Influence of ceramic translucency on curing efficacy of different light-curing units.

Purpose: The aim of the study was to examine the influence of dental ceramic translucency under different exposure conditions upon the polymerization rate of a dual-curing composite resin by measuring the depth of cure (DOC) and the Vickers microhardness (VHN).

Materials And Methods: Three hundred twenty ceramic specimens (160 Empress 2, Ivoclar Vivadent, color 300, and 160 ProCAD, Ivoclar Vivadent, 300, 114; diameter 4 mm, height 1 mm or 2 mm) were inserted into steel molds and overlayed using a composite resin (Variolink II, Ivoclar Vivadent) with and without a self-curing catalyst. Specimens were cured either in contact with or at a 5-mm distance from a conventional halogen curing light (Elipar TriLight, 3M ESPE, exposure duration 40 s, standard mode) and a light-emitting diode (LED: Bluephase 16i, Ivoclar-Vivadent, exposure duration 20 s, high-power mode).