C

Light-cured resin-modified glass-ionomer (GIC) liners form an acid-resistant barrier over dentin, reducing the penetration of phosphoric acid during etching and sealing dentinal tubules; they also provide a biocompatible layer that protects the pulp in deep preparations. Clinical studies show lower post-operative sensitivity when a light-cured GIC liner (e.g., Vitrebond) is placed under composite restorations compared with no liner or other liners [Akpata & Sadiq, 2001, PMID 11806478], and histologic work demonstrates minimal pulpal irritation with these materials even in deep cavities [Gaintantzopoulou et al., 1994, PMID 9115678].