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Why Do My Teeth And Gums Hurt After Flossing?

Person flossing lower teeth

Dental professionals recommend some form of daily interdental cleaning. You should do this as well as your brushing routine. 

The American Dental Association considers it to be an essential part of your cleaning regime.

Flossing is one type of interdental cleaning method – one way of cleaning between your teeth. Other options include using a water flosser or interdental brushes. For the sake of this article, flossing refers to any of these types of interdental cleaning.

Sometimes your gums can hurt after flossing. You could also experience some sensitivity after flossing. I will explain the most common reason for this, and what you can do about it.

Reasons your teeth or gums can hurt after flossing

Your Flossing Technique Isn’t Right

If you aren’t using the right flossing technique you can irritate the gums. Snapping floss between the teeth is one example of this. 

Poor technique will cause the gums to hurt after you have flossed as it traumatizes them.

Flossing requires some skill. Check your technique, and change it if needed. See our post on how to floss for more guidance.

With the right technique, you will clean the teeth and gums properly, without any irritation. 

After one or two weeks of correct flossing, the discomfort should go.

Person flossing lower teeth

You Have Gum Disease 

One of the most common reasons for your gums to hurt after flossing is that you have gum disease. This is also one of the most common causes for bleeding after flossing.

Gum disease (gingivitis) is inflammation of gums. These swollen gums are sore to touch, especially when cleaning.

The key to stopping the gums from hurting is to cure the gum disease. The most important factor is removing all the plaque from between your teeth. So persevere with flossing and the pain in your gums will improve.

Inside of teeth with some blood on gums

You Have Dentine Hypersensitivity

Dentine hypersensitivity is that short sharp pain you feel in your teeth. It can happen after eating or drinking something cold. Touching the tooth, for example with floss, can also cause the pain in your teeth.

Exposed dentine causes dentine hypersensitivity. Reasons for exposed dentine include gum recession and tooth wear.

If you have had gum disease in the past, you can have some gum recession. This normal healing process will expose sensitive parts of the teeth which were previously protected by the gums.

Tooth wear, such as by acids and over brushing can also remove the enamel layer of the teeth. This exposes the dentine underneath. 

Exposed dentine will be sensitive to changes in temperature and to touch.

You can manage sensitivity with a sensitivity toothpaste or mouthwash for sensitive teeth.

And prevent tooth wear worsening by using a toothbrush for receding gums.

You Have Dental Decay

Untreated dental decay can cause pain when flossing.

If you have dental decay you will notice pain in one particular tooth, when flossing in only one area. 

Dental decay leads to holes in your teeth. These holes expose the dentine layer of the teeth, and open up to the nerve of the tooth (pulp). Touching the tooth, for example with floss, will be very sensitive.

See a dental professional for treatment of dental decay.

Severely decayed front tooth
Image Source: Eureka Dental Group

You Have A Loose Filling

A loose filling can cause pain when flossing.

This is because the floss can move a loose filling. The dentine layer of the tooth is then exposed, and possibly even the nerve of the tooth (pulp). 

Exposing the dentine layer will lead to sensitivity when flossing. Irritating the nerve of the tooth can cause toothache after flossing.

Get the filling replaced and the problem will go away.

You Have Something Stuck In Your Gum

Getting something stuck in the gums will irritate them, making it sore when you floss.

It is common for small bits of food to become stuck underneath the gum. These aren’t a problem as they are normally removed quickly, using brushing and flossing.

But if it is left longer, the body will treat it like an infection and try to remove it. This leads to inflammation in that area. An inflamed area of gum will be sore to floss.

In particular, you might have pain between your teeth when flossing.

Thorough cleaning prevents this occurring and will also remove any trapped food. If this carries on for a few days without getting better despite good cleaning, see a dental professional.

You Aren’t Using The Right Floss

Not all floss is the same. It isn’t that one floss is better than another, just that you need the right one for you

Floss can be made from different materials, and in different ways. This can change the way you hold it and use it. It can also change the effect that the floss has on your gums.

If you can’t find an obvious reason for your gums to hurt after flossing, try changing the type of floss you are using. See our post on the best dental floss for a few suggestions.

You could also consider using a water flosser or interdental brushes instead. These are easier to use than floss. Research (which is discussed in my post here) has actually shown interdental brushes to be much more effective at cleaning between the teeth.

blue tepe, floss threader and floss pick next to each other

You Are Allergic To An Oral Hygiene Product

Your gums can have an allergic reaction to products. This is the same process as if your skin reacts to certain ingredients.

An allergy might show up as soreness after starting to use a new product. The irritated gums might also have ulcers on them.

This could occur if you have swapped toothpastes, for example. Try removing the new product from your cleaning regime and see if your symptoms improve.

If you have any doubt you should see a dental professional.

What to do if your teeth or gums hurt after flossing

Hopefully our reasons above have helped you figure out why your teeth or gums hurt after flossing.

So what should you do next?

Get Your Gums Healthy

Gum disease is the most common reason why you have a problem with flossing. Having gum disease can:

Get your gums healthy to overcome these problems. 

Gum disease is caused by plaque build up so cleaning is very important. General advice for keeping your teeth and gums healthy includes:

Don’t stop flossing if they are a little bit sore – it will get better with time. Usually within one to two weeks any pain with flossing will go away. You can see my advice on building a flossing habit here.

Check Your Flossing Technique

Make sure your flossing technique is right. Poor flossing technique can be ineffective – not removing all the plaque. If this is the case you won’t get the maximum benefit for how much effort you are putting in.

Poor flossing technique can also do some damage by irritating the gums. See our post on common flossing mistakes to know what to avoid, and see our video below on how to floss.

If string floss is not for you, consider switching to a different interdental cleaning product such as a water flosser or interdental brushes.

Use A Toothpaste For Sensitive Teeth

Sore teeth when flossing can be caused by dentine hypersensitivity. One of the things that can help is using a toothpaste specifically for sensitive teeth.

Sensitivity toothpastes include ingredients such as potassium nitrate or stannous fluoride which can reverse the symptoms of sensitivity. We discuss what’s in these toothpastes and have recommendations here.

Having the best toothbrush for receding gums will also prevent the cause of sensitive teeth worsening.

Get Your Teeth And Gums Checked

See a dental professional for regular checkups and cleaning to spot any potential problems early.

They will be able to tell you if there is dental decay or loose fillings before the stage where you get problems when flossing.

When to see a dentist

Sore gums are not unusual when you first start flossing. But how do you know when to see a dentist?

Don’t be concerned by mild discomfort in your first two weeks of flossing. This also applies to the first couple of weeks back after a break from a good oral hygiene routine.

See a dentist if you floss every day for a couple of weeks, but still have some discomfort when flossing. Same if you are getting bleeding when flossing.

Other reasons to see a dentist include:

  • You have something stuck in your gums that you cannot remove at home.
  • You think you have a loose filling or tooth decay.
  • When you have been flossing for a while and then gums become sore or start bleeding suddenly.

About Dr. Gemma Wheeler, BDS (Hons)

Gemma qualified from Cardiff University School of Dentistry in 2015. She went on to complete her Foundation Training and a further two years in the Armed Forces, primarily based around Wiltshire. She now works in a private practice in Plymouth.

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