Updated on February 9, 2024
7 min read

Rotten Teeth: Causes & Treatment

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What Do Rotten Teeth Look Like?

Tooth decay or dental caries can look like black or brown marks on your teeth. It occurs from plaque and acid buildup typically caused by poor dental hygiene. It’s also referred to as cavities or rotten teeth.

Plaque contains bacteria and is a sticky, colorless film that develops on the teeth. When these bacteria are mixed with sugars in food, they produce an acid that eats away at teeth. 

A decayed, rotten tooth can loosen and fall out if left untreated. To prevent this, it is essential to recognize the causes and symptoms of rotten teeth.

What are the Symptoms of Rotting Teeth?

Some cavities can go unnoticed with no symptoms, so it is essential to arrange regular dentist visits. A general dentist can treat cavities early to prevent further tooth rot.

An untreated cavity can become larger and eventually affect the deeper layers of a tooth. Aside from a hole, other symptoms of a rotten tooth include:

  • Tooth pain
  • Unpleasant taste in the mouth
  • Sensitivity to hot or cold temperatures
  • Brown, black, or white spots
  • Bad breath 
  • Swelling

6 Causes of Rotten Teeth

There are various causes of rotten teeth. Understanding what leads to decay can help prevent future oral health issues. If you are unsure why your teeth are decaying, see a dentist as soon as possible.

1. Poor Dental Hygiene

Poor dental hygiene is one of the most common causes of rotten teeth. Regular brushing and flossing are essential to remove plaque and keep your teeth strong and healthy.

Brush your teeth at least twice a day and floss daily. You should also visit your dentist twice a year for professional dental cleanings.

2. Bad Diet

A diet high in sugar and refined carbohydrates can contribute to tooth rot because these foods linger on the teeth. Sugar also feeds bacteria.

Without brushing your teeth regularly, the acid in your mouth can increase. It won’t be long before you’ll notice a faster breakdown of your tooth enamel.

Additionally, drinking too many acidic beverages such as soda and having acid reflux can lead to tooth decay. The acids can slowly dissolve tooth enamel.

3. Dry Mouth

If your salivary glands don’t create enough saliva to wash away plaque and bacteria, you may have more plaque and acid in your mouth.1 This increases the risk of rotten teeth.

Dry mouth is a potential side effect of a few factors, including:

  • Antidepressants
  • Antihistamines
  • Cancer treatment

4. Dental Crevices

Tooth rot can also develop if you have deep dental crevices. These grooves can make it more challenging to brush your teeth effectively.

If plaque lingers in these grooves, it can eat away at your tooth’s surface. Consider asking your dentist to apply a dental sealant to your teeth to prevent plaque buildup.

5. Fluoride Deficiency

Fluoride is a natural mineral. It can strengthen your tooth enamel, making it resistant to decay. 

Fluoride is mixed with public water supplies but is not usually found in bottled water. If you do not use fluoride toothpaste or drink from your local water supply, there is a risk of tooth decay.

6. Baby Bottle

Tooth decay can also develop early if your child falls asleep with a bottle of milk, formula, or juice in their mouth. It can also occur if you dip your child’s pacifier in sugar or honey. In both circumstances, sugar can gather around the teeth and contribute to rot.

Treatment Options for Rotten Teeth

The treatment for rotten teeth is usually the same for adults and children. Saving the tooth is the treatment goal.

Treatment for Early-Stage Tooth Rot

Your dentist may use a fluoride treatment in the early stages of tooth rot, including small cavities. This can strengthen or remineralize the tooth. 

However, this method only works for smaller cavities and is ineffective once other rotting signs develop. For example, dark or white spots on the tooth and bad breath.

Treatment for Advanced-Stage Tooth Rot 

When fluoride treatment is not an option, your dentist may remove decayed parts of the tooth. They will place a dental filling or dental crown to fill any holes in the tooth.

3D illustration of a Temporary Dental Crown being installed on to teeth

For a filling, your dentist typically uses a tooth-colored composite resin. Or, they may use an amalgam filling like mercury, silver, or other metal. Amalgam fillings are typically only placed on baby teeth.

Treatment for Extremely Advanced-Stage Tooth Rot

You may require a root canal if the decay has spread to the middle of the tooth and there is inflammation or an infection. Root canals remove the infected nerve and pulp.

Once the infection has been removed, they’ll fill and seal the space. If a tooth can’t be saved because of severe rot, your dentist may extract it and replace it with: 

  • Bridges
  • Dentures
  • Implants

When Should You See a Dentist?

A dentist will be able to see the early signs of cavities and other dental problems. If you experience one or more symptoms of tooth decay, see a dentist immediately.

It may be challenging to know if you have a cavity. This is why it’s important to have regular dental checkups and cleanings.

Who is at Risk of Rotting Teeth?

Over the years, teeth can wear down, and gums may recede. This makes teeth more vulnerable to root decay.

People at risk of tooth decay include:

  • Young children
  • Teenagers
  • Older adults
  • People who take medications that reduce saliva flow

Rotten Tooth Symptoms in Children

Symptoms of a rotten tooth for children are generally the same for adults. However, they may experience other symptoms, such as:

These symptoms indicate an infection. If your child seems irritable and cannot demonstrate the location of the pain and discomfort, check inside their mouth for signs of tooth rot. 

Risks and Complications of Rotten Teeth

Cavities and tooth decay can have severe and lasting complications, even for children who do not yet have permanent teeth.

Close up shot of 3d render human teeth with focused hole on tooth due to cavities

Risks and complications of rotten teeth may include:

  • Pain
  • Swelling or pus surrounding a tooth 
  • Damage or broken teeth 
  • Chewing issues 
  • Positioning shifts of teeth following tooth loss

Severe Side Effects of Tooth Decay

When decay becomes more severe, you may experience:

  • Pain that interferes with daily living 
  • Weight loss or nutrition issues from painful or difficult eating or chewing 
  • Tooth loss

In rare circumstances, a tooth abscess may develop. It’s a pocket of pus caused by bacterial infection. A tooth abscess can lead to more severe or life-threatening conditions like sepsis. 

Can You Reverse a Rotting Tooth?

The earliest stages of tooth decay can be stopped or reversed. One of the signs of this early stage is a white spot on your teeth where minerals have been lost.

Tooth enamel can repair itself using minerals from various sources, such as:2 

  • Saliva
  • Fluoride from toothpaste
  • Silver diamine fluoride

How to Prevent Teeth From Rotting

You can prevent rotten teeth by maintaining good oral and dental hygiene. It also helps to visit your dentist regularly to prevent other dental health conditions from developing early on.

Here are some tips you can follow to avoid rotten teeth:1

  • Brush your teeth at least twice daily (ideally after every meal) with fluoride toothpaste 
  • Floss or use an interdental cleaner to clean between your teeth
  • Get professional teeth cleaning treatments and regular oral exams to help prevent issues or spot them early
  • Use a mouth rinse with fluoride if your dentist thinks you have a high risk of developing cavities
  • Consider using dental sealants to seal off crannies and grooves that typically gather food


Rotten teeth are caused by plaque and acid buildup in the mouth. If left untreated, a decayed tooth can loosen and fall out.

Tooth decay is often caused by poor oral hygiene. However, other factors can cause tooth decay, such as high sugar diets, fluoride deficiencies, and dry mouth.

You can prevent tooth decay by practicing good oral hygiene and visiting your dentist at least twice a year. Your dentist may perform a fluoride treatment, dental filling procedure, or root canal to treat tooth decay.

Last updated on February 9, 2024
6 Sources Cited
Last updated on February 9, 2024
All NewMouth content is medically reviewed and fact-checked by a licensed dentist or orthodontist to ensure the information is factual, current, and relevant.

We have strict sourcing guidelines and only cite from current scientific research, such as scholarly articles, dentistry textbooks, government agencies, and medical journals. This also includes information provided by the American Dental Association (ADA), the American Association of Orthodontics (AAO), and the American Academy of Pediatrics (AAP).
  1. Cavities/tooth decay.” Mayo Clinic, 2017.
  2. The Tooth Decay Process: How to Reverse It and Avoid a Cavity.” National Institute of Dental and Craniofacial Research, 2018.
  3. Tooth decay: Overview.” Institute for Quality and Efficiency in Health Care (IQWiG), 2020.
  4. Heng, C. “Tooth Decay Is the Most Prevalent Disease.” Federal practitioner: for the health care professionals of the VA, 2016.
  5. Fiorillo, L. “Oral Health: The First Step to Well-Being.” Medicina (Kaunas, Lithuania), 2019.
  6. Sälzer et al. “Contemporary practices for mechanical oral hygiene to prevent periodontal disease.” Periodontology 2000, 2020.
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