AbstractStatement of problem.
The color of resin cements and computer-aided-design and computer-aided-manufacturing (CAD-CAM) restorations may change with aging.Purpose.
The purpose of this in vitro study was to analyze the influence of thermocycling on the color of CAD-CAM materials with underlying resin cement.Material and methods.
Seven different CAD-CAM materials, composite resins and glass-ceramics were cut into 0.7-mm and 1.2-mm thicknesses (n=10) and cemented with a dual-polymerizing resin cement, a light-polymerizing resin cement, and a preheated composite resin (N=420). Color values were measured by using spectrophotometry. Specimens were subjected to thermocycling (5°C and 55°C; 5000 cycles). The measured color difference (ΔE) data were analyzed by using descriptive statistics. Normality of data distribution was tested by using the Kolmogorov-Smirnov test. Three-way and 1-way ANOVA followed by the Scheffé post hoc test and unpaired 2-sample Student t test were computed to determine the significant differences among the tested parameters (α=.05).Results.
ΔE values were significantly influenced by the CAD-CAM material (ηp2=0.85, P<.001) and the resin composite cement (ηP2=0.03, P=.003) but were not influenced by thickness (P=.179). Significant interactions were present among thickness, cement, and CAD-CAM materials (P<.001). Vita Suprinity and GC Cerasmart showed significantly the lowest ΔE values (P<.001). The highest ΔE values were observed for IPS Empress CAD. The dual-polymerizing resin cement showed significantly lower ΔE values than the preheated composite resin (P=.003).Conclusions.
Restoration materials and composite resin cement types used for cementation influence the amount of color change due to aging.