What is the effect of smear layer removal on obturation sealing?

• A. The smear layer enhances sealer penetration
• B. The smear layer has no impact on bonding
• C. The smear layer is removed to aid the cleaning of the canal walls
• D. Removing the smear layer before obturation improves seal by enabling better sealer penetration

Answer: (D)

Removing the smear layer exposes the tiny dentinal tubules that instrumentation tends to cover with debris. When you obturate, a sealer can then penetrate into those tubules and interact with the dentin, creating a stronger micromechanical bond and a tighter overall seal. This reduces voids and potential leakage pathways, leading to a more reliable, hermetic obturation. In short, taking the smear layer away before sealing lets the sealer enter and adapt better to the canal walls, improving the seal.