How Long To Leave Fluoride Varnish On Teeth

Written & Reviewed by Dr David Chen

Fluoride varnish is a type of fluoride treatment, which is applied to your teeth in the form of a sticky gel. Once it comes into contact with saliva it will start to harden and you’re suppose to leave it undisturbed for maximum effect.

duraflor ultra - fluoride varnish box with individual dose packet

If you eat too soon or brush it off, you won’t be reaping the maximum benefit that you could’ve gotten from this fluoride treatment. This is why it is important to understand how long you’re supposed to leave the fluoride varnish on before doing anything. If you remove it too soon you may have wasted your treatment and also the money that you spent on it.

How long does fluoride varnish need to stay on?

The average time that the fluoride varnish needs to stay on is about 2-6 hours after application. There is a range because each brand or manufacturer has a different recommended time for treatment.

We will review four different brands so you can have an idea about how long you should expect it to stay on. Although the best thing to do would be to ask your dentist directly because they have the instructions from the manufacturer. We don’t know which one they used so we can only give you an estimate based on what we see.

Nonetheless with that being said, it is beneficial to leave it on for as long as possible. In fact, it is even better if you can leave it for longer than the stated duration of time because the fluoride keeps on working.

However we do understand that it may be difficult to go an entire day without eating. That is why we believe the brands of varnish advise a time restriction closer to in between meal times.

Premier Tastytooth Varnish

The instructions for Premier’s Tastytooth fluoride varnish states it should remain on the teeth for approximately 4-6 hours. That is a fairly long time!

Tastytooth fluoride varnish

Other instructions during the 4-6 hour treatment period:

  • Do not brush and floss during that time.
  • Eat a soft food diet.
  • Avoid hot beverages and alcohol

Embrace Varnish

The instructions for the fluoride varnish by Embrace says that it should stay on the teeth for 4 hours or longer.


We find it absolutely fascinating that this product only has a minimum time requirement but no maximum one. You should leave it undisturbed for at least 4 hours but you can technically leave it on for as long as you want. The longer it stays on the stronger your teeth will get.

Another interesting point is that there are no directions in regards to eating, drinking, or brushing. It is nowhere to be found on their instruction sheet.

Medicom Duraflor

The Medicom Duraflor fluoride varnish needs to stay on the teeth for 2-4 hours, which is according to their instructions.

medicom fluoride varnish

Other instructions for the 2-4 hour treatment period:

  • You ARE allowed to eat soft foods and cool drinks immediately after application.
  • You are NOT allowed to drink hot beverages like hot coffee during the treatment period.

3M Vanish

The instructions for the 3M Vanish states the fluoride varnish should remain on the teeth for at least 4 hours.


Other instructions by the manufacturer:

  • You’re permitted to eat and drink immediately afterwards but stick to soft foods and cool beverages.
  • Avoid hot drinks like coffee and alcoholic beverages.
  • Do not brush or floss your teeth during the 4 hour treatment period.

This one is similar to the Duraflor in that you can eat and drink right after the treatment is applied. However this particular product also specifically says that it is preferable to not brush and floss your teeth for a full 24 hours.

It seems like you can brush after the 4 hour treatment time but it is even more beneficial if you can wait a full day prior to doing so.

How long after fluoride varnish can I eat?

Unfortunately the answer for when you can eat after fluoride varnish would be that it depends. There is no clear cut answer because every brand is different. Some of them says to wait until after the treatment period ends which is anywhere from 2-6 hours.

yogurt with strawberries

However there are some which specifically say that you can eat and drink immediately afterwards. Although if you do choose to do so, you should stick to softer foods. You should also avoid hot beverages along with alcoholic drinks.

In regards to this, it would be best to ask your dentist directly. You should do your best to follow the manufacturer’s instructions.

What about drinking?

Some of the fluoride varnishes do not permit drinking during the treatment period. Although there are others which do permit drinking beverages immediately afterwards but only if they are cool or room temperature.

glass of milk next to metal jug

Even the ones that do allow drinking, they explicitly forbid drinking hot beverages such as coffee. That means if you wanted your cup of joe, you should’ve drank it before the dental appointment. If you didn’t do that then you’ll have to wait the full specified time prior to doing so.

When can I brush my teeth after the fluoride treatment?

All of the fluoride varnish brands advise to avoid brushing and flossing your teeth during the stated treatment period. You should wait to do so because the brushing can remove the varnish from your teeth. That is counterproductive because you want it to stay on your teeth so that you can reap the maximum benefit.

The instructions say that in order to fully remove the residue from the fluoride varnish you should brush. In other words, it is the last thing that you want to do.

However we do want to point out that there was one particular brand of varnish which says it was preferable to not brush for a full 24 hours. What that implies is that the product actually continues to work past the treatment time. If you wanted the most out of your treatment, you can consider not brushing your teeth that night!

The benefits of leaving fluoride varnish on

In case you wanted to know why you should even bother trying to maximize this product’s effects, it can prevent cavities and decrease teeth sensitivity.

Studies have shown that fluoride works via a topical mechanism:

  • Inhibition of demineralization at the crystal surfaces inside the tooth.
  • Enhancement of remineralization at the crystal surfaces (the resulting remineralized layer is very resistant to acid attack).
  • Inhibition of bacterial enzymes.

Those are all wonderful benefits but another one is that it can actually be used to treat dentin hypersensitivity. Apparently the effects are long lasting, even up to 8 weeks.


On average, fluoride varnish should stay on your teeth for anywhere from 2-6 hours. You should try your best to not brush or floss during that time. However there are some varnishes which do permit you to eat and drink during that period. Although you can only eat soft foods and non-hot beverages.

It really all depends on what the fluoride varnish’s manufacturer says. It would really be the most accurate if you can ask your dentist! However it doesn’t hurt to just leave it undisturbed for about 4 hours if you can.


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