Among irrigants, which removes the smear layer during the chemomechanical preparation sequence?

Among irrigants, which removes the smear layer during the chemomechanical preparation sequence?

• A. Saline
• B. Hydrogen peroxide
• C. EDTA
• D. Sodium hypochlorite

Answer: (C)

Removing the smear layer during chemomechanical preparation relies on agents that target the inorganic component of dentin. The smear layer is a thin film created during instrumentation that covers canal walls and blocks dentinal tubules. EDTA is a calcium-chelating agent; it binds calcium in hydroxyapatite and dissolves the inorganic portion of the smear layer, effectively removing it and exposing the tubules. This allows better penetration of sealers and improves disinfection. Saline is an inert rinse, hydrogen peroxide mainly aids in oxidizing organic tissue, and sodium hypochlorite dissolves organic matter but does not remove the inorganic smear layer. Thus EDTA best accomplishes smear layer removal.

Removing the smear layer during chemomechanical preparation relies on agents that target the inorganic component of dentin. The smear layer is a thin film created during instrumentation that covers canal walls and blocks dentinal tubules. EDTA is a calcium-chelating agent; it binds calcium in hydroxyapatite and dissolves the inorganic portion of the smear layer, effectively removing it and exposing the tubules. This allows better penetration of sealers and improves disinfection. Saline is an inert rinse, hydrogen peroxide mainly aids in oxidizing organic tissue, and sodium hypochlorite dissolves organic matter but does not remove the inorganic smear layer. Thus EDTA best accomplishes smear layer removal.