Internal root resorption is initiated by what process?

• A. Inflammatory mediators inducing osteoclastic transformation within the root canal system
• B. Bacterial invasion of dentin
• C. Pressure from occlusion
• D. Vitamin deficiency

Answer: (A)

Internal root resorption starts when the pulp becomes chronically inflamed and inflammatory mediators within the root canal stimulate odontoclasts (osteoclast-like cells) to differentiate and resorb dentin from inside the canal. This intr canal clastic activity is what drives the resorption, distinct from external processes or systemic factors. Bacterial invasion of dentin can accompany pulpal inflammation but does not initiate internal resorption itself; occlusal pressure or vitamin deficiencies do not trigger the internal clastic transformation occurring within the canal.