Cavities Between Teeth: What You Need to Know

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This article contains everything you need to know about cavities between teeth, what causes them, how to know if you have one, and what to do if you do.

Everybody who has teeth can get cavities. Yes, it’s that common. As a matter of fact, it is nearly impossible to reach adulthood without getting at least one cavity. The National Institute of Dental and Craniofacial Research (NIDCR) in the United States even said more than 92% of American adults have had cavities.

But while most cavities form on the outer layer (enamel) of the tooth, and usually around found the gum line and on the biting surface of the teeth, did you know that it can also form in between teeth? Cavities between teeth are called interproximal cavities, and they can be more distressing than your regular cavity.

What causes a cavity?

Your mouth is in a constant fight against various elements to remain cavity-free. However, when the bacteria that are naturally present inside your mouth come in contact with carbohydrate-rich and sugary foods and beverages, they can form acid. Combined with saliva, plaque and bacteria easily cling to the surfaces of the teeth. The acid demineralizes the enamel of the tooth, which leads to tiny holes and white spots that signals the deterioration of the tooth.

The demineralization process can lead to irreversible damage of the tooth, which then leads to the formation of cavities. Over time, cavities will further damage the enamel and expose the softer inner layer of tissue called dentin.

And since the damage is irreversible, cavities are permanent, which means you will need your dentist to repair it with fillings to save the tooth.

Cavities between teeth

An interproximal cavity is a form of tooth decay that hides between your teeth. They essentially have the same origin and physiology as regular cavities. However, they are quite harder to find. You can inspect your teeth in front of the mirror all day and they may seem to be in good shape, but unless you have x ray vision, you may never spot these cavities. These cavities lurk in between the crevices of two teeth. Fortunately, there are tell-tale signs of their existence.

Here are some signs and symptoms that suggest you have cavities between teeth.

Tooth sensitivity

Sensitivity to hot or cold beverages is one of the tell-tale signs of cavities between teeth. While it’s completely normal to experience tooth sensitivity from time to time, consistent sensitivity is different. This happens due to the wearing away of the tooth enamel, exposing the dentin, the soft inner layer tissue of the teeth. This sensitivity is characterized by tingeing or lingering pain.


Whether it’s mild or severe, toothaches are never considered normal. This is usually caused by an irritated or erupted tooth. While usually random, it can also happen when your teeth come in contact with a beverage or food that the cavities don’t like, or when you bite down on your food.

The pain can radiate all the way to the jaw and ear and can lead to headaches.

Teeth discoloration

Teeth should be off-white in color (or white if you had cosmetic dental whitening). Any discoloration such as the appearance of brown, black, or purple, is an easy sign of a cavity.

Bad breath

As bacteria consume trapped food between your teeth, they produce waste, and this is what causes bad breath.


When you see abscesses and pus around the gum line that means the cavity has gone so bad that it irritated the gums. This is a serious problem and must be checked with your dentist ASAP.

What to do if you have cavities between teeth?

First off, the right question should be: “what your dentist would do to fix your teeth?”

Depending on the severity, size, and location of the cavity, the damage may not be easy to see. This is why a dentist will require an x-ray to see every dental issue you have in your mouth. The treatment plan includes:

  • Recalfication – If the cavity is detected early (halfway or less into the enamel), it can be fixed by recalcification. Your dentist will use a recalcified fluoride gel to fill those tiny holes and cracks on the enamel of the tooth.
  • Filling – For cavities that have extended halfway through the enamel, the tooth will need filling to restore its normal shape and function. This includes drilling and removal of the decayed enamel and filling the area with amalgam, resin, and porcelain.
  • Root canal – In severe cases, the tooth may need a root canal – a dental procedure that involves the removal of the soft center of the tooth and its pulp (connective tissues, nerve, and blood vessels) to prevent infection and save the tooth.
  • Crown – This covers and protects the repaired spot of the tooth. This can be made by ceramics, porcelain, composite resin, metal alloys, or combinations of these materials.

Preventing cavities between teeth

As said earlier, cavities between teeth are similar in origin and physiology to cavities on other surfaces of the teeth. However, the treatment approach is quite different – to access the spots that need fillings, the dentist will have to take out more tooth structures.

As with anything, prevention is always better than cure. Thus, avoiding cavities is always better than treating cavities. This is where the importance of good oral hygiene gets into the picture. This means thorough brushing every after a meal using toothpaste with fluoride, flossing, and mouth wash.

To prevent cavities, make sure you clean the tight spaces between your teeth. Floss every day, or use an interdental cleaner. Food debris usually gets trapped in these tiny spaces, which becomes breeding grounds for the bacteria to flourish. A Diet low in sweets and drinking fluoridated water can also help to prevent cavities.


Brushing at least twice a day can go a long way in preventing cavities. Also, since most toothbrushes cannot reach the tight and tiny spaces between your teeth, it is always best to floss and remove all trapped food debris in crevices and cracks between your teeth.

More importantly, visit your dentist twice or at least once a year so he or she can spot any potential problems before they arise and become serious. Again, prevention is always better than cure!

Dr Febin Mary George - Editor

With more than 10 years as a dental surgeon, Dr Febin Mary George is passionate about educating consumers around the world to help look after their teeth.

She completed her Bachelor of Surgery at the Century Institute of Dental Science and Research Centre in 2010.

Alongside editing the International Journal of Dental Clinics she has also written for major publications including Thrive Global.