What is the purpose of smear layer removal before root canal obturation?

• A. To reduce postoperative sensitivity
• B. To enhance sealer penetration and improve the seal by removing debris and smear layer that can inhibit bonding
• C. To improve color stability
• D. To help seating of final restoration

Answer: (B)

The main idea is that the smear layer formed on canal walls during instrumentation can block bonding and impede sealer penetration. This debris layer covers the dentin and occludes dentinal tubules, so a sealer can’t adequately contact or infiltrate the walls. Removing the smear layer clears the canal surface, allowing the adhesive sealer to flow into and bond with the dentin, which improves the seal and reduces pathways for leakage. While other outcomes like restoration seating or color effects aren’t the primary goal, the key benefit here is enabling better sealer penetration and a stronger, more reliable seal at obturation.