What are the most effective liners for pulp capping?

• A. Zinc oxide eugenol
• B. Glass ionomer cement
• C. Zinc phosphate cement
• D. Resin-containing Ca(OH)2

Answer: (D)

For pulp capping, the liner needs to protect the pulp, be biocompatible, and actively promote repair. Calcium hydroxide provides a highly alkaline environment that is antibacterial and stimulates dentin bridge formation, which is essential for healing a exposed or nearly exposed pulp. When resin is added to calcium hydroxide, the material forms a stronger bond to dentin and seals better at the interface, reducing microleakage and solubility. This combination combines the biological effect of calcium hydroxide with improved sealing and durability, making it more reliable for direct pulp exposure than other liners.

Zinc oxide eugenol, while soothing, does not consistently induce dentin bridge formation and can interfere with bonding to restorative materials. Zinc phosphate cement is acidic and not ideal for direct pulp exposure, potentially irritating the pulp. Glass ionomer cement is useful for sealing and fluoride release but does not match the dentin-bridge stimulating capability of resin-containing calcium hydroxide. Therefore, the resin-containing calcium hydroxide liner stands out as the most effective option for pulp capping.