Root Resorption: A Clinical and Biological Perspective

Root resorption is a pathological process characterized by the loss of dental hard tissues, including dentin and cementum, due to the activity of clastic cells such as odontoclasts and osteoclasts. In permanent teeth, it is classified as internal root resorption (IRR), which originates within the pulp space, and external root resorption (ERR), which begins on the root surface. Common etiological factors include dental trauma, pulpal and periodontal infections, orthodontic treatment, intracoronal bleaching, impacted teeth, and idiopathic causes.The pathogenesis involves damage to protective structures such as the periodontal ligament, cementum, or predentin, exposing mineralized tissues to clastic cell activity. Cytokines, prostaglandins, and the RANK/RANKL signaling pathway play key roles in the resorptive process. External inflammatory resorption is often associated with infected root canals, whereas replacement resorption results in ankylosis and substitution of root structure by bone.Diagnosis is challenging because many lesions are asymptomatic. Cone Beam Computed Tomography (CBCT) has significantly improved the detection and assessment of resorptive defects.