The idea that your body could suddenly turn on itself and begin to reabsorb your bones sounds like something straight from a bad horror film. Usually, your body and its vigilant immune system is able to accurately identify invaders, but sometimes the signals get crossed. External resorption is a dental condition that happens during one of those times.
What is tooth resorption?
The body has two processes that are occurring all the time: deposition and resorption. These two processes are responsible for building bones and tissues (deposition) and breaking down removing waste (resorption). Sometimes this natural balance is disrupted in one direction or the other. Tooth resorption occurs when the body begins to dissolve and eat away directly at a tooth’s structure.
There are two main types of tooth resorption: internal and external. Internal resorption begins in the dental pulp of the tooth (or at the tooth’s roots). External resorption starts on the outside, either above or just below the gumline.
Tooth anatomy
Understanding a tooth’s anatomy can help you get a clearer picture of both internal and external root resorption. The outside of your tooth is covered in protective enamel. And, underneath that is a hard layer of dentin. This surrounds a dental chamber filled with living cells, tissues, and nerves. The tooth’s roots extend from the crown of the tooth (the visible part of the tooth) into the gumline. The roots are encased in connective tissue called cementum that attaches the roots to the jawbone.
Tooth resorption begins to erode the tooth from either the inside out (internal root resorption) or the outside in (external root resorption). In children, tooth resorption is a normal process that allows baby teeth to make way for adult teeth. For adults, there are no other teeth waiting to fill a gap left by tooth resorption. This can lead to dental conditions down the road.
External root resorption occurs most often in the upper middle teeth and the upper canines. In most cases, tooth resorption begins just where the crown of the tooth begins to dive into the gumline (the cervical region of the tooth).
What causes external resorption of a tooth?
External tooth resorption is the most common of the two types. It is challenging to pinpoint specific causes, but there are a few risk factors.
Trauma
Most dentists agree that trauma is a main culprit when it comes to external root resorption. The body seems to recognize damage from a blow to the mouth as an invader and begins to attack that area.
Fast-moving (or long-term) orthodontia
Orthodontic work does wonders to improve the bite and cosmetic appearance of your teeth, but it is important to monitor a tooth’s roots carefully.
Some root shortening is normal during routine orthodontia (and is usually not damaging), but for patients who have fast-moving orthodontia or braces for a long time, this can turn into external root resorption. Tooth resorption may not occur for a number of years after braces.
Bruxism
Teeth grinding and clenching causes many serious dental conditions, and this one is no different. The constant pressure and movement of bruxism can cause trauma to your tooth’s external structure as well as the root itself.
Do I have external root resorption?
External resorption is tricky to diagnose. Many patients who have the above external resorption causes never develop external resorption. Patients who have no risk factors can show external root resorption symptoms.
The best way to figure out your risk is to have regular dental cleanings and check-ups to keep track of your overall oral heath.
Common external root resorption symptoms
The most common external root resorption symptom is the development of a cavity-like lesion on the visible part of the tooth (or in the cervical region at the gumline). This lesion appears as a small pink spot on the tooth.
As tooth resorption progresses, the spot turns brown or grey, appearing even more like a cavity. Unlike a cavity, this lesion does not feel “sticky” when probed with a dental scaler. These two characteristics (the pink color and the non-stickiness) are the best way to differentiate external resorption from a cavity.
These lesions are not usually accompanied by pain or any other external root resorption symptoms. Unfortunately, once a lesion shows up as a dark spot on an X-ray, external resorption has already progressed.
What external root resorption treatments work?
The best external resorption treatments are those that take place in the earliest stages of the condition. In this case, an ounce of prevention really is worth a pound of cure. Twice-yearly visits to your dentist, along with once-yearly full-mouth dental X-rays, can catch the early signs of external resorption for the best chance of treatment success.
In the early stages, your dentist treats external resorption in much the same way as a cavity. Your dentist drills and cleans out the lesion. They will then use a tooth-colored composite resin to fill in the cavity. This alone may be enough to stop the process of resorption so that deposition can begin to build new bone or tooth material.
If the lesions have progressed and are making their way through the dentin and into the dental pulp, a root canal may be necessary. The damaged dentin and dental pulp will be removed in the same way as a cavity. Then, the dental chamber is filled in. While root canal therapy is more involved than a simple cavity filling, much of the natural tooth is preserved.
As external resorption gets more serious, so do the treatment options.
If your tooth turns completely grey and has no sensation, you may have a “bad” tooth that cannot be saved. In this case, the best option may be either a crown (if the tooth’s roots can be saved) or an extraction and dental implant if the tooth is too far gone to support a crown. With a highly-qualified dentist, both of these options can result in an attractive, long-lasting smile.
A twice-yearly visit to your Phoenix area dentist can help preserve your oral health. Give us a call today at AZ Dentist to learn more!