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Tooth Decay (Dental Caries)

The decay of a tooth, in which it becomes softened, discolored, and/or porous.

PubMed Health Glossary
(Source: NIH - National Cancer Institute)

About Tooth Decay

Tooth decay (also called cavities or caries) is caused by bacteria, sweet foods and drinks, and a lack of oral hygiene. It can harm your teeth and cause a lot of pain, and may even result in loss of teeth.

Today tooth decay is much less common than it was just a few decades ago. That is mostly due to better oral hygiene and more people using fluoride toothpaste, which goes to show that there are a number of things you can do to improve the health of your teeth and prevent cavities.


White or brown spots on your teeth are the first sign of tooth decay. If it gets worse, holes develop on the surface of the teeth (cavities), and if the deeper layers of the teeth are affected, tooth decay can also harm the nerves in the teeth and the root. Then the teeth become sensitive and painful — especially when eating anything cold or sweet. Tooth decay can cause so much damage to the teeth that it may no longer be possible to save them... Read more about Tooth Decay

What works? Research summarized

Evidence reviews

Prevention of Dental Caries in Children Younger Than 5 Years Old: Systematic Review to Update the U.S. Preventive Services Task Force Recommendation [Internet]

A 2004 U.S. Preventive Services Task Force (USPSTF) review recommended that primary care clinicians prescribe oral fluoride supplementation to preschool children over the age of 6 months whose primary water source is deficient in fluoride but found insufficient evidence to recommend for or against risk assessment of preschool children by primary care clinicians for the prevention of dental caries.

Ozone therapy for the treatment of dental caries

There is no evidence that ozone therapy can reverse or stop tooth decay.

Fluoridated milk for preventing dental caries

Insufficient evidence exists to show the effectiveness of fluoridated milk in preventing tooth decay.

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Summaries for consumers

Preventing tooth decay in children and teenagers

Tooth decay, also known as dental cavities or caries, is the most common dental problem amongst children. It can cause painful holes (cavities) in your teeth. The tooth material surrounding the cavity usually needs to be drilled out and then filled to keep the tooth decay from getting worse. But careful prevention can help to make treatment unnecessary.Regularly brushing your teeth and strengthening them by using fluoride are the most effective ways of preventing tooth decay. Sticking to a healthy diet and not eating too much candy or sweets is also important. And dental check-ups can also help detect and treat tooth decay early on.

Tooth decay: Overview

Protecting teeth from tooth decay and cavities is child’s play: A healthy diet, sugary foods and drinks in moderation, and good oral hygiene are the essentials. Here you can find information on the most important dental care products and when you might need fissure sealants on your back teeth.

Ozone therapy for the treatment of dental caries

There is no evidence that ozone therapy can reverse or stop tooth decay.

See all (58)

More about Tooth Decay

Photo of a child

Also called: Cavities, Dental cavities, Holes in the teeth

Other terms to know:
Dental Enamel

Keep up with systematic reviews on Tooth Decay:


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