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Professional Teeth Whitening: Things To Know

Updated: Feb 6

Professional teeth whitening is a dental procedure that can be done in-office or with customized take home trays by your dentist. The process for how it is done will be different but the mechanism in how they bleach your teeth will be similar.

Table of contents:

Types of professional teeth whitening

There is a plethora of brands out there offering various types of professional whitening treatments. Despite the variety we can basically classify them into three distinct categories.

  • In-office without a LED light

  • In-office with a LED light

  • Take home trays that are customized

The process for each of these methods will differ so you can expect to have a different experience if you choose one over the other. The major difference among them is in how they deliver the whitening gel to your teeth and how they are accelerated to work faster.


The first type of professional whitening option is the in-office without the LED light. It is nearly identical to the one with the LED light exception for the fact that it doesn't use a light. In lieu of using the light, the whitening gets accelerated by mixing a catalyst into it.

KoR in office whitening
KoR in office whitening


  • Opalescence Boost

  • KoR Whitening in-office

The delivery method of the whitening gel involves directly applying it to the dentition. There is no need for strips or trays. The gel is literally being placed on the teeth and left as is for however long the manufacturer says it should. Different brands may require different treatment time.

Key points for this method:

  • Utilizes a high concentration of hydrogen peroxide.

  • Typically about three sessions of 15-20 minutes back-to-back.

  • Entire procedure takes a little more than an hour to complete.

  • Utilizes a gum barrier to protect the gums from turning white.

  • Cheek retractors and cotton rolls to isolate the soft tissue.

  • Has a saliva ejector to suction out excess spit.

The best part of using this way is that you don't have to lift a single finger. Your dentist will do everything for you and all you have to do is just lay back and let the teeth get whiter. We'll describe exactly what goes on step by step so you know what to expect.

What to expect

  1. Take some pain medication (ibuprofen) to decrease the discomfort.

  2. Isolate the cheeks and soft tissue with retractors and cotton rolls.

  3. Apply gum barrier to protect the gums from whitening gel.

  4. Place desensitizer on the teeth.

  5. Apply whitening gel to teeth.

  6. Place saliva suction in the mouth and wait stated duration of time.

  7. Suction off the bleaching gel after time is up.

  8. Apply second round of whitening gel.

  9. Let the teeth whiten for stated duration of time.

  10. Suction off the gel.

  11. Repeat steps 8-10 for one more round.

  12. Remove all of the isolation and gum barrier.

  13. Place desensitizer on teeth.

Once you're done your teeth may feel sensitive immediately or shortly afterwards. You may take pain killers every 8 hours to help alleviate some of the symptoms. You should also avoid staining foods for the next few days.

In-office with LED light

This method is nearly identical to the one without the light except for the fact that this does use a LED light. The purpose of the LED light is to accelerate the whitening speed and make the gel work faster. Although despite having a light, this technique will concurrently use a catalyst that is also mixed in with the gel to make it work faster. It sort of gives you a double whammy effect.

Example: ZOOM whitening


The delivery method of the whitening gel for this technique also involves directly applying it straight onto your teeth. The gel is usually viscous enough that it stays on the teeth without much trouble. Last but not least, for the entirety of the treatment you will have the blue LED light beaming onto your dentition to make it work quicker.

Key points for this method:

  • Uses a high concentration of hydrogen peroxide (26%-40%)

  • LED light is used during the entirety of each session.

  • Usually about three back-to-back sessions of 15-20 minutes.

  • Takes about an hour to complete the procedure.

  • Utilizes a gum barrier to protect the gums from getting bleached.

  • Cheek retractors and cotton rolls to isolate the soft tissue.

  • Has a saliva ejector to suction out excess spit.

The perks of having it done this way is that you don't need to do anything. Just sit back, relax, and let your dentist do all of the work for you. The whitening light definitely offers a unique experience since it beams blue light into your mouth. It almost feels like being at the tanning salon except you're at the dentist!

With that being said, we do want you to be aware that the use of a whitening light is controversial. Some studies say that it helps while others say that it doesn't. Our opinion is that it certainly doesn't hurt if you're trying to do everything that you can for whiter teeth. At the end of the day you will leave with a brighter smile.

What to expect

  1. Take pain medication like ibuprofen to decrease the discomfort intra-op.

  2. Isolate the mouth with retractors and cotton rolls.

  3. Apply a gum barrier to protect the gums.

  4. Place desensitizer on all of the teeth.

  5. Apply the whitening gel to the teeth.

  6. Leave it on the teeth and wait for the stated duration of time with saliva suction in.

  7. Suction off the bleaching gel after time is up.

  8. Repeat steps 5-7 two more times.

  9. Remove all of the isolation and gum barrier.

  10. Place desensitizer on teeth.

Teeth will most likely be sensitive afterwards so you may continue to take pain medication. Also follow all of the post-operative instructions such as avoiding staining foods for the next few days. The sensitivity should resolve by the fourth day.

Customized take home trays

This professional whitening option involves the use of customized trays where you can either whiten during the daytime or overnight. The perk is that you don't have to spend over an hour sitting at the dentist and waiting for it to work. You can complete the entire treatment at the comfort of your own home.


  • KoR Night take home

  • Opalescence custom trays

Kor Whitening take home kit
Kor Whitening take home kit

Key points for this method:

  • Requires impressions of your teeth to make the custom trays.

  • Comes in various concentrations of peroxide - The daytime treatments are more concentrated while the nighttime are less so. Can be 10%-45% in peroxide.

  • You whiten at home for about 1-2 weeks straight.

  • Does not come with a LED light.

  • Most kits come with a desensitizer or is already pre-mixed into the formulation.

What to expect

  1. Get impressions (molds) of your teeth at the dentist.

  2. Come back a week later to pick up your customized trays and whitening kit.

  3. Apply desensitizer to teeth if it comes with it.

  4. Squirt a thin bead of gel along the facial/outer surfaces of the trays. The side that faces your cheeks/lips and not the tongue side!

  5. Insert trays into your mouth.

  6. Lightly squeeze the trays all around.

  7. Remove excess gel from the gum margins with a toothbrush or q-tip.

  8. Wear trays for stated duration or go to sleep if it is an overnight product.

  9. Remove trays and brush your teeth to get rid of residual gel.

  10. Don't forget to clean your trays by brushing them.

  11. Repeat steps 3-10 for however many days you're supposed to whiten for.

The take home kits can be either daytime or overnight. The former will typically come in a higher concentration but with a shorter treatment time per day. The latter will come in a lower concentration but would require you to sleep with it. Both will give you equivalent results, it just depends on if you want an overnight product or a daytime one.

Studies have shown that lower concentration peroxide can whiten teeth to the same level but just requires a longer treatment time. That is why the overnight one requires 6-8 hours of wear in the mouth.


How professional whitening works

Whitening that is done professionally all work the same way for the most part. The main whitening agent is either hydrogen peroxide or its precursor carbamide peroxide. They form free radicals that diffuse through the tooth and oxidize all types of tooth stains. That is basically how all teeth whitening works because it revolves around the use of peroxide.

The only real differences among the types of treatments lie in their concentrations and application method of the bleaching gel.

  • The in-office treatments will typically come in a higher concentration as opposed to the take home ones.

  • The in-office will also apply the gel directly to the tooth while the take home utilizes a tray to hold the gel against the teeth. That prevents the gel from being washed away by saliva or swallowed.

Then of course there is also the inclusion of the LED light. Although the light doesn't make your teeth whiter, it does however "speed up" the process. Essentially it just shortens the treatment time by activating the peroxide to form the free radicals faster. In other words, you may have to spend more time in the dental chair without the light.


Take home vs in-office

Despite both types of professional treatments whitening your teeth the same way via peroxide, there are other types of differences between them. Namely the cost, how quickly you see results, and also the amount of teeth sensitivity afterwards.

How much they cost

All types of professional whitening will cost more than OTC products but the in-office variation will be more expensive than the take home. A lot of the cost has to do with you occupying an entire dental operatory to get the in-office treatment done. The take home version, you're not taking up chair time so your dentist can afford to charge you less.

  • Take home will cost about $300-600.

  • In-office can be anywhere from $600-1000.

Insurance coverage

Regardless of whether you are whitening your teeth professionally or using an OTC product, this procedure is never covered by insurance. Well at the very least, our dentists at afterva have never seen an insurance plan have coverage for it. So far, all of the patients have had to pay out of pocket for the treatment.

A lot of it has do with the fact that it is a cosmetic procedure and isn't necessary per say. Your teeth can still function even if they are yellow. You can speak and eat without any difficulties. For those reasons alone, your insurance will say that it is not "necessary".

Overall it is similar to how your car insurance will only pay to have it repaired if its been in an accident. It will not cover your whimsical new paint job because you want a new color. The same can be said about whitening your teeth, the insurance won't pay for a new color!

When do you see results

Of course the in-office whitening will produce results much faster than the take home variations. After all, it only requires a single treatment session of about an hour as opposed to 1-2 weeks of at home whitening with the customized trays.

You will be walking out of the dental office with whiter teeth if you decide to get it done professionally in-office. On the other hand, you'll have to wait until the entire 2 week treatment to be over before you see the finished results of the take home.

However just to remind you, both methods should produce roughly equivalent results. Its just that the one done at the dentist will be faster.


The in-office bleaching will definitely make your teeth much more sensitive than the take home trays. The reason is because you have to do three back-to-back sessions with very concentrated peroxide. That is a LOT of bleaching with a very potent gel.

The take home tends to have less sensitivity because the concentration will be less. The treatment is also spread out over about two weeks so your mouth is not being pummeled by the acidic peroxide.

From our personal experience, we rarely have our patients call us about sensitivity from the take home treatments. However we've had patients who couldn't sleep from getting the in-office whitening. That's just to give you a perspective on the difference in tooth sensitivity from the treatments.


Side effects from whitening

According to the American Dental Association, the two most common adverse effects from whitening are sensitivity and gum irritation (white gums). They say that OTC products such as whitening strips will typically start displaying sensitivity symptoms 2-3 days after starting treatment. However all symptoms should resolve on their own about 4 days after stopping.

The good news is that the majority of the symptoms are mild and transient in nature. Which means it shouldn't be a huge inconvenience to the quality of your life. That applies to most of the whitening products but the in-office can sometimes elicit more severe sensitivity.

However all of this only applies if directions are follow properly. There are whitening junkies out there who decide to whiten their teeth more than they're supposed to and that can have severe consequences.

Excessive whitening

Individuals who believe that their teeth can never be white enough, will undergo an excessive amount of whitening treatments. This will result in spontaneously bleeding gums and severe pain.

This is not a dental problem but more of a body dysmorphic disorder. The condition is called bleachorexia and it needs to be treated by a physician. The dentist can counsel the patient to stop the whitening but ultimately it will need to be treated psychologically.


How long the results last

Teeth whitening can last anywhere from 6 months to 5 years but it varies greatly from person to person. Yes, studies have shown that teeth can retain some of the whiteness even after 5 years. It may not be as white as it was on day one but it is reassuring to know that your money can go far for this treatment.

Nonetheless the longevity is highly individualized because a large portion of it has to do with lifestyle choices. If you drink a lot of coffee, tea, and red whine which are notorious for staining teeth, it will make it not last as long. If you can stay away from staining foods, you can certainly expect the whitening to last longer.

Overall most people can at least expect their treatment to last 6-18 months at the very least. Studies from as early as 1996 have demonstrated that about 45% of the cases showed some sort of relapse after 6 months. Then after 18 months about 26% of cases regressed completely.

How professional whitening compares to OTC

Having your teeth whitened professionally will always be more effective than DIY OTC methods. They will always come in a higher concentration of peroxide which is restricted to being available at the dentist only.

They will also have a superior technique for delivering the bleaching gel to your teeth such as with customized trays. If you do the in-office they can even place it directly on your teeth and prevent saliva from washing it away by suctioning it off.

Nevertheless, we'll go through all of the OTC whitening methods and explain why they're not as effective as getting it done with your dentist.

vs toothpaste

Most whitening toothpastes don't have peroxide in them so they don't actually bleach your teeth. They can only remove extrinsic stains by mechanical abrasion where it scrubs the stains off.

davids whitening toothpaste
davids whitening toothpaste

However there are a select few toothpastes which do contain hydrogen peroxide and these can oxidize intrinsic stains. Although they're still not as effective because they contain a lower concentration of peroxide and you're not brushing for that long.

Whitening in-office requires about an hour treatment but you only brush your teeth for two minutes. That hardly makes a dent in the tough to remove stains.

vs mouthwash

Whitening mouthwashes do contain peroxide which is good but once again, the rinsing duration is simply not long enough to be effective. You only swish and rinse with it for about 60 seconds total which is too short to make a difference.

optic white whitening mouthwash
optic white whitening mouthwash

vs strips

The whitening strips are a step up from the mouthwash and toothpaste because it comes with a flexible strip. The strip acts as a saliva barrier to protect the peroxide from being washed away. That allows it to work on your teeth more effectively.

crest 3d whitening strips

The downside is that the strips don't contour to the nooks and crannies of your teeth. That means the bleaching may not come out very even. It'll also sometimes bleach your gums and turn them white since it can cover them since they're not contoured.

With customized trays and the in-office solutions, you will get more even whitening and you also won't burn your gums.

vs pens

Some of the whitening pens can be used for overnight treatments but it depends on what the label says. Some of them are only for daytime use so you must read carefully.

A wonderful advantage for the pens is that they can whiten a single tooth and where that comes in handy is to bleach a dead tooth that has turned grey. Although you could do the same with the professional products but it seems like a waste of money to use it for just a single dead tooth. The pens are inexpensive so this is a great option for discolored non-vital teeth.

vs ready made trays

The ready made trays are similar to the strips in that they hold the gel against your teeth. Some of them have adhesive so they will stick to your teeth like the Opalesence Go. Although a lot of them do not have adhesive but are merely attached to a LED light. You either put the gel into the trays or put it on your teeth.

These are of course less effective than the custom trays since they're not customized to the shape of your teeth. The whitening won't be as uniform. Then there is also the fact that the peroxide concentration will be lower than professional products.

vs all natural whitening

There are all natural whitening products that do not use peroxide. For example you can find some that are based on coconut oil such as the Lumineux whitening strips.

Just for the record, the American Dental Association does not endorse any of the all whitening products. They say that there are insufficient evidence on safety and efficacy for them. They caution that a lot of the all natural products use acids from fruits which may be harmful.

vs peroxide-free

There are a couple of peroxide free whitening products out there that allege it does not use it.

However when we did research into it, we found that they were in fact related to peroxide. They may not have the word in their name but they were still derived from it or it was used to make it. We believe that disqualifies these products as being non-peroxide based... but the decision is yours to make. The good news is that they should work and bleach your teeth in the same way that hydrogen peroxide does.

Is professional whitening right for me?

There are very few reasons to deny someone from trying professional teeth whitening. The only one we can really think of is if you naturally have very sensitive teeth. Aside from that it is safe to get your teeth whitened by your dentist.

In fact it is probably safer than you doing it yourself since you are not as familiar with the products and may do it wrong! Last but not least the best reason to try it is if you've been using the DIY methods and none of them have been working.


Despite the professional whitening methods having stronger whitening gel, it is actually safer than you doing it on your own. Your dentist will do everything for you for the in-office treatment so you can't possibly do it wrong. The chances for error are reduced to nil.

On the other hand if you were doing it yourself without any supervision, you may be tempted to whiten for longer than instructed. Or you may even be using the products wrong. All of those actions will decrease its safety and efficacy.

OTC products not working

The absolute best reason to have your teeth whitened professionally is if none of the OTC products are working for you. You've tried the toothpaste, mouthwash, pen, strips, and ready to wear trays but none have given you satisfactory results. That is a sign that you should consult with your dentist.

Do not have chronic teeth sensitivity

Of course the high concentration from the professional products are significantly higher than the OTC ones so it may exacerbate the sensitivity. If you already have very sensitive teeth you may not want to start off with professional treatment. In these cases, we recommend to our patients to start off slow.

You want to use the less concentrated peroxide products and see how your teeth respond. If you can handle the sensitivity then move up one level to a slightly more concentrated one. Then if you manage to tolerate all of the OTC products, you can give the professional one a try.

Whitening products ranked by increasing sensitivity:

  1. Toothpaste / mouthwash

  2. Strips

  3. Pens

  4. Ready to made trays with or without LED lights

  5. Custom trays

  6. In-office with or without light


For professional teeth whitening, you can either do it at the dentist or at home with customized trays. Both are equally as effective for bleaching your teeth and they'll definitely give you better results than any OTC product.

The mechanism in how they whiten your teeth is very similar because they all use peroxide to do it. The only difference is in their concentration and the delivery method of the gel to your teeth.

If you've been trying the DIY methods and none of them have been working, perhaps you should try to have it done professionally with one of our dentists in Long Island City. Although you should be aware that the professional versions do cost more but you'll be more pleased with the results.



David Chen 200 x 200.jpg

About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

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Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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