After a chronic periapical abscess forms, how many WEEKS until a radiolucency becomes visible on a periapical radiograph?

Correct answer: C. 3 weeks

• A. Incorrect. Five weeks exceeds the minimum threshold cited in most references.
• B. Incorrect. One week is insufficient time for periapical bone loss to reach the threshold visible on standard 2D radiograph.
• C. Correct. It takes approximately 30–60% of the mineral content of bone to be lost before a change is visible on a standard periapical radiograph. This typically requires a MINIMUM OF 3 WEEKS for an acute lesion to show a detectable radiolucency. In clinical practice, periapical changes may not be radiographically apparent for several weeks after the inflammatory process begins.
• D. Incorrect. Four weeks is also cited in some sources — but the minimum threshold is typically around 3 weeks.