**Question:** Internal resorption is due to

A. deficiency of calcified tissue
B. abnormal bone remodeling
C. increased root resorption
D. inflammation-induced resorption

**Core Concept:** Internal resorption is a pathological process characterized by the dissolution of dental pulp tissue within the root of a tooth. This process leads to the formation of a root canal and can cause pain, swelling, and mobility of the affected tooth.

**Why the Correct Answer is Right:** Internal resorption occurs due to abnormal bone remodeling, specifically due to the activation of osteoclasts, which are specialized cells responsible for breaking down bone tissue. In the context of internal resorption, an imbalance in the balance between osteoclast and osteoblast activity leads to the dissolution of dental pulp tissue in the root canal. This process is not related to deficiency of calcified tissue, increased root resorption, or inflammation-induced resorption.

**Why Each Wrong Option is Incorrect:**

A. Deficiency of calcified tissue: Internal resorption is not caused by a deficiency of calcified tissue but rather an imbalance in bone remodeling.

B. Abnormal bone remodeling: While internal resorption involves abnormal bone remodeling, the correct answer is focusing on the abnormal activity of osteoclasts, not the overall bone remodeling process.

C. Increased root resorption: Root resorption refers to the loss of tooth structure, including the root, due to various causes. Internal resorption specifically focuses on the dissolution of dental pulp tissue, not root resorption.

D. Inflammation-induced resorption: While inflammation can contribute to internal resorption, the correct answer emphasizes the role of osteoclasts in breaking down the dental pulp tissue rather than inflammation as the primary cause.

**Clinical Pearl:** Internal resorption is a complex process involving the interaction between osteoclasts, dental pulp cells, and inflammatory mediators. Understanding this process is essential for diagnosing and treating internal resorption effectively, as it guides treatment decisions like root canal therapy, pulpectomy, or extraction, depending on the extent and progression of the resorption.