Hydrocal LC is a unique light-cured, radiopaque, dentinadhering liner and base material containing calcium hydroxide and calcium hydroxyapatite in a urethane dimethacrylate (UDMA) base.It is a highly filled resin (for a liner) with minimal shrinkage and water absorption. Hydrocal LC has a higher viscosity than conventional liners, eliminating the need for a ball-type applicator. Its superior strength and water insolubility make Hydrocal LC the material of choice under composite, amalgams, gold, and etc