What constitutes an adequate coronal and apical seal after obturation, and what radiographic signs indicate poor obturation?

• A. A patchy fill with many voids but still at working length.
• B. Radiographs showing obvious voids or radiolucencies at the apex indicate poor obturation.
• C. A dense fill that overextends beyond the apex.
• D. Only sealer visible radiographically.

Answer: (B)