Resorption refers to the loss of tooth (mostly root) structure as a result of a variety of influences. The most common types of resorption are:
- Inflammatory root resorption at the end of the root.
- External Cervical Invasive Resorption that begins at or below where the enamel of the tooth meets the root. Although we don’t know what causes this process to begin, it is more frequently associated with patients who have had internal bleaching to whiten teeth with a material called Superoxol. It is also more common in those persons who have had extensive orthodontics as an adult. The third associated is recent dental trauma. ECIR is classified into 4 stages of progression. Classes 1 and 2 are smaller and more successfully treated, but difficult to diagnose as this process has no symptoms. Classes 3 and 4 are frequently not treatable due to the extensive destruction of tooth structure that has already occurred.
- Internal Resorption looks like a growing balloon in the middle of the root canal. The dentinoclastic cells continue to remove root structure until either removed by calcium hydroxide paste during two stage root canal treatment, or are inactivated when the pulp tissue becomes necrotic (dies).
- Replacement Resorption occurs as a result of dental trauma. There are often no signs or symptoms. After irreversible damage to the periodontal ligament (PDL), the bone cells grow into spaces of the root. Untreated, this may result in the complete loss of the root and the visible tooth. (One reason why it is essential to see an endodontist after experiencing dental trauma for an evaluation)