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Updated on February 3, 2023
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Rotten Teeth: Causes & Treatment

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What Do Rotten Teeth Look Like?

Poor dental hygiene can put you at risk for tooth decay, otherwise known as a cavity or rotten tooth. Tooth decay occurs from plaque.

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

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

Medical Images of Tooth Decay

134117 mouth with severe tooth decay
Depositphotos 14363891 xl 2015

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

Consuming a diet that is 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 do not create enough saliva to help 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 also 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 enamel, making it resistant to decay. 

Fluoride is mixed with public water supplies, but it 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.

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:

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

Rotten tooth symptoms in children are generally the same as those in adults but may also include:

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. 

Who is at Risk of Rotting Teeth/Tooth Decay?

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

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.

Risks and complications of rotten teeth may include:

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

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
  • Tooth abscess

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

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

In the early stages of tooth rot, including small cavities, your dentist may use a fluoride treatment to strengthen or remineralize the tooth. This may reverse a cavity. 

However, this method only works for smaller cavities and is not effective once other signs of rotting 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 a dental crown to fill any holes in the tooth.

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.

Your dentist removes the infected nerve and pulp. Then they fill and seal the space.

When a tooth cannot be saved because of severe rot, your dentist may extract the tooth and replace it with a bridge, denture, or implant. 

Can You Reverse a Rotting Tooth?

Early 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.

Enamel can repair itself using minerals from saliva, fluoride from toothpaste, silver diamine fluoride, and other sources.2

How to Prevent Teeth From Rotting

Good oral and dental hygiene can help you prevent teeth from rotting. Here are some tips: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
  • Visit your dentist regularly
  • 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 a buildup of acid in the mouth
  • It is possible to reverse tooth decay during its early stages
  • Poor oral hygiene is one of the most common causes of tooth rot
  • Your dentist may perform a fluoride treatment, dental filling procedure, or root canal to treat tooth decay
  • You can prevent tooth decay by practicing good oral hygiene and visiting your dentist at least twice a year
Last updated on February 3, 2023
6 Sources Cited
Last updated on February 3, 2023
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, July 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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