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Brushing and Whitening Strips: When To Do It

We recommend brushing 30 minutes before using teeth whitening strips and then brushing again 30 minutes after you finish whitening. However, this may be different from manufacturer instructions but we will explain our reasoning.

risewell toothpaste on toothbrush

Table of contents:

Instructions as per whitening strip manufacturers

Upon sampling a couple of common teeth whitening strip brands, we could find no directions as to what you should do in regards to brushing. There is no mention about if you should brush before using the product. There is also no mention about if you should brush after using their product.

HISMILE pap whitening strips and other products

Most of them don't say anything at all or give an incomplete answer and that includes Crest. However, Crest does have a short article in regards to what you should do with brushing and using their bleaching strips.

Directions from different brands

Instructions for Moon Dissolving Whitening strips:

  1. Place one strip on front of teeth (one for top and one for bottom).

  2. Let dissolve (takes about 15 minutes).

  3. For best results, avoid eating or drinking for 30 minutes after use and use two times a day for 14 days."

Instructions for Equate Timeless White Strips:

  1. Remove product from package.

  2. Place adhesive side on front of teeth, applying lower first.

  3. Wear for 30 minutes to enjoy a whiter smile.

Instructions for Lumineux Whitening strips:

They do specifically mention brushing afterwards but don't say anything about before using their product.

  1. Apply upper and lower strips for 30 minutes.

  2. Remove, rinse with water or brush.

  3. Recommended Routine: Use strips 7 days in a row, then 1-2 times a week thereafter to maintain your white smile!

Instructions for Crest 3D Whitestrips:

  1. Apply Crest 3DWhitestrips Professional Effects to upper and lower teeth once daily for 30 minutes total for 5 consecutive days.

Article from Crest

Crest must've had a lot of questions in regards to their product and brushing because they do have an article to address this question. They do have a concise answer on if you should brush before and after but they don't give too much of an explanation.

crest white strips - displayed with all of the packets

Crest says that you can brush right after you finish the whitestrips. However they say that you should NOT brush immediately before applying the strips to your teeth. Their explanation for the latter was that it may result in gum irritation. They recommend to "wait some time" after brushing before using the strips.

That was it from their article with no additional information... Nonetheless, we'll give you our take on what you should do with a more in-depth answer. Hopefully we'll satisfy your curiosity.


Brushing before using whitening strips

You should definitely brush your teeth and floss prior to placing the whitening strips on because it increases its efficacy. The bleaching material will certainly work more effectively if you give it a clean tooth surface to whiten.

Example: Imagine after eating a peanut butter sandwich and then trying to whiten immediately afterwards. It most likely won't work very well since there will be food residue that blocks the strips from being in contact with your enamel.

You may be wasting your strips if you try to whiten on a non-clean tooth surface. Although you may whiten the peanut butter but that isn't exactly an outcome we're looking for. It makes sense if you think about how whitening strips work.

Therefore in order to maximize the efficacy of your at home whitening and taking into account Crest's recommendation to minimize gum irritation, this is our protocol for what to do.

Protocol for brushing before using the strips:

  1. Brush your teeth for two minutes.

  2. Spit out and rinse.

  3. Wait 30 minutes.

  4. Start whitening treatment.

The 30 minute wait is a general recommendation since that appears to be how long it at least takes for your mouth to normalize. That duration is recommended for how long you should wait after having a meal before you should brush according to Columbia University.

Does fluoride interfere with whitening?

Rest assured, fluoride will not interfere with your whitening strips nor any bleaching treatment at all. We will provide you with three pieces of evidence to placate all concerns.

Whitening toothpaste with fluoride
Whitening toothpaste with fluoride

The most obvious answer is that the vast majority of whitening toothpastes contain fluoride. If your toothpaste can have fluoride mixed with the bleaching ingredient then surely brushing before using whitening strips should be okay. If it wasn't okay, then the toothpaste makers would remove all fluoride from their products.

opalesence boost in-office
opalesence boost in-office

The second answer is that there are some in-office whitening treatments which have fluoride in their bleaching gel. A prime example would be Opalesence Boost, which has 40% peroxide AND fluoride in it. If even at the dentist treatments utilize fluoride in it, your at home should be more than fine.

Lastly, there was a study which tested mixing sodium fluoride with hydrogen peroxide. There were no adverse effects reported and the teeth whitened normally. The hydrogen peroxide is the main whitening agent in all whitening products and it does so by oxidizing intrinsic stains.

Brushing after using whitening strips

You should brush your teeth after using whitening strips to desensitize and remineralize them but you should wait 30 minutes to do it.

Protocol for brushing after using the strips:

  1. Remove strips from teeth.

  2. Rinse out your mouth really well with water or baking soda.

  3. Wait 30 minutes.

  4. Brush your teeth for two minutes.

Desensitize the teeth

Tooth sensitivity is one of the two most common side effects from whitening. According to the ADA, sensitivity will typically start within 2-3 days after starting treatment with the strips.

The whitening sensitivity can be quite uncomfortable for some people which is why we recommend to use a desensitizing toothpaste afterwards. This type of toothpaste will help to reduce the discomfort after you take off the strips.

Types of desensitizing toothpastes:

  • Stannous fluoride based - Colgate Total; Crest Pro-Health; Sensodyne Rapid Relief

  • Potassium nitrate based - Sensodyne Pronamel; Colgate Sensitive

  • Hydroxyapatite based - Risewell; Dr Jen super paste; Wellnesse; Davids sensitive

You don't have to suffer through the teeth discomfort because you can start using a sensitivity toothpaste to alleviate the symptoms. Therefore, we highly recommend to specifically brush with a toothpaste that can lessen the discomfort after taking off the strips.


The toothpaste that you brush with should also possess the ability to remineralize the enamel in addition to decreasing the sensitivity. Remineralizing the teeth will help strengthen them after you've literally subjected them to a highly acidic whitening gel. Once they get remineralized, it will also help reduce the sensitivity as well.

When the enamel comes into contact with the bleaching gel it will start to demineralize, where it loses minerals. If you leave it as such, the tooth will begin to weaken over time.

demineralization remineralization of teeth
Credit: Sangi Co

However the process is often temporary because you can remineralize by adding minerals back into the enamel. This is typically accomplish by using a fluoride or hydroxyapatite based toothpaste. In essence, it will strengthen the weakened tooth structure.

Aside from making your teeth stronger, the remineralization process also desensitizes the teeth as well. The stannous fluoride and nano-hydroxyapatite can occlude the open dentinal tubules to reduce the sensitivity.

The reason you feel sensitivity is because the peroxide whitening gel dissolves and dislodges the smear plugs that were naturally occluding the tubules. With the tubules wide open, stimuli can enter or interact with the nerve endings unopposed.

Peroxide gel on smear plugs
Credit: KoR

Wait 30 minutes

Your teeth may feel sensitive immediately after taking off the strips but you shouldn't brush it right away. It is better if you wait 30 minutes prior to brushing them. You can rinse out with water but you shouldn't brush them.

Reason for waiting is because the whitening gel in the strips is highly acidic and right afterwards there will be residual acid on the enamel. If you brush your teeth immediately afterwards you will be rubbing acid into the enamel.

That can potentially be harmful because it may erode the enamel if you do that. What you want to do is rinse and then wait 30 minutes for your body to naturally neutralize the acid.

Typically after that half hour wait, it will be safe for you to brush your teeth. This principle also applies to why you shouldn't brush immediately after a meal. According to Columbia University, you should wait half an hour before you brush.

Therefore, regardless of if you were whitening or after you eat, you have to wait before you brush!


Our dentists in Long Island City recommend that you brush before and after using the whitening strips but you should wait 30 minutes in between both.

  • After brushing, wait 30 minutes before using the strips.

  • After whitening, waiting 30 minutes before brushing again.

The brushing before will give the strips a clean tooth surface to work on. The brushing after will help you decrease sensitivity and remineralize the teeth from the peroxide. If you're unsure you should schedule a dental consultation to have all of your questions answered.


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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