Development of a low-color, color stable, dual cure dental resin

a b s t r a c t Dual-cure (DC) resins are mainly used as cements due to high initial color (generally yellow) and large color shift (E*) after polymerization as compared to light-cured resins. However, even as cements, this color shift is clinically unacceptable, especially when used to cement thin veneers. Objective. To develop a novel DC initiator system with both lower initial color (less yellow, i.e., whiter) and smaller E*. Methods. The effect of using an allyl thiourea (T)/cumene hydroperoxide (CH) self-cure (SC) initiator system in combination with a photo-co-initiator, p-octyloxy-phenyl-phenyl iodonium hexafluoroantimonate (OPPI), in a commercial DC resin cement (PermaFlo DC, Ultradent Products, Inc.) was investigated. Initial color and E* were assessed for 6 weeks in vitro under accelerated aging conditions (75 ◦ C water bath). Rockwell15T hardness was