# To prevent sensitivity caused by acid etching and to protect pulp in deep cavities, which of the following should be used?

# To prevent sensitivity caused by acid etching and to protect pulp in deep cavities, which of the following should be used?
A. Calcium hydroxide liner
B. ZnO liner
C. Light cure GIC liner
D. Lining with varnish

The correct answer is A. calcium hydroxide liner

Deep caries excavation close to the pulp, which may result in either an undetected pulpal exposure or a visible pulpal exposure, should be covered with a calcium hydroxide liner that can stimulate formation of dentin bridges (reparative dentin) over the exposure.

For amalgam restorations, deep excavations not encroaching on the pulp should be covered with a glass-ionomer material that will contribute to thermal protection and provide mechanical protection from amalgam condensation forces at thicknesses of I to 1.5 mm or greater.