All About Tooth Decay: Signs, Causes, Treatment, and Prevention

Medically Reviewed By Christine Frank, DDS
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Tooth decay is a process in which acids and bacteria target and deteriorate the surface of your teeth. Tooth decay is common in cases of poor oral hygiene and excessive sugar consumption.

If you have tooth decay, you may experience pain or excessive sensitivity while eating or drinking certain things.

If you experience symptoms of tooth decay, you may want to contact your dentist as soon as possible.

This article explains what tooth decay is, what it can feel like, how to treat it, and how to prevent it.

What is tooth decay?

a man is brushing his teeth
Ivan Gener/Stocksy United (person appearing is a model and used for illustrative purposes only)

Tooth decay, also known as dental caries, is the process in which the exterior layer of your tooth wears away. 

Bacteria target the enamel, which is the hard outer layer of the tooth, and cause its destruction. This is called a cavity.

Who usually gets tooth decay?

Tooth decay can affect everyone. Children and adolescents are generally more at risk.

It is also more common in people who consume sugar regularly, particularly in the form of sweet, sticky foods that you may consume between mealtimes. 

What are the signs of tooth decay?

You may not experience any symptoms of tooth decay at first. Your dentist may spot a new cavity forming during a checkup or while looking at X-rays.

If you have tooth decay, you may experience the following symptoms:

  • toothache
  • tooth sensitivity to sweet, hot, or cold foods
  • white or brown stains on the tooth’s surface
  • a hole in your tooth
  • an abscess, which is a type of infection (a pocket of pus) that can cause fever, swelling, and pain

Learn about dental caries here.

Is tooth decay serious?

Tooth decay treated during its early stages is not serious. 

Without treatment, however, tooth decay can get worse. In the most severe cases, tooth decay can cause an abscess.

Your dentist may need to extract the affected tooth.

When should you contact a dentist?

If you feel discomfort or present any signs of tooth decay, you should contact your dentist to book an appointment. 

It is important to treat your tooth as soon as possible to prevent the progression of the decay.

What causes tooth decay?

The three major causes of tooth decay are:

  • plaque
  • poor oral hygiene
  • eating a lot of foods with high sugar content

Plaque covers the enamel of your teeth, and it starts forming about 20 minutes after a person eats food. Bacteria, saliva, and food particles compose plaque.

When you eat, bacteria break down food and the sugar present in it. This process creates acids that stick to your teeth.

If you do not clean your teeth after you eat, the acid will target the enamel coating of your tooth and start destroying it. This process enables bacteria to pass the hard outer protection of your tooth and gives them the opportunity to affect the inner part of it.

Learn how toothpaste works to clean teeth here.

How do you treat tooth decay?

According to the severity of the tooth decay, there are several possible ways to treat it. These include:

  • fluoride treatments
  • fillings
  • a root canal
  • extraction
  • crowns

During the early stages of the decay, a fluoride treatment can help the tooth repair itself.

If the tooth decay arrives at the stage of a cavity, the dentist can fix the problem by cleaning the decayed tooth tissue and filling the cavity with a filling material to restore your tooth’s shape.

If the tooth decay has affected the pulp, which is the inner part of your tooth, the dentist may need to perform a root canal. They will remove all of the decay and the affected pulp, clean and seal the root of the tooth, and install a temporary filling.

You may need to visit your dentist a second time to replace the temporary filling with a permanent one or a crown, depending on the location of the tooth.

In the most serious cases, your dentist may need to pull your tooth. This may be the case if they cannot fix the pulp damage or if too much of the tooth structure has been destroyed.

In these cases, your dentist may suggest that you get an implant or a bridge to replace the missing tooth. This can help prevent the movement of the now narrower teeth after the change of your bite.

Can you fix tooth decay permanently?

If you have tooth decay, you can fix it by visiting your dentist. They can treat it and stop it.

There are also many tips and lifestyle habits that can help you prevent tooth decay from developing in the first place.

How do you prevent tooth decay?

There are several ways to prevent tooth decay, including:

  • brushing your teeth using a fluoride toothpaste twice per day
  • flossing
  • avoiding sugary snacks between meals
  • avoiding sugary drinks before bedtime
  • limiting the consumption of fizzy drinks
  • drinking tap water, which contains fluoride
  • staying hydrated
  • chewing sugar-free chewing gum after meals to increase saliva
  • using dental sealants

The keys to preventing tooth decay are: 

  • eating and drinking healthy foods and beverages
  • keeping yourself hydrated, as saliva is very important for your mouth’s general health
  • maintaining good oral hygiene to prevent the spread of bacteria and plaque in your mouth 

Learn more tips for good oral health here.

How do professionals diagnose tooth decay?

It is possible to diagnose tooth decay during a dental checkup. 

Your dentist may notice the presence of some white spots on your teeth. This usually indicates that some decay has started but that it is still in the early stages.

The dentist may also see some darker or black spots that are signs of tooth decay in a more advanced stage.

X-rays can also help during the diagnosis of tooth decay. They help your dentist judge the internal health and integrity of the tooth.


Tooth decay usually occurs as a result of poor oral hygiene alongside excessive sugar consumption. 

Bacteria create acid while they break down food. This acid targets the outer layer of your tooth and creates holes through which bacteria can infiltrate and affect the inner part of your tooth.

You may not experience any symptoms of tooth decay. However, your dentist can diagnose it during a checkup or by consulting X-rays.

It is a good habit to brush your teeth after you eat a meal to prevent bacteria from creating acid and to keep your mouth healthy. It is also best to restrict the amount of sugar you consume.

If tooth decay occurs, it is possible to stop it and treat it. Depending on the seriousness of the decay, your dentist may need to extract your tooth if they cannot repair the damage in other ways.

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Medical Reviewer: Christine Frank, DDS
Last Review Date: 2022 Jul 28
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.