Calcium hydroxide liner is placed over exposed dentin in deep preparations to promote dentinal bridge formation.

Calcium hydroxide liner is placed over exposed dentin in deep preparations to promote dentinal bridge formation.

• A. Glass ionomer liner
• B. Zinc oxide eugenol liner
• C. Calcium hydroxide liner
• D. Resin liner

Answer: (C)

When dentin is exposed in deep cavities, the goal is to protect the pulp and stimulate natural dentin repair. Calcium hydroxide is bioactive and releases ions that stimulate pulp cells to form reparative (dentinal) tissue, leading to a dentinal bridge at the exposure site. This bridge provides a protective barrier and helps seal against microleakage under the restoration, which is why it’s the preferred liner in deep preparations. Other liners offer different benefits but don’t reliably promote dentinal bridge formation. Glass ionomer liners bond to dentin and release fluoride, providing good sealing and protection, but they don’t induce dentin bridge formation as effectively. Zinc oxide eugenol liners can soothe the pulp but may be irritating to dentin formation and can interfere with resin bonding. Resin liners seal well but lack the bioactivity needed to stimulate reparative dentin in exposed dentin scenarios.

When dentin is exposed in deep cavities, the goal is to protect the pulp and stimulate natural dentin repair. Calcium hydroxide is bioactive and releases ions that stimulate pulp cells to form reparative (dentinal) tissue, leading to a dentinal bridge at the exposure site. This bridge provides a protective barrier and helps seal against microleakage under the restoration, which is why it’s the preferred liner in deep preparations.

Other liners offer different benefits but don’t reliably promote dentinal bridge formation. Glass ionomer liners bond to dentin and release fluoride, providing good sealing and protection, but they don’t induce dentin bridge formation as effectively. Zinc oxide eugenol liners can soothe the pulp but may be irritating to dentin formation and can interfere with resin bonding. Resin liners seal well but lack the bioactivity needed to stimulate reparative dentin in exposed dentin scenarios.