meanwhile, you’ll need to wear your custom, take-home-trays several hours a day for up to a month. For ideal results, your dentist may recommend a custom-fit tray for touch-ups even after in-office whitening.


No tooth whitening treatment lasts forever. But you still want to do everything you can to keep your pearly whites shining bright for months and years to come. Experts recommend continuing a rigorous oral care routine, cutting out bright colored foods, coffee, red wine and soda, and using over-the-counter touch-up products.

When it comes to which treatment will last longer, there’s no definite answer, although with custom trays, frequency is key. You can wear at-home trays regularly for up to three to five years, whereas an in-office visit may be complete in one or two sittings. That means the bright shade of your teeth while using trays may last longer, since you can order a professional whitening agent from your dentist to be used at home in your reusable dental tray for touch-ups.

How to Decide if Professional Teeth Whitening is for You

Wondering if you’re the ideal candidate for professional teeth whitening? If you want to go at least two shades lighter and don’t want to experiment with OTC treatments—or have tried them without much success—a professional treatment could be for you, says Brofsky.

Pre-Whitening Topics to Discuss With Your Dentist

Several factors affect whether your whitening results live up to the sparkling smile you envision. For starters, whitening substances can’t penetrate plaque and buildup. And putting a tooth with a cavity or exposed roots through a whitening procedure could lead to discomfort and sensitivity. A checkup and professional cleaning prior to in-office whitening is a must.

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Finally, your dentist can review any areas of your teeth that the whitening agent may not be able to penetrate, including:

  • Areas overexposed to fluoride.
  • Past dental work such as a porcelain tooth or bonded area.
  • Trauma that caused the inner layer of your tooth, or dentin, to darken.
  • Exposure to tetracycline antibiotics during tooth formation.

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On SNOW's Website


The American Academy of Cosmetic Dentistry. American Academy of Cosmetic Dentistry. 03/15/2021.

Bhutani N, Shome V, Patil P, Singh V, Jyotsna V, and Jain A. Evaluation A of bleaching efficacy of 37.5% hydrogen peroxide on human teeth using different modes of activations: An in vitro studyJournal of Conservative Dentistry. 2016;19(3):259–263.

Marto M, Laranjo M. Cytotoxic Effects of Zoom® Whitening Product in Human Fibroblasts. Materials. 2020;13(7): 1491.

Oral Health Topics. American Dental Association. Accessed 03/15/2021.

In-Office Teeth Whitening: Professional Advantages, Costs and Options. Consumer Guide to Dentistry. Accessed 03/15/2021.

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