Teeth Straightening
Teeth Whitening
Updated on October 30, 2023
4 min read

What Do Cavities Look Like?

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Cavities are holes in teeth caused by tooth decay. They result from the breakdown of tooth enamel.

Tooth decay is a gradual process. Certain oral bacteria produce acids, which eat away at your enamel faster than your saliva can replenish it. Eventually, your enamel develops a permanent hole.

Dentists usually treat cavities by removing the infected portion of the tooth and then filling them in with a replacement material like composite resin. However, a crown, root canal, or extraction may be necessary if the decay covers a large area or has reached the pulp, or heart, of the tooth.

What Do Cavities Look Like?

A cavity may appear as a black, brown, or gray area on a tooth surface. Its appearance can vary from a tiny, dark spot to a large hole in the tooth.

Saliva or food may obscure a cavity from your view. Over time, however, a cavity may change color as the decay spreads deeper or wider.

In the very early stages, a developing cavity may appear white. This is generally before the enamel damage becomes severe.

Early Signs and Symptoms of Cavities

Besides the obvious appearance of a dark spot, patch, or hole on a tooth, you may also notice:

  • Pain or sensitivity when eating something hot or cold
  • Tooth sensitivity to cold air
  • Persistent toothache
  • Bad breath or a foul taste in your mouth

These symptoms can also be signs of other conditions, such as an infection or dentin hypersensitivity. Visit your dentist regularly to address potential oral health issues before they cause further problems.

What Causes Cavities? 

Your mouth is home to many bacteria. Some form plaque, a sticky substance that coats your teeth and gums.

These bacteria feed on the sugars and starches in your food. They use them to produce acids, which break down the calcium- and phosphate-based minerals in your enamel.

However, your saliva contains these minerals and naturally replenishes your enamel. Regular brushing and flossing also disrupt the formation of plaque.

Tooth decay occurs when enamel breakdown happens faster than your saliva can restore it. This can be caused by:

  • A diet high in sugars and starches — provides fuel for bacteria
  • Poor oral hygiene — allows plaque to continue to grow and spread
  • Dry mouth — less saliva means less mineral content to keep your enamel strong
  • Genetics — some people may be more susceptible to cavities due to differences in saliva pH and other factors 

When to See a Dentist for Treatment

See a dentist if you or your child has a visible cavity in one or more teeth. The earlier you seek treatment, the less extensive the treatment will have to be.

A fluoride gel or varnish may be enough to stop a cavity that has barely begun to form. But usually, a visible cavity will need a filling.

Your dentist will remove the damaged enamel from the cavity to place a filling material, such as composite resin or amalgam.

If a tooth has more extensive decay, your dentist may recommend a dental crown instead.

When Are Fillings Not Enough?

Decay that isn’t treated in time can eventually penetrate a tooth’s pulp. This is the soft tissue inside the tooth that contains blood vessels and nerve endings. The tooth may need a root canal or have to be extracted to prevent severe pain and infection.

It’s also possible for tooth decay to affect the roots of a tooth. Sometimes a filling is enough to treat root decay. But in other cases, the tooth may need more extensive treatment.

Can You Reverse a Cavity?

Yes, you can stop or reverse the early stages of tooth decay. However, once you notice a cavity, it’s often too late to repair it without a filling.

The things you can do to reverse a developing cavity are more or less the same as what you do to prevent them. Maintain a balanced diet, brush and floss regularly, and consider using a toothpaste with fluoride or hydroxyapatite to replenish your enamel.

Tips for Cavity Prevention

To avoid cavities:

  • Ensure good oral hygiene by brushing twice daily and flossing once daily
  • Use a toothpaste that contains fluoride or hydroxyapatite to remineralize enamel
  • Eat sugary or starchy foods in moderation
  • Include adequate levels of vitamins D and K2 in your diet (these are vital for dental health and remineralization)
  • Ask your dentist to apply a fluoride gel or varnish or dental sealant


Cavities are holes in the teeth caused by corrosive oral bacteria. These bacteria break down the minerals in tooth enamel, leading to visibly damaged areas.

If you have a cavity, it may appear black, brown, or gray. You may be able to tell that it’s a hole going into your tooth. Cavities that haven’t fully formed may appear as white spots.

You can prevent cavities and sometimes reverse them by maintaining good oral hygiene and a balanced diet. Also, see your dentist for regular checkups. If necessary, your dentist can treat cavities with fillings and other procedures.

Last updated on October 30, 2023
8 Sources Cited
Last updated on October 30, 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).
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