Does A Rotten Tooth Cause Bad Breath?

One of the most off-putting oral health problems is halitosis or bad breath. While there are different reasons why you might have this (poor oral hygiene, dry mouth, smoking, sugary foods, and illness), some wonder: Does a rotten tooth cause bad breath? The answer to that is yes. 

Badly decayed teeth are also referred to as rotten teeth. And while they may not directly contribute to a bad breath, it’s usually one of the symptoms of this problem. 

It’s important that you keep an eye out for such a problem because if left untreated, the decay might end up being too extensive. And that can even necessitate the extraction of the entire tooth. 

Also, if you have tooth decay, it can lead to gum disease or even dental abscess. And these can further exacerbate your halitosis. In this guide, you’ll learn more about why a rotten tooth makes your breath stink and what you can do to get rid of it. 

Why Does Tooth Decay Smell Bad? 

There are mainly two reasons why tooth decay can smell bad: 

  • Food particles are trapped and decaying within cavities 
  • Bacteria is breaking down the said food particles and releasing sulfur compounds 

Normally, after you eat something, food can get stuck between the teeth. It might be small enough for you to not see it. But before it even starts to smell, you might get rid of the food debris through brushing and flossing.

Teeth plaque

However, when you have poor oral hygiene habits, it can lead to the buildup of plaque, which can result in the formation of dental caries (another name for cavities). Once that happens, the food particles will have more spaces to get stuck in. 

Also, it might be difficult for your toothbrush to reach the deep end of the cavity fully. This can cause further damage to your teeth and can even lead to a painful infection. 

Here, you should note that if you have a dental abscess and it ruptures, that can also create a foul smell and taste in your mouth. Moreover, gum disease (which can result from tooth decay) can also give you a bad smelling breath. 

There is another scenario in which food may get trapped inside your mouth even when you have good oral hygiene: impacted wisdom teeth. 

It’s a situation in which the tooth’s either stuck or can’t get out because of lack of enough space. Because it makes them more difficult to clean, it’s easier for these teeth to get decayed. As a result, you might end up with a rotten wisdom tooth

Rotten wisdom tooth

What Does A Rotten Tooth Look Like? 

Extensive decay is the hallmark of a rotten tooth. In addition to causing halitosis, it can also cause pain and sensitivity. Your tooth can also have black, brown, or grey spots on it, indicating decay.

Rotten tooth

What Does Rotten Teeth Breath Smell Like? 

If you have bad breath due to food particles stuck within the tooth cavities, it can have a rotten and decaying smell (as the food is decaying). 

The bacteria, on the other hand, produce smelly sulfur compounds, which can smell like rotten eggs. According to a study published in the Journal of Natural Science, Biology and Medicine, with over 500 bacterial species in the mouth, most can produce stinky smells. 

But poor oral hygiene, in particular, allows such bacteria to flourish, which only exacerbates halitosis. 

How Do You Get Rid Of Bad Breath From A Rotten Tooth? 

To get rid of the bad breath from a rotten tooth, you need to get it checked by a dentist. Depending on the extent of your problem, you might need: 

In the case of an extraction, you might need a dental crown, bridge, implant or denture to replace the missing tooth as well. 

Other than that, it’s also very important for you to take care of your teeth by brushing twice a day and flossing to keep bad breath at bay. Also, make sure to clean your tongue, as that’s another place where sulfur-producing bacteria hang out in the mouth.

Oral hygiene

Keep in mind that eating loads of sugar food is going to be bad for your teeth, so you should cut down on that. And try to stay hydrated. If you have a dry mouth, you should consider chewing sugar-free gum as well. 

Lastly, make sure to visit your dentist regularly, at least twice every year (after 6 months). If the problem is caught early on, it will save you from undergoing extensive and expensive dental work. 

Will A Rotten Tooth Stop Smelling? 

If you have a tooth decay smell coming from your mouth, you must get an appointment with your dentist. If your rotten tooth is extensively decayed and is deeply infected, you can’t get it to stop smelling on your own. 

This odour is not permanent, however. Once your tooth has been cleaned and treated, you should stop having a bad smell. 


Rot is more often than not associated with bad smell. And just like with anything else, it’s possible for your rotten teeth to smell as well. But it’s not the tooth itself that will create the malodour. 

It can happen because of the entrapment of food debris in your cavities and the sulfur compounds produced by the bacteria in your mouth. This doesn’t mean you should take this problem lightly. 

If you have halitosis and it’s because of rotting teeth, you need to get treatment for it as soon as possible. Depending on how severe it is, you might just need a fluoride varnish, or your tooth may need to be extracted completely. 

If you’re also having issues with your teeth, make sure to get in touch with an experienced and qualified dental professional. 

Reviewed and approved by Dr Izbel Aksit 

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