What is an abscess?

• A. Localized accumulation of pus.
• B. A cavity filled with fluid.
• C. Widening of the periodontal ligament.
• D. A chronic granulomatous lesion.

Answer: (A)

An abscess is a localized accumulation of pus caused by infection. Pus is a thick fluid rich in neutrophils, bacteria, and cellular debris that collects in a confined pocket within tissue. In dentistry, abscesses can form at the root tip (periapical) or in the surrounding soft tissues (dentoalveolar), and they typically present with localized swelling, tenderness, and sometimes fever or malaise.

This definition helps distinguish an abscess from other conditions. A cavity filled with fluid suggests a fluid-filled space like a cyst rather than pus. Widening of the periodontal ligament is a radiographic sign that points to periodontal or occlusal trauma but doesn’t describe a pus-filled pocket. A chronic granulomatous lesion refers to a granuloma, a different type of chronic inflammatory tissue with macrophages and giant cells, not an acute collection of pus. So the best description is a localized collection of pus.