The endodontic radiographic film should extend beyond the apex by how many millimeters?

• A. 2-3 mm
• B. 4-5 mm
• C. 6-7 mm
• D. 8-9 mm

Answer: (B)

Capturing the apical region clearly is essential for endodontic assessment. Extending the film a small distance beyond the apex ensures the apex and surrounding periapical tissues are visible, which helps verify working length and detect any pathology or overextension of filling material.

The typical and most appropriate extension is about 2–3 millimeters beyond the apex. This provides enough of the periapical area to assess the tooth’s length accurately without exposing the patient to unnecessary additional radiation or including excessive anatomy beyond what’s needed for endodontic evaluation. Extending beyond a couple of millimeters offers little added diagnostic value for length determination and can increase exposure and image distortion risk.