What liner is preferred when less than 1mm of tooth structure remains over the pulp?

When less than 1mm of tooth structure remains over the pulp, the preferred liner is Calcium Hydroxide. This is due to its unique properties that are particularly beneficial in situations where minimal dentin is present. Calcium Hydroxide has a high pH, which promotes the formation of secondary dentin and provides a therapeutic effect, helping to protect the pulp from thermal, chemical, and bacterial insults.

Additionally, Calcium Hydroxide stimulates reparative dentin formation, making it an ideal choice for deep cavities where the risk of pulp exposure is heightened. It also has antimicrobial properties, reducing the risk of infection. In contrast, other liners like Glass Ionomer or Zinc Oxide Eugenol may not offer the same level of pulp protection or promote reparative processes as effectively when there is such limited dentin over the pulp. Polycarboxylate is primarily used for its adhesive properties but lacks the specific benefits for pulp protection provided by Calcium Hydroxide.