When most people hear the word “cavity,” they think of a hole or opening in the surface of a tooth. But is it also possible to have a cavity that starts on the inside of a tooth?
The simple answer is that dental caries—commonly known as cavities—start on the outside of teeth. However, there are times when a tooth starts to decay from the inside out. While dental caries are caused by bacteria and acids in the mouth that erode tooth enamel, decay that starts on the inside of a tooth is usually caused by trauma or an injury to the tooth. This can cause the tooth to “die” or “rot” from the inside. While this type of dental issue is not technically a cavity, it does require the attention of a dentist.
Could It Be a Recurrent Cavity?
Before exploring the causes of a tooth dying from the inside, it’s important to note that some patients experience cavities that come back on the inside of a tooth after it has been restored with a filling or root canal. Recurrent cavities can be caused by poor dental hygiene, lack of fluoride (a chemical in toothpaste and dental rinses that helps harden tooth enamel), or the filling breaking down over time. Sometimes recurrent cavities start next to the filling on the inside of the tooth, making them difficult to detect.
Patients can help prevent recurrent cavities by practicing good oral hygiene, getting regular dental check ups, and avoiding very hard or sticky foods that can damage fillings.
When a Tooth Decays from the Inside Out
When decay or rot starts on the inside of a tooth that does not already have a filling, it is usually due to an injury or trauma to the tooth. Trauma to the teeth can occur in a variety of ways, including physical injury, accidents, or infection. For instance, sports-related injuries are a common cause of dental trauma.
Of course, some dental trauma is severe, causing teeth to be broken or even knocked out. Though not all dental injuries are this bad, a seemingly minor blow to a tooth can still cause damage to the tooth’s pulp. Located in the center of the tooth, the pulp is soft tissue that contains nerves and blood vessels. The pulp is what allows teeth to sense hot and cold, as well as pain. Trauma to a tooth can interrupt blood flow to the pulp. As a result, the tooth can decay or die from the inside out.
This process can cause sensitivity to hot and cold, as well as a painful toothache. Because these symptoms are similar to those of a cavity, the patient may wonder if they have a cavity inside a tooth when it starts to die. The patient may also notice that it looks darker than surrounding teeth. Because the blood supply to the tooth has been cut off, the tooth starts to break down and become discolored. Over time, it can darken from yellow to gray, brown, or even black.
Once the pulp dies, the tooth can still function normally, though it will no longer be able to feel hot or cold temperatures or pain. However, an injured tooth that is dead or dying has a high risk of infection if it is not treated.
When a patient’s tooth is sensitive, painful, and/or starts to discolor, it’s important to see a dentist. Though the dentist may not be able to stop the tooth from dying, they may recommend a root canal to prevent infection.
When to Consult a Dentist
Though decay that starts inside a tooth isn’t the same as a typical cavity, it’s important to have any tooth with signs of trauma or infection examined by a dentist. In fact, it’s a good idea to visit your dentist after any accident involving the teeth. Dentists have a number of advanced techniques they can use to save an injured tooth if they act quickly. Even if saving the tooth is not possible, the dentist can monitor and help prevent infection in a dying tooth.
Without a healthy blood supply, a tooth that is rotting from the inside out can become infected. An untreated infection can lead to an abscess. This is a pocket of pus that develops when bacteria from the infection invades the inner layer of the tooth and surrounding gums.
A dental abscess can be extremely painful. If left untreated, an abscess can lead to serious complications such as bone loss, loss of teeth, and facial disfigurement. Symptoms of a dental abscess include severe toothache, fever, facial swelling, a bad taste in the mouth, foul breath, or difficulty swallowing. The presence of a dental abscess means infection has settled into the tooth and gums, and it will not go away on its own.
Dentists typically start treatment by draining the abscess and prescribing antibiotics to clear the infection. Unlike other types of bacterial illnesses that can be cured with antibiotics alone, a tooth abscess must also be treated to physically remove the infection. The dentist will usually recommend a root canal or extraction. A root canal involves cleaning out the damaged or infected tissue (including the nerves and blood vessels) and sealing off the tooth from further decay. If a root canal is not possible, the tooth may need to be pulled out, which is called an extraction, to stop the infection.
It’s vitally important to have any abscess treated by a dentist as soon as possible. In addition to causing pain, if untreated, the infection can spread to other areas of the body and cause serious problems.
Think You Have Decay Inside a Tooth?
Whether you have experienced an injury to your teeth, are feeling pain, or are noticing tooth discoloration, it’s important to visit a dentist to see if your tooth is decaying on the inside. Dentists can often save injured teeth if the trauma is addressed quickly. Teeth that cannot be saved can be monitored and treated for infection before it gets serious.
Our online database has numerous dentists for routine oral care, as well as dentists who are skilled in managing dental trauma. Find one in your neighborhood now.