Root resorption.

Several types of resorption affect teeth: internal, external, invasive, pressure, and idiopathic resorption. Diagnosis depends on an accurate medical and dental history, and radiographic and clinical examination. Because trauma appears to be a major factor associated with resorption, questions regarding past traumatic events may provide good leads to a likely cause. Treatment is determined based on a correct diagnosis. Root canal therapy is very beneficial in cases of internal resorption and external, inflammatory resorption. In cases of invasive resorption, it may or may not be necessary, whereas in replacement and pressure resorption, root canal therapy is not indicated at all (unless unrelated pulpal conditions necessitate endodontic intervention). Prevention of resorption includes appropriate treatment of traumatically injured teeth with frequent evaluation visits during the first year following an injury. Early detection of pressure-producing agents such as cysts, tumors, and impacted teeth can allow timely treatment to minimize the resorptive destruction.