The curing potential of light-activated composite resin luting agents.

This study determined the effect of different light exposure times on the polymerization of three composite resins used as cements (Heliosit, Visio-Fil, and Dual) through various thicknesses and shades of two preprocessed composite resins (Isosit and Visio-Gem). The Knoop hardness of the surface of the luting resin was measured after polymerization and selected samples were remeasured at 24 hours to evaluate continued cure. Results indicated that polymerization of light-activated composite resin luting agents cannot predictably be accomplished through a restoration exceeding 2 mm in thickness using a light exposure of 90 seconds or less. The combined chemical and light-activated cure of Dual cement recorded the highest percentage of acceptable hardness values.