Tooth Decay

People of all ages can develop tooth decay, from childhood through older life. It is treatable and largely preventable.

Overview

Tooth decay is one of the most common chronic diseases in children and adults. Yet it is largely preventable. Tooth decay begins when bacteria in your mouth release acids that dissolve minerals in the tooth’s outer surface, called enamel. When a tooth is repeatedly exposed to acid, the enamel continues to lose minerals, which can lead to a small hole, or cavity, in the tooth. Left untreated, tooth decay can cause pain, infection, and even tooth loss.

Untreated tooth decay rates have declined over the past several decades for most Americans. However, tooth decay is still a very common experience, and significant differences in treatment rates remain among some groups.

Related Terms: Cavities are also called dental caries.

Signs and Symptoms

People of all ages can develop tooth decay, from childhood through older years.

When tooth decay begins, there are usually no symptoms. A white spot on the tooth is often an early sign of decay that appears due to loss of minerals. As decay advances, it can cause:

A toothache or tooth pain
Tooth sensitivity to sweet, hot, or cold foods and drinks
A visible hole or cavity

Untreated tooth decay can cause additional harm. It can lead to:

Pain, infection, and tooth loss
Abscesses, which are painful pockets of pus: This can lead to facial swelling and fever

Causes and Risk Factors

Tooth decay begins as a slow and gradual process. Our mouths are naturally full of different types of bacteria. Some bacteria are helpful. But others can be harmful, including some that use sugar in food to make acids.

When decay-causing bacteria come into contact with sugar from foods and drinks, they produce acid. This acid can dissolve the minerals in tooth enamel. When a tooth is repeatedly exposed to acid, such as when you frequently consume food or drinks that are high in sugar, the enamel continues to lose minerals. Enamel can repair itself by using minerals from saliva, fluoride in toothpaste, or other sources. But if more minerals are lost than can be restored, the enamel weakens and eventually breaks down, forming a cavity.

Even teeth that already have fillings are at risk, because plaque can build up underneath a chipped filling and cause new decay.

If gums pull away from the teeth (called gum recession), the exposed tooth roots can decay as well.

Factors that contribute to tooth decay include:

Consuming food and drinks high in sugar throughout the day or after brushing your teeth at night.
Using tobacco products. People who currently smoke are more likely to have untreated tooth decay.
Having dry mouth, which reduces saliva and increases the risk of tooth decay.
Social, economic, and geographic obstacles that limit access to regular dental care.

Prevention Guidance

The good news: tooth decay is largely preventable. Here are important steps you can take.

Practice Good Oral Hygiene

Brush your teeth twice a day with a fluoride toothpaste.
Floss regularly to remove plaque from between teeth. Or use a specialized brush or wooden or plastic pick recommended by a dental provider.
Replace your toothbrush when the bristles become worn.

Use Fluoride

Fluoride is a naturally occurring mineral that can keep tooth decay from progressing and even reverse or stop early decay. Fluoride works by:

Strengthening the tooth’s hard outer surface, called enamel
Reversing early tooth decay by replacing and preventing the loss of minerals that make teeth healthy
Stopping the growth of bacteria that cause cavities

You can get fluoride by:

Using a fluoride toothpaste or mouth rinse
Drinking tap water in communities where the public water system monitors and regulates fluoride levels
Getting a fluoride varnish or gel applied by a dentist

Make Smart Food Choices

Eat nutritious, balanced meals and limit snacking.
Only sparingly eat candy, cookies, soda, and other sugary drinks.
Limit snacking in between meals to reduce the number of acid attacks on teeth and give teeth a chance to repair themselves.
Do not eat or drink anything with sugar after evening tooth brushing.

See a Dentist Regularly

Visit a dentist regularly for cleanings and an examination. During the visit, the dentist or hygienist will:

Remove dental plaque
Check for any areas of early tooth decay
Show you how to thoroughly clean your teeth
Apply a fluoride gel or varnish, if needed

Ask About Dental Sealants

Dental sealants are thin, plastic coatings painted onto the chewing surfaces of the back teeth, or molars. The chewing surfaces of back teeth have small pits and grooves where food and bacteria can get stuck and toothbrush bristles may have trouble reaching them. Sealants cover these surfaces and form a barrier that protects teeth and prevents food and bacteria from getting trapped there.

Since most cavities in children and adolescents develop in the back teeth, or molars, it is best to get these teeth sealed as soon as they come in:

The first permanent molars, called “6-year molars,” come in between ages 5 and 7.
The second permanent molars, called “12-year molars,” come in between ages 11 and 14.

Diagnosis

A dentist can identify tooth decay during a regular dental check-up. Signs of tooth decay include white, brown, or black staining on the tooth. If tooth decay is more advanced, it may form a hole, or cavity. A dentist can also:

Check teeth for soft or sticky areas
Take an X-ray, which can show decay

Treatment and Management

Once a cavity forms, it must be repaired by a dentist. To repair a cavity, a dentist removes the decayed tooth tissue and then fills the space with a filling material. In more severe cases of tooth decay when infection reaches the inner pulp tissue, a root canal treatment, to remove the damaged tissues within the tooth, may be needed. This dental procedure cleans and seals the affected tooth, thereby preventing further infection and saving the natural tooth.

There are several types of filling materials:

Tooth-colored (composite) fillings: Increasingly used because many people prefer their more natural look, and composites continue to improve
Silver-colored (amalgam) fillings: A traditional cost-effective option

For badly broken-down teeth, dentists may use treatments called crowns (or caps), which can be made of gold or other metals, porcelain or ceramic, or stainless steel (usually used on baby teeth). Generally, dental fillings and crowns do not last a lifetime and may need to be replaced.

Talk to your dentist about which type of dental filling works best for your teeth.

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on tooth decay.

Find Affordable Dental Care

NIH does not provide dental care or financial assistance for care. We are a research facility. The following resources may help you find affordable dental care:

Some dental schools have clinics where students treat patients at a reduced cost under the supervision of qualified dentists. You can find a list of dental schools here.
Dental hygiene schools may offer supervised, low-cost care as part of training for dental hygienists. You can view a list of dental hygiene schools.
Call your county or state health department to find dental clinics near you that offer free or reduced-cost dental care. See a list of state oral health programs.
To find a community health center near you that offers dental services, visit this searchable database of health centers. Health centers are in most cities and many rural areas, and you pay what you can afford, based on your income.
United Way chapters may direct you to free or reduced-cost dental services in your community. Dial 211 to reach a local United Way chapter or visit the United Way website.
Medicaid and Children’s Health Insurance Program (CHIP) are state-run programs that provide medical benefits for children to eligible individuals and families; most states offer limited dental services for adults, while some provide comprehensive services. States are required to provide dental benefits for children covered by Medicaid and CHIP. Visit the Medicaid website and click on “Learn How to Apply for Coverage” or contact your state Medicaid program. To find children’s dental care programs in your state, visit Insure Kids Now.
Medicare is a federal health insurance program for people 65 and older and for people under 65 with specific disabilities. Medicare only covers dental services related to certain medical conditions or treatments. It does not cover dentures or most routine care like checkups, cleanings, or fillings. Visit Medicare Dental Services.

Community Support

Note: This resource list is for informational purposes only. It is not comprehensive, and an organization’s inclusion does not constitute an endorsement by NIH.

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.

In recent decades, significant progress has been made in reducing tooth decay in the United States, although not all people have benefited equally. NIH supports research to develop more effective approaches to prevent and treat tooth decay and understand their causes.

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies. 