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No More Sensitive Teeth After Whitening - My Easy Fix

Published or Updated On: 
December 16, 2022

Last time

A few years ago, I whitened my teeth. It was rough. By the end of the week, I was taking 800mg of ibuprofen every night before bed, living in fear of the next electric bolt of pain that would jet through my teeth, and dealing with a constant dull (or not so dull) ache.

I developed a pecilular sensitivity to sounds and feelings, particularly dry friction. Handling paper towel or cardboard was like nails on a chalk board. I was constantly putting lotion on my hands. Even mere thoughts could trigger pain and tingling, such as imagining the sound of the eraser on a pencil being used, but running out so the metal scrapes the paper. OOF!

I gave up shy of my whitening goals because I woke up one day and realized I was absolutely miserable. Given this history, you can imagine my excitement when my wife pointed out that our coffee and wine habits had caught up to us. And sure enough, after using a single Crest Whitening Strip, all of the same sensitivities started again. 

This time

Days later though, I have visibly whiter teeth with no pain or sensitivity. I’m knocking out multiple whitening treatments each day while drinking my favorite frozen protein shakes regularly. All pretty much pain & sensitivity free. How did I do it? First, let’s start with a little background on why whitening causes pain.

[Don’t care about why? Skip down to "The protocol" towards the bottom]

Why it hurts: long story short

No one is 100% sure, but what follows is the consensus as I understand it. Whitening products open up pores on your teeth in order to remove stains. This exposes an inner component of the teeth called dentin. When the exposed dentin comes into contact with external stuff like cold liquids or air, it triggers nerve pain. Whitening products can also cause mild pulpitis, which is a kind of inflammation inside the tooth.

The skinny on sensitivity

Sensitivity from teeth whitening is common. Somewhere around half of all whiteners will experience sensitivity. All good whitening products have the same cleaning ingredient: peroxide. The higher % peroxide, the higher likelihood of sensitivity.

Whitening products marketed as “sensitive teeth” are lower concentration & they advise you put them on for a shorter period of time. The stuff that claims to work faster is just a higher concentration. Your dentist might have a treatment that is super high concentration, like 40% peroxide (very high risk of sensitivity), while your everyday Crest 3D White Strips Professional Effects is around 6%.

Treat sensitivity with potassium nitrate

Potassium nitrate is a compound that interferes with nerve pain signals in the teeth. It’s the same drug that brands like Sensodyne put into some of their toothpastes to help relieve pain from sensitive teeth. It’s very effective at reducing pain from sensitivity. The problem is, if you’ve ever tried to use Sensodyne to get relief, you know brushing with it once doesn’t give you relief right away. Lots of guides online actually suggest starting something like Sensodyne two weeks before you start whitening to reduce the likelihood of pain. Ain’t nobody got time for that!

So what can you do instead? Buy a gel that is concentrated potassium nitrate, put it in trays for your teeth, and leave that shit on there. I can tell you anecdotally that this works, and here’s a study to back it up.

*Note: The gel linked above says remineralization, but it doesn’t do that. Let’s talk about that next

Remineralize with fluoride

As part of the “pore opening” process described above, whitening products may temporarily demineralize teeth. Demineralization is where your teeth lose minerals that are normally used to upkeep your enamel (the hard protective outer layer). Demineralization and remineralization is something that happens constantly throughout the day. For example, eating tends to demineralize, saliva later remineralizes. Temporary demineralization may be part of the equation for what causes pain when whitening. Over time, poorly mineralized teeth will result in weakened enamel. That’s bad.

You’ll remineralize on your own after whitening just by having spit in your mouth. But if you want to cover bases, it might be a good idea to give your teeth some extra TLC when whitening. Fluoride helps mineralize teeth. You can get the fluoride you need from many OTC toothpastes that include it as an ingredient. I used Sensodyne. Don’t bother with gels or other more expensive fluoride-based products you can find online, they frequently will have a similar amount of fluoride as an OTC fluoride toothpaste.

Rather than just brushing, I put some of the Sensodyne in my trays and popped them in for a bit, just as I did the potassium nitrate. I suspect this is better than just brushing. My wife has a prescription fluoride toothpaste & her dentist said it needs to be the last oral care product she uses (no water rinse!) because it needs to sit on the teeth. So in theory, I think trays should be even better. 

I’m not sure if this is step is needed, but it didn’t hurt & it might’ve helped. 

The protocol

The protocol itself is pretty simple. The main idea is to alternate potassium nitrate treatments with your whitening treatments.

1. Use the whitening product for manufacturer recommended period of time, then potassium nitrate gel for 45min

2. Repeat above as desired (I’ve done 4 White Strips treatments in 1 day without any pain or sensitivity - this is more than what Crest recommends but it caused no problems for me)

3. Throw in 1h of fluoride toothpaste in trays 1x per day while whitening

4. Wear your trays with potassium nitrate gel in in them overnight

It's unclear how long you need to have the potassium nitrate in to get relief, but in my experience, more time provided more relief. YMMV. Another important note is that I found relief from potassium nitrate trays lasted about 5-6 hours before the sensitivity/pain came back with a vengeance. This didn’t happen each day I whitened, but it did happen the first day I tried 4 whitenings in a day. I found the old adage to be true here, an ounce of prevention is worth a pound of cure. Easier to keep sensitivity away than get rid of it once it’s arrived.

I wouldn’t go wild with this on your first day just in case. If your gums start to get red, that’s a yellow flag.

A tip for application: if you’re using white strips, don’t pull them the strip apart too tightly when applying - you want it to be in full contact with the surface of your teeth. Just running your nail over each tooth (especially between) should do the trick. The strip needs to be in contact with the tooth.


Can I leave the whitener on for longer to make whitening go faster?

It depends on the product. For strips, the product likely has degraded peroxide concentration beyond whatever time the manufacturer recommends. So you might get some additional benefit, but not much. It’s better to just use a new strip. Crest says back-to-back is cool. For products like Opalescence where you’re choosing the amount you put in, keeping trays in longer may work - but at some point, you’ll have lost a lot due to saliva.

Can I take a day off between whitenings?

Yes. This will not hurt results. If you're still getting sensitivity, this is a good idea. Keep using potassium nitrate on your off days.

Can I use XYZ product instead?

Probably, all good whiteners have peroxide. But concentration matters. The more rapid whitening the product promises (e.g. 1h super sonic ultra bright extreme), the higher concentration it is and therefore the more likely you are to experience sensitivity.

Will using potassium nitrate affect my whitening results?

No. Study.

Do I need to follow a “white diet?”

No. Study.

Is this safe?

The smart thing to do is to talk to your dentist. I’m not a dentist, this is not medical advice blah blah blah don’t sue me. Crest says don’t use more than 2 of any of their kits per year. That seems like good advice. Don’t get silly with it. The brighter you try to go, the closer to the sun you’re flying. Don’t get burned. 

Will this hurt my enamel?

If you stick to 2 kits of Crest products per year or the equivalent for whatever brand you’re using, then probably not. In this study, they used 13% & 15% peroxide strips and left them on for 28 hours. No damage. Similar story here (70 hours!) and here.

If you see anything in this article that can be improved or corrected, email me and I’ll happily update.

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