Why is dual-cure composite used when building up the access opening after endodontic treatment?

Correct answer: B. Depth of cure — it cures in areas where the curing light cannot reach

• A. Incorrect. While dual-cure composites have good physical properties, the specific clinical reason is the curing depth limitation.
• B. Correct. In endodontic access restorations, the composite must fill the DEPTH of the access cavity, which may extend well beyond the 2 mm penetration depth of a curing light. DUAL-CURE composites chemically self-cure in areas unreachable by light, ensuring complete polymerization throughout the depth of the restoration — especially important in the pulp chamber and canal orifice area.
• C. Incorrect. Setting time efficiency is not the primary reason; the depth of cure is the critical factor.
• D. Incorrect. Esthetics is not the primary reason for using dual-cure composite in this context.