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Tooth Resorption: Learn About Types, Causes, Symptoms and Treatment


You visit your dentist for a routine examination who finds a hole in one of your upper front teeth, just near the gum line and diagnoses it as a case of tooth resorption. Frightened, you start thinking about the fate of your tooth: Will you need a tooth extraction? Will this problem spread to other teeth? Is it even possible to treat it? Before we dig in further, here are some important points to remember about tooth and root resorption:

  • People with resorption usually feel no pain and are asymptomatic.
  • Resorption can be classified as internal or external, the latter being more common.
  • External resorption can be misdiagnosed so try to get opinions from multiple dentists.
  • Root canal therapy may help treat internal resorption, but if there is a large defect, the tooth may break off and fail to function.
  • The resorption is usually progressive, but even extensive cases can sometimes be reversed.
X-ray showing tooth resorption
X-ray of a resorbed tooth

For adults, root resorption is quite uncommon and a rather troublesome issue in which the body cells start eating away the structure of the teeth. If you are suffering from tooth resorption and wish to understand this issue, keep reading.

What is tooth resorption?

The term ‘resorption' normally refers to a process in which one part of your body draws in or absorbs another part. It may occur in different tissues located in various areas of the body. Tooth resorption, also known as root resorption, other than in babies, indicates the inflammation of various parts of the teeth followed by a complete loss of the affected parts.

According to the American Association of Endodontists, resorption can occur in both the inner material, dentin, and the outer material, cementum, of a tooth. Occasionally, the condition may also affect the interior pulp as well as the root of a tooth.

Tooth resorption often begins on the external surface of the tooth and may gradually move inwards. In addition to losing a part or parts of a tooth, you may also develop inflammation of the gums and other symptoms characteristic of this condition.

Types of tooth resorption

Depending on the exact location of tooth loss, resorption of the tooth is divided into two main classifications.

1. Internal tooth resorption

As indicated by the name, internal resorption affects the insides of the teeth. It is relatively uncommon compared to external resorption and mainly occurs in men. Internal resorption is also more prevalent in people who have recently undergone extensive oral surgery, for example, a tooth transplant.

The vast majority of patients suffering from internal resorption are unaware of this problem because it only targets the inside of a tooth so it's hard to see from the outside. Therefore, most cases of internal resorption are normally detected via X-rays performed as a part of a routine dental examination.

On an X-ray, an internally resorbing tooth will bear dark spots with a complete lack of internal tissue.

2. External tooth resorption

Also known as external root resorption, this problem is more common than internal resorption. From the root of the cementum, this problem can affect any external part of the tooth.

External resorption may appear on the outer surface of the tooth in the form of deep chips or holes. Resorption that extends to the roots of the tooth can be visualized in an X-ray report as a flattening of the root tips as well as a reduction in its length.

Tooth resorption can be devastating
Root resorption is never a physiologic process in adults

External resorption is further classified into several types:


External inflammatory resorption is normally caused by a prolonged trauma of the tooth ultimately giving rise to pathological resorption. Some of the most common causes of this type of resorption include the drying of the root surface after a trauma, previous surgery, injury to the periodontal ligament (PDL), pressure, or complete exposure of the dentine tubules.


This type of resorption normally is usually not too severe and is often diagnosed after an incidental finding on an x-ray. Also known as transient inflammatory resorption, it normally heals and only requires proper monitoring.

The common causes of this condition include a limited, localized injury to the root of the tooth or the surrounding area. Following injury, the affected area undergoes osteoclastic activity (the eating away of bone by cells) for 2 to 3 weeks before healing begins. If the problem is only limited to the cementum, it is possible to achieve complete healing. However, if the problem involves dentine, re-contouring will be needed.


External cervical resorption refers to a localized lesion in the cervical region of the tooth, just above where the root begins. The problem rarely extends to the pulp and is often caused by prolonged trauma leading to a horizontal and vertical growth of the lesion following periodontal treatment, trauma, or tooth whitening.


This type of root resorption occurs secondary to the stiffening or fusion of the root of the alveolar bone (the bone that keeps the teeth in place). It involves the resorption of the tooth tissue followed by a complete replacement with bone.

The reason why this happens is not well-understood. However, most orthodontic and dental experts believe that the process begins soon after the obliteration of the PDL and the union of the tooth and the bone. The damage to the PDL disrupts the release of the protective regulator that helps prevent root resorption. This encourages the osteoclasts (bone destroying cells) to completely resorb the tooth tissue and replace it with bone.

Diagnosis Mobility Percussion Color Vitality
External surface resorption Normal Normal Normal Normal
External inflammatory resorption Maybe increased - Normal Non-vital
Internal inflammatory resorption Normal Normal Possible pink discoloration Mixed response: positive in active lesions, absent in extensive lesions
External replacement resorption Absent Metallic sound Normal, may change depending upon nature of trauma Typically absent as sequelae of trauma
Internal replacement resorption Normal Normal Possible pink discoloration- Lion if lesion is coronally situated Mixed response

Learn more about tooth resorption in this video:

Tooth resorption causes

There are several factors that may lead to resorption of teeth. The most common cause of external resorption is an injury to the teeth and mouth that lead to swelling and loss of tissue and bone surrounding the affected teeth. Such injuries normally occur due to tooth grinding, using different orthodontic appliances like braces for a long time, or tooth bleaching.

In the case of internal resorption, the most common cause is trauma to the teeth following an untreated cavity.

Are there any complications?

Without proper treatment, root resorption may lead to a number of complications which include:

  • infection
  • discoloration and weakening of teeth
  • crooked teeth
  • chipping
  • cavity-like holes
  • gum recession
  • complete loss of teeth
  • toothache

Symptoms of tooth resorption

When it comes to root resorption, there is no clear set of symptoms. In most cases, the patient may not notice the problem for years. However, the symptoms soon begin to appear as the resorption worsens.

The most common symptoms of this problem include:

  • Pain beginning from the crown, root, or the inside of the tooth
  • Redness and swelling of the gums
  • Unequal spacing between the teeth
  • Brittle teeth
  • Development of holes in the teeth
  • Pink spots on the enamel

Diagnosing tooth resorption

The diagnosis of root resorption basically depends on the affected part of a tooth. In the case of internal resorption, the dental expert may notice the dark spots inside the teeth in an X-ray report. This is normally followed by a detailed dental history to confirm any past injuries or dental procedures that might have led to this problem.

A dental expert may also perform a physical inspection of the tooth. This normally includes taking X-rays and touching the affected teeth with cold and heat in order to understand the problem, its extent, and any other damage it might have caused.

External absorption can be seen with a naked eye; hence, it is easier to diagnose. The steps of diagnosis are similar to those of internal absorption.

Tooth resorption treatment

Treatment for root resorption normally varies according to the particulars of each case. If a dentist is able to spot the initial pink spots on the enamel of the tooth and remove the cells causing damage in time, you may not require any further dental care. However, if the tooth has developed cavities, root canal therapy might be the treatment of choice.

In the case of wide-spread damage, extraction of the affected teeth becomes necessary.

Tooth resorption can be treated
Various dental techniques can help restore your smile


Root resorption in adults is usually indicative of an underlying tooth injury that may cause long-lasting damage and even a complete loss of the teeth. It is possible to miss the symptoms of dental resorption until the disease has progressed to a more serious stage.

Routine dental examinations are recommended for the timely diagnosis and prompt treatment of the problem.


Does tooth resorption cause pain?

Yes, there is a possibility for all patients to develop resorption pain. However, it is relatively uncommon in replacement and inflammatory types of root resorption.

How common is root resorption?

Root resorption normally affects 5 to 10% of the general population who have never undergone any type of orthodontic treatment. It is considered among the most common causes of tooth loss in people across the world.

Can tooth resorption spread?

In the case of internal root resorption, the problem usually begins from the deeper layer of the tooth and works its way outwards. Just like a rotten piece of fruit in a bowl damages the healthy pieces placed near it, root resorption can also spread to surrounding gums and teeth and destroy them.

Can tooth resorption be reversed?

No, a reversal of tooth resorption is not possible in most cases. Therefore, all teeth with resorbed roots must never be subjected to treatment with an aim to reverse this problem.

Is tooth resorption an autoimmune disease?

Idiopathic root resorption is a type of root resorption that is autoimmune in nature. It commonly occurs in people suffering from scleroderma and is often diagnosed in dental X-rays reports. However, this condition is quite rare.

What is normal dental resorption?

While resorption in adults may cause long-term damage to a permanent tooth, it is a normal developmental process in baby teeth. The baby teeth of all children continue to resorb as they grow up. This process is important as it makes way for permanent teeth to replace the baby teeth.

However, it is important to differentiate between normal dental resorption and bottle rot, a condition in which the teeth of a child get coated with sugar due to over-consumption of sugary beverages.

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Dr. Junaid Tariq
Dr. Junaid Tariq
Dr. Junaid Tariq is a professional content creator and copywriter. The meticulous nature of his MBBS degree proved invaluable in sculpting his research skills and honing his writing efficiency. In addition to working as a content creator, Dr. Tariq continues to fulfill his duties as a medical doctor at a local hospital and has acquired hands-on experience in both acute and chronic patient care. From white papers to blogs, Dr. Tariq writes everything, simplifying complex scientific concepts into basic terms to create something easily accessible and readable for the majority.
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Dental press journal of orthodontics: Extreme root resorption associated with induced tooth movement: a protocol for clinical management. Consulted 19 February 2020. The medical journal, Armed Forces India: Salvaging a tooth with extensive invasive cervical resorption. Consulted 19 February 2020. The medical journal, Armed Forces India: Internal resorption: an unusual form of tooth resorption. Consulted 19 February 2020. Dental press journal of orthodontics: External cervical resorption: diagnostic and treatment tips. Consulted 19 February 2020. American Association of Endodontists: Treatment Options for the Compromised Tooth: A Decision Guide. Consulted 4th March 2020.