Effect of energy density and delay time on the degree of conversion and Knoop microhardness of a dual resin cement.

Aim: In the present study, we evaluated the influence of the photo-curing delay time and energy density on the degree of conversion and the Knoop microhardness of a resin cement.

Methods: Seventy-eight samples were assigned to 13 groups (n = 6), one of which received no light curing (control). The samples were made of a dual-cured resin cement (RelyX ARC) with the aid of a Teflon matrix, submitted to one of the following energy densities (J/cm²): 7, 14, 20, and 28.