Root resorption is a form of pathology, in which tooth structure is progressively eaten away by an inflammatory process. There are basically 2 types of resorption, Internal and External. Internal resorption becomes arrested as soon as the pulp is removed, and so treatment depends on the extent of damage already created. If the damage is beyond repair, extraction is indicated, otherwise, root canal therapy is performed. External resorption is a more difficult process to treat, in that there is no definitive way to halt the process. Since this process does not originate in the pulp, but rather in the periodontal tissues, root canal therapy alone will not arrest the process. Sometimes the lesions caused by External Root Resorption can be surgically cleaned out and repaired with a special filling on the root surface, and in such cases, root canal therapy would almost always be necessary prior to the procedure. In such cases, extraction and implant placement is sometimes a better alternative.