Tooth decay causes the destruction of enamel, which is the hard outer surface of a tooth. As tooth decay progresses, it can attack deeper layers of a tooth, leading to cavities. Treatments can include fluoride, fillings, crowns, and more.

If a person does not receive treatment for tooth decay, it can lead to more issues with the teeth and mouth. However, some treatments can help prevent or stop the spread of tooth decay.

This article will cover the causes, symptoms, and treatments for a person with tooth decay.

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A person with tooth decay may experience sensitivity to sugary, hot, or cold food and drinks.

Tooth decay, also known as dental caries or cavities, is a disease that causes the breakdown of tooth enamel.

Once tooth decay has eroded the enamel, cavities can start to form.

According to the American Dental Association (ADA), a tooth consists of three layers:

  • Enamel: Enamel is the hard outer layer that protects the inner layers of a tooth. Tooth enamel contains no living cells and is the hardest structure in the human body.
  • Dentin: Dentin is the second layer of a tooth. When the enamel is damaged, it may expose the dentin. Small tubes within the dentin allow hot and cold food to stimulate the nerves of the tooth. The stimulation of these nerves can cause pain and sensitivity in the tooth.
  • Pulp: The pulp is the center of the tooth. The pulp contains blood vessels, nerves, and connective tissue.

Tooth decay can occur in varying degrees of severity. Damage from tooth decay can range from causing wear to the enamel to painful abscesses within the pulp of the tooth.

Symptoms of tooth decay can vary depending on the severity of the damage caused.

According to the National Institute of Dental and Craniofacial Research (NIDCR), some people in the early stages of tooth decay may feel no symptoms. However, as tooth decay advances, a person may experience the following:

  • tooth sensitivity to sugary, hot, or cold food
  • constant tooth pain
  • white or dark spots on the teeth
  • bad breath
  • loose fillings
  • cavities in teeth
  • food frequently trapped in teeth
  • difficulty biting certain foods
  • abscesses on teeth that cause pain, facial swelling, or fever

An article in the Journal of the American Dental Association (JADA) state that tooth decay occurs due to a buildup of plaque on a tooth.

Plaque is a sticky layer of bacteria that forms on teeth. When a person eats sugary or starchy food, the bacteria in the plaque produce acids that attack tooth enamel.

Over time, these acids leach out minerals from teeth, erode the enamel, causing tooth decay, and eventually, cavities.

Tooth decay can affect people of any age. The Center for Disease Control and Prevention (CDC) estimate that around 20% of children aged 5–11 years have at least one untreated decayed tooth.

Older adults may experience gum recession, which is where the gums pull away from the tooth, exposing the root of the tooth.

Cementum, which is softer than enamel, covers the root of the tooth. The ADA indicate that this may make the tooth more susceptible to decay.

A person may have a higher chance of developing tooth decay if they:

  • have a dry mouth
  • have weak enamel due to genetics or illness
  • do not brush their teeth twice a day with fluoride toothpaste
  • have an eating disorder, such as anorexia or bulimia
  • experience gastroesophageal reflux, also known as acid reflux, or GERD

A dentist will be able to recommend treatment for a person with tooth decay, depending on its severity.

Treatment for tooth decay can include:

Early-stage fluoride treatments

Fluoride is a mineral that can help strengthen enamel. A dentist can use fluoride in various forms to help stop and even repair the damage that has occurred due to tooth decay.

A dentist can apply professional fluoride treatments directly to the teeth.

These fluoride treatments are generally quick, taking only a few minutes. The fluoride comes in the form of a gel, varnish, foam, or solution.


When cavities occur from tooth decay, a filling can be a treatment option.

After drilling the tooth to remove any decay, the dentist shapes the cavity to fit the filling.

The dentist then fills the cavity, using materials such as dental amalgam or composite.


According to the ADA, larger cavities that occur due to tooth decay may require a crown instead of a filling.

To place a crown, the dentist first removes the outer portion of the tooth, as well as any decay.

The dentist will take an impression of the tooth and fit a temporary crown until the permanent one is ready for fitting, usually 1–2 weeks later.

Root canals

A dentist can perform a root canal to help prevent the need for extraction when the pulp of the tooth is damaged.

According to the American Association of Endodontists (AAE), the dentist first numbs the tooth before removing the pulp. They will then clean and shape the root canal inside of the tooth.

The dentist may also apply medicine in the tooth to get rid of any bacteria.

The dentist will then fill the root canals with a rubber-like substance and place a crown or filling on the tooth to restore and strengthen it.

Tooth extraction

A dentist may recommend a person has a tooth extraction if the tooth decay has caused severe damage.

The dentist will first numb the damaged tooth. Once they have removed the tooth, the dentist will recommend a post-extraction regime.

A person may notice swelling or pain after a tooth extraction, which is normal. However, if a person notices any of the following symptoms, they should call a dentist or seek medical attention immediately:

  • fever
  • nausea
  • vomiting
  • severe pain, swelling, or bleeding
  • pain that increases over time

According to the NIDCR, tooth decay, if caught in the early stages, is reversible. However, once the enamel of the tooth has lost too many minerals and the tooth has a cavity, it is unable to repair itself.

A dentist can treat damage and prevent it from spreading further.

A person can reverse tooth decay by cutting down on sugary and starchy foods and practicing good oral hygiene.

A person who suspects they may have tooth decay should visit a dentist.

The dentist may ask the person questions regarding any pain or symptoms. The dentist may also take an X-ray of the mouth to spot any cavities.

Once the dentist has diagnosed tooth decay, they will discuss further treatment options.

The NIDCR note that without treatment, tooth decay can lead to a variety of problems, such as:

Abscesses can cause potentially life threatening infections, such as sepsis.

A person with the following symptoms should contact their dentist immediately:

  • fever
  • tooth pain
  • tooth sensitivity to hot and cold
  • swollen gums
  • swollen lymph glands in the neck
  • swollen jaw

According to the National Health Service (NHS), in the United Kingdom, abscesses can also cause:

  • bad breath
  • an unpleasant taste in the mouth
  • pain that spreads to the ear, jaw, and neck

Tooth pain may also be worse when lying down and may wake a person up at night.

The ADA recommend that people can prevent or stop tooth decay by:

  • brushing teeth twice a day with fluoride toothpaste
  • limiting snacking
  • eating healthy, nutritious meals
  • asking a dentist about fluoride supplements
  • visiting a dentist regularly for checkups and professional cleaning

A person experiencing any pain or discomfort from their teeth should contact their dentist.

A person should also visit their dentist regularly for checkups to prevent decay.

Tooth decay is a widespread condition, with 9 out of 10 adults over the age of 20 having some level of tooth decay.

Tooth decay can vary in severity, and a range of suitable treatments are available.

A person who has symptoms of tooth decay should contact their dentist.

If left untreated, tooth decay can lead to tooth loss and more serious conditions.