[Etiology and pathogenesis of internal root resorption]

Internal root resorption is a pathologic phenomenon with a characterization of the intraradicular dentin destruction due to the abnormal activities of odontoclasts. With its insidious pathology, internal root resorption can progress to a great extent before its clinical detection. The etiology and natural history of internal root resorption are uncertain and the associated key molecular pathogenesis have not been understood completely. The resorption is usually initiated by a stimulus with the loss of the protective predentin and progressed by the continuous stimuli of pulp infection. Various factors including trauma, chronic inflammation of the pulp, pulpotomy and tooth transplantation have been proposed for the occurrence of internal root resorption. The present paper reviews the etiology and pathogenesis of internal root resorption and provides guidance for the early intervention in the clinical practice.