Cavities can sneak up on anyone, but when they form between your teeth, they’re especially tricky to spot. Known as interproximal cavities, these hidden areas of decay develop where two teeth touch—places that are difficult to see and even harder to clean properly. Left untreated, these cavities can spread quickly and lead to sensitivity, pain, or even infection. The good news? There are a few telltale signs that can help you catch the problem early. Here are 5 ways to know if you have a cavity between your teeth.
1. You Notice Sensitivity Between Your Teeth
One of the most common early signs of a cavity between teeth is sensitivity, especially when eating or drinking something hot, cold, or sweet. You may feel a sharp, temporary twinge when biting into ice cream or sipping hot coffee.
This happens because tooth decay gradually wears down your enamel—the hard outer layer that protects the inner nerves. When enamel becomes thin or compromised, temperature changes can reach the sensitive dentin layer underneath. If this sensitivity is new or focused between two teeth, it’s a good idea to have your dentist take a closer look.
2. Flossing Becomes Painful or Difficult
If flossing suddenly feels uncomfortable or your floss starts to catch, shred, or tear between specific teeth, that could be a red flag. Cavities can create rough edges or small holes in the enamel, making it harder for floss to glide smoothly.
You might also notice a twinge of pain or slight bleeding when flossing in that area. While this could also be a sign of early gum irritation, recurring pain between the same two teeth often points to an interproximal cavity.
3. You Have Persistent Bad Breath or a Bad Taste in Your Mouth
A cavity between your teeth can trap food particles and bacteria, leading to bad breath that brushing alone can’t fix. As bacteria feed on leftover debris, they produce acids and sulfur compounds that create unpleasant odors and tastes.
If you notice that your breath smells bad even after brushing, or there’s a sour taste in your mouth that won’t go away, it could be due to decay developing out of sight. A professional cleaning and dental exam can reveal if a cavity is the culprit.
4. You Feel Pain When Chewing
As a cavity grows deeper, it can reach the inner layers of your tooth where the nerves and blood vessels are located. This often results in pain or pressure when chewing, especially on one side of your mouth.
If biting down on certain foods causes discomfort—particularly sticky or crunchy ones—it’s a clear signal something isn’t right. Pain isolated between two teeth often indicates decay or a developing infection in that area.
5. Your Dentist Spots It on an X-ray
Sometimes, there are no obvious symptoms at all, which is why regular dental checkups are so important. Dentists use bitewing X-rays to detect cavities between teeth long before they cause pain or visible damage. Early detection means smaller, simpler fillings and less invasive treatment overall.
Cavities between teeth may be hidden, but they’re not invisible. Paying attention to signs like sensitivity, flossing discomfort, and bad breath can help you catch decay early. The best prevention, however, is maintaining a consistent routine of brushing, flossing, and seeing your dentist twice a year. Early intervention not only saves your teeth—it saves you from more extensive dental work down the road.
About the Author
Dr. Nicholas Baioni earned his dental doctorate from the University of Tennessee Health Science Center. After graduation, he worked for a year at a community health clinic, where he performed a variety of procedures for the underserved population. After that, he ventured into private practice. Today, Dr. Baioni stays current in the dental field through memberships in the American Dental Association and the Arkansas Dental Association. If you have cavities that need attention, schedule an appointment online or call (479) 370-2239.