Resorption is a spontaneous destructive process that results in decomposition of the tooth. The exact cause is unknown. The outcome varies significantly depending on the how early it is diagnosed, the type of resorption, and the extent of the resorption. CBCT imaging is essential for obtaining an accurate diagnosis and prognosis because it provides a 3D image whereas conventional radiographs do not.
Internal resorption is a destructive process that originates inside the root canal. Internal resorption can many times be successfully treated with conventional root canal therapy, especially if it is diagnosed early. A small or medium defect that does not perforate the external root surface has a favorable prognosis. A large defect that does not perforate the external root surface has a more questionable prognosis. A large defect that perforates the external root surface has an unfavorable prognosis.
External Invasive Cervical Resorption
External resorption is a destructive process that originates on the outer surface of the root. Some cases of external resorption can be successfully treated if it is diagnosed early. However, due to the sometimes rapid nature of progression, early diagnosis is less common. Two procedures are usually required to save the tooth: 1) conventional root canal therapy and 2) surgical repair of the external root surface.
A small defect located near the top of the root on a surface that is surgically accessible has a favorable prognosis. A medium defect located in the upper middle third of the root on a surface that is surgically accessible has a questionable prognosis. A large defect extending into the middle or lower third of the root or on a surface that is not surgically accessible has an unfavorable prognosis.