Internal resorption is a process in which the tooth is eating itself away from the inside.  External Resorption is a similar process in which the tooth is eating itself away from the outside. 



The causes are not completely known, but there are several possible sources.

Internal Resorption causes:

External Resorption causes:


Often times there will not be any symptoms, but the process will be identified off of an X-ray or clinical examination.

The tooth may have some pain, aching, throbbing, may feel loose, or may not illicit any signs or symptoms known to the patient. 

As shown in the photo below, a normal pulp and one that has internal resorption going on is pretty obvious.  It is a different appearance than cavities or dental decay, but may be difficult to distinguish by the untrained eye.


Internal Resorption treatment:

Usually root canal therapy will need to be done in this situation.  Unlike conventional root canal treatment, often times the tooth will need to be medicated with calcium hydroxide or a similar medicament in order to help promote healing.

If there is a source of trauma, that should also be removed if possible. 

External Resorption treatment:

Although normally seen after orthodontic movement, if it is occurring during tooth movement, it is normally wise to prevent further movement or decrease the amount of force that is applied to the teeth at each appointment.

If there are any current periodontal conditions or infections, they are usually treated with regular dental cleanings, deeper cleanings called scaling and root planing, and may include localized antibiotic therapy.

If there are any nearby impacted teeth or tumors, obviously those should removed to allow the best chance for healing.

Reimplanting teeth that have been knocked out, or avulsed, is a very difficult and has a low success rate.  External resorption is a common result and may cause the loss of the tooth. 

If there is any known source of trauma, even possibly occlusal or biting forces, they may need to be alleviated in order to help give the best chance to stop the process.


Internal resorption:

If the process is identified early and a successful root canal is completed, the tooth may be maintained for many years.  As with most root canals, the tooth will also need to be restored properly, usually with a crown, and be monitored on a regular basis.  

If the process is not identified early, it is common for the tooth to become very fragile due to loss of tooth structure and often times will need to be extracted, especially if the tooth gets eaten through to the external surface of the tooth.

See case study here.

External resorption:

If the external resorption is around the root of the tooth, causing shortening of the root, often times there is not much that can be done aside from maintaining the tooth as long as possible, or removing it and opting for an implantbridge, or removable type tooth replacement. 

If the resorption is on the crown, it will usually need to be cleaned out and filled similar to a dental cavity.  The tricky part, is often times the process begins at or below the gum line, and is very difficult to identify, or get access to in order to treat.

When this is the case, often times gum surgery needs to be done in order to gain access to the resorptive process, and if the process has proceeded far enough, the tooth may need to be extracted.  It also may involve needing a root canal, if the process has progressed into the nerves of the tooth.

Because the treatment is potentially very involved, it is always best to consult your dentist to decide if it is worth it to treat, or to let it go and extract as needed in the future.


This is a good question sometimes.  If a tooth is not causing any problems, would you rather do a root canal, crown, and gum surgery, or just let it be and remove it if it ever causes problems?  All of that treatment may still end up with the tooth being extracted; and doing an implant or bridge may be more predictable.

On the other hand, if internal resorption or external resorption is identified early, it often is possible to treat without too much trouble and allow you to keep your tooth for many more years.

Read about Root Canals here. 

Return to home.

New! Comments

Have your say about what you just read! Leave me a comment in the box below.