How much periapical bone must be captured?

• A. ≥ 1 cm
• B. ≥ 2 mm
• C. ≤ 2 mm
• D. None required

Answer: (B)

In periapical imaging, you need a small amount of bone visible beyond the tooth’s apex to reliably assess the surrounding structures. The standard minimum is at least 2 mm of periapical bone captured past the apex. This margin helps you clearly see the root tip and any early periapical changes, reducing the risk of missing pathology or misinterpreting the apex location. Options that call for more than this (like 1 cm) aren’t necessary, and those suggesting less than 2 mm or no bone at all wouldn’t provide a dependable view. Therefore, capturing ≥ 2 mm of periapical bone is the correct guideline.