Curing potential and color stability of different resin-based luting materials

Purpose. To determine the curing potential and color stability of resin-based luting materials for aesthetic restorations. Material and Methods. Four resin-based luting agents were tested: traditional dual-activated resin cement (RelyX ARC, ARC), amine-free dual-activated resin cement (RelyX Ultimate, ULT), light-activated resin cement (RelyX Veneer, VEN), and pre-heated restorative resin composite (Filtek Supreme, PHC). Degree of C=C conversion was determined by infrared spectroscopy (n = 3) with direct light exposure or with interposition of 1.5-mm-thick ceramic (e.max Press HT) between the luting material and light. The curing potential considered the ratio between these two scenarios. Color difference (n = 6) was determined by CIELAB (Delta E-ab) and CIEDE2000 (Delta E-00) methods, by spectrophotometer measurements made 24h after photoactivation and 90 days after storage in water. Data was submitted to ANOVA and Tukey's test (alpha = 0.05). Results. The luting agents affected both conversion and color stability. With ceramic, ARC produced the highest conversion among the tested groups (75 +/- 1%) and the pre-heated composite (PHC) the lowest one (51 +/- 3%), but the curing potential was similar for all materials. ULT produced lower Delta E-ab than ARC. PHC presented the lowest color difference when considered both CIELAB and CIE2000 methods (Delta E-ab 2.1 +/- 0.4; Delta E-00 1.6 +/- 0.2). Significance. All luting strategies presented high curing potential. Amine-free dual-activated material was able to reduce color difference than that formulated with the amine component. Pre-heated composite produced the least color variation after storage. (C) 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.