What is a periapical granuloma?

• A. Proliferating chronic inflammatory tissue enclosed in a fibrous capsule, continuous with the PDL at the tooth apex, resulting from necrotic pulp.
• B. A fluid-filled cavity lined with epithelium.
• C. A localized pus collection at the tooth apex.
• D. An acute bacterial infection of the pulp.

Answer: (D)

A periapical granuloma is a chronic inflammatory lesion at the apex of a nonvital tooth created by granulation tissue that arises from irritation from a necrotic pulp and is continuous with the periodontal ligament. It represents long-standing inflammation, not an acute infection, and it is not a fluid-filled cavity or a pus pocket. So the description that best fits is a proliferating chronic inflammatory tissue at the tooth apex connected to the PDL due to pulpal necrosis. This differs from a cyst, which would be an epithelial-lined cavity, and from an abscess, which is a localized collection of pus.