Do You Brush Your Teeth Before or After Whitening Strips?


Teeth whitening is the most popular topic I discuss with my patients in my dental chair. I go over all the instructions of use regarding teeth whitening strips with my patients who are interested in using them. One of the most critical instructions I give my patients is the instructions for brushing teeth before and after whitening strip use.

Floss and brush your teeth without toothpaste before applying whitening strips to your teeth to remove food debris and bacteria that can hinder product effectiveness. Brush teeth with fluoride toothpaste and potassium nitrate after treatment to ensure remineralization and prevent tooth sensitivity.

Photo of tooth whitening strips product by HiSmile
HiSmiles newer teeth whitening strips that use PAP. You can learn more about them in this post I wrote here.

The effectiveness of the teeth whitening treatment can be significantly affected by how we prep our teeth and aftercare. In this post, I go over all the instructions for teeth whitening that I give my patients and what I do myself when I use teeth whitening strips!

Why do you need to brush without toothpaste before teeth whitening?

Cleaning the teeth and removing food debris and bacteria is crucial to get a good result from teeth whitening.

Brushing without toothpaste before applying tooth whitening strips will allow the active whitening ingredient to have the best results possible because the tooth will be more receptive. Ingredients in the toothpaste will prevent absorption of the teeth whitening ingredients.

Also, brushing and flossing will remove food debris and plaque, and if the teeth are not cleaned before applying the teeth whitening strips, it will prevent the active ingredients in the product from having even and direct contact with the tooth.

The active ingredients may not penetrate areas where food debris and plaque are present on the teeth, ultimately reducing the effectiveness. You may even get a blotchy appearance where some areas are whitened and others are not.

I just want to note that I am only talking about not brushing with toothpaste immediantly prior to applying tthe teeth whitening strips, not on a regular basis! 

I tell my patients not to use toothpaste because the toothpaste leaves a layer on the tooth to strengthen the teeth and protect against acid erosion.

Again, the toothpaste layer on the teeth can prevent the active ingredient in the whitening strips from penetrating the tooth’s surface to oxidize the stain molecules.

Preventing the product from entering the tooth surfaces will make it less effective. I don’t want you to waste your money.

I want you to get the highest value and effectiveness from the product you use.

The best product on the market for at-home teeth whitening is Crest Whitestrips. I will link them here on Amazon Opens in a new tab.if you want to see which ones I use and recommend to my patients.

Instructions by a dental hygienist for applying teeth whitening strips

Applying teeth whitening strips properly to the teeth affects how effective whitening the teeth is.

1. Floss and brush without toothpaste

After flossing and brushing without toothpaste, your teeth will be a clean slate free of bacteria and food debris. This is a crucial step to ensure the effectiveness of the product.

2. Dry your teeth immediately before applying the strip to your teeth

Before applying the teeth whitening strip to the teeth, you want to make sure your teeth are dry. Saliva on the teeth will prevent the teeth whitening strip from adequately adhering to the teeth, reducing the effectiveness.

If saliva is present, it also increases the change of product migration and chances of the active ingredient coming into contact with the gum tissue and potentially causing injury to the gums and entering your bloodstream.

The bottom teeth will be harder to dry than the top because we have a sizeable salivary gland underneath the tongue, and the saliva will pool to the front of the mouth due to gravity.

I apply the teeth whitening strip to the bottom teeth first because I find that applying the top one triggers my salivary glands to produce more saliva, making it more difficult to apply the strip to the bottom teeth. 

When I apply the whitening strips to my teeth, I push my lips out of the way and use a piece of gauze or paper kitchen towel to absorb saliva.

3. Read the instructions and keep the product on the teeth for the indicated time

Different products use different strengths of the active ingredient so make sure to read the label and instructions for use that are specific to the product you are using.

Some products may require a 15-minute application time, and others may require 1 hour.

When I recommend teeth whitening strips to my patients, I always advise them to use a product worn for the least amount of time.

A product worn for the least amount of time indicates that it contains a higher percentage of the active ingredient. This is important because the higher percentage of the active ingredient means it will penetrate deeper into the tooth vs using a product will a lesser percentage.

You want to reach as deep into the too as possible because it will provide a superior whitening result.

Set a timer on your phone, or watch the clock to ensure you have reached the desired time.

4. After indicated application time is done, remove strips from the teeth

Peel off the whitening strips from your teeth and throw them out after the time of application is up. Make sure not to swallow before brushing your teeth. After touching the whitening strip, wash your hands as you don’t want to get any of the product on your clothing or elsewhere.

Sensodyne Fresh Mint toothpaste

5. Brush your teeth with toothpaste and floss

You want to ensure you remove all the product from your teeth. Brush your teeth for a full 2 minutes with fluoridated toothpaste.

Use a toothpaste containing potassium nitrate for extra protection and tooth sensitivity prevention. Potassium nitrate desensitizes the tooth’s nerve, preventing the pain signal from reaching your brain.

Teeth can get quite sensitive after teeth whitening, and zingers can occur (short, intense periods of pain in the teeth). Here is a post linked below I wrote on how to prevent and stop zingers and teeth sensitivity associated with teeth whitening!

Read Now: Teeth Whitening Zingers: How to Prevent or Stop Sensitivity

And preventing sensitivity is the best way to manage pain. For two weeks before beginning teeth whitening treatment, use the toothpaste I linked below to help prevent painful tooth sensitivity!

It is important to note that you should not rinse/eat/drink for 30 minutes after use for the most effective outcome. All you need is a pea-sized amount of toothpaste, and spit out the excess after brushing for 2 minutes.

What I use myself and I recommend to my patients is the Original Fresh Mint Sensodyne which you can find on AmazonOpens in a new tab. because it contains potassium nitrate and fluoride.

6. Avoid pigmented food and drinks after teeth whitening treatment

You want to avoid anything with pigment for at least a couple of days after the teeth whitening treatment is complete.

Rule of thumb I tell my patients; Anything that will stain a white shirt will stain your teeth. 

I wrote an entire resource linked below with food examples about what foods and drink to avoid during and after teeth whitening!

Read Now: Teeth Whitening: Foods and Drinks to Avoid During and After

Teeth whitening dehydrates your teeth, making the teeth act like a dry sponge. The teeth will absorb pigment at a much higher rate after teeth whitening.

How long after teeth whitening can you consume pigmented food?

It can take a couple of days for the teeth to rehydrate fully, and why I tell my patients to wait that time.

However, I know for some people, it is unavoidable. So if they really need a cup of coffee, I say to drink it as fast as they can and rinse their mouth out with water after, rinsing away the pigment before it can be absorbed into the teeth.

A cup of chai. Tea can stain teeth, especially after teeth whitening.

7. Complete treatment in a timely manner

You want to complete the treatment as directed on the packaging. You do not want to whiten two times a week, take a month’s break, and then do another two days. The treatment needs to be consistent, not only for effectiveness and to get the best-desired result. Misusing teeth whitening can damage the tooth surface or restorations such as fillings.

However, I tell my patients that if they get the desired shade of tooth before using up all the strips, they can stop using them. But in saying so, you do not want to use them intermittently. Intermittent use will reduce the effectiveness and be a waste of time, effort and money.

Other information you need to know about using teeth whitening strips

Do not overuse teeth whitening strips

I had a patient once who was chronic teeth whitener and used Crest Whitestrips daily. I explained to her all the risks, but she just kept using them. There is still not much long-term evidence to show precisely what teeth whitening can do to the teeth long term.

Follow the instructions for the time to keep them on your teeth

Make sure to check the package for instructions for use. Some whitening strips need to be on longer than others to achieve the best result.

Have a dental cleaning before using teeth whitening strips

Calculus (also known as tartar) can build up on the teeth and make the teeth appear more yellow. Calculus cannot be removed at home and needs to be safely removed by a licensed dental professional. Having teeth cleaning right before teeth whitening will allow a clean surface, and teeth whitening will be more effective.

Consult a dental professional for tailored advice before using (do you have dental work on front teeth?)

Restorations will not whiten. Crowns, veneers, fillings; any fake tooth surface will not be affected by teeth whitening products.

Do not use intermittently

As I previously mentioned, you want to use this product consistently until you are done with treatment. Please do not use it for two days; skip a month and do another two days.


I hope you find this information useful and get the best results with teeth whitening!

Holly 🙂

Holly Verran RDH

I have been a Registered Dental Hygienist in Ontario, Canada, since 2014. I currently hold registration and good standing with the College of Dental Hygienists of Ontario and the Canadian Dental Hygiene Association.

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