A cavity between two teeth is called an interproximal cavity. Just like any other cavity, interproximal cavities form when enamel is worn away and bacteria sticks to the tooth and causes decay.

Chances are you’ll be unaware of the cavity until one of two things happens:

  1. The cavity penetrates the enamel and reaches the second layer of tissue, known as the dentin. This can result in tooth sensitivity to sweets and cold and discomfort when chewing.
  2. Your dentist or dental hygienist spots the cavity, typically through a bitewing X-ray.

Depending on the severity of the cavity, your dentist might recommend one of five procedures:

  1. Recalcification. If the cavity is caught early and only extends halfway or less into the enamel, it can typically be recalcified with fluoride gel.
  2. Filling. If the cavity extends more than halfway into the enamel, a filling can be used to restore the tooth to its normal shape and function. Typically, the tooth will be drilled to remove decay, and the drilled area will be filled by a material such as porcelain, gold, silver, resin, or amalgam.
  3. Root canal. If the cavity is severe, having gone undetected and untreated for a long period of time, a root canal treatment might be the best option for saving the tooth. Root canal includes the pulp being removed from the inside of the tooth. Then, after the inside of the tooth is cleaned, disinfected, and shaped, a filling seals off the space.
  4. Crown. A crown is a natural-looking cover for the tooth that protects it. They are made from a variety of materials including ceramics, composite resin, metal alloys, porcelain, or a combination. If the tooth has large filling and there is not much natural tooth remaining, a crown may be used to cover the filling and support the tooth. Crowns are commonly added following a root canal.
  5. Extraction. If there are no other options and there is a possibility that infection may move from the tooth to the jawbone, an extraction is the last resort. The gap left by the extracted tooth can be filled with a bridge, a partial denture, or a dental implant.

Because your toothbrush doesn’t effectively clean the bacteria and plaque between your teeth, interproximal cavities can be difficult to prevent with brushing alone. Using dental floss between your teeth once a day will go a long way toward keeping the crevices and cracks between your teeth clean and cavity-free.

Your dentist might also recommend that you reduce your intake of sugary food and drinks and limit between-meal snacking to lower your chances of getting a cavity. They might also suggest cutting back or eliminating smoking and drinking alcohol.

The most effective dental hygiene for preventing cavities between your teeth is brushing twice every day with a toothpaste containing fluoride, flossing — or using another type of between-teeth (interdental) cleaner — once a day, and having regular examinations by your dentist.