Method:
30 non-carious human mandibular molar teeth were used in this study. Teeth were embedded in chemically cured acrylic resin blocks up to 2 mm below the cemento-enamel junction. Standard Class I inlay cavities were prepared and teeth were randomly divided into 3 groups (n=10): (1) feldspathic-ceramic (CEREC Blocks, Sirona) group; (2) resin nano-ceramic (Lava Ultimate, 3M ESPE) group; (3) Leucite glass-ceramic (IPS Empress CAD, Ivoclar Vivadent) group. After making CEREC optical impressions, restorations were designed (CEREC SW 4.0, Sirona) and milled (CEREC inLab MC XL, Sirona). The inlays were adhesively cemented with a dual polymerizing resin cement (Rely X Ultimate, 3M ESPE) and left in distilized water at room temperature for a week. Color measurements were determined using a spectrophotometer (Konica Minolta, Konica Minolta Sensing, INC) before and after accelerated aging in a weathering machine with a total energy of 150 kJ/m2. Changes in color (ΔE, ΔL Δa, Δb, ΔC) were obtained using the CIE L*a*b* system. The results were submitted to one-way ANOVA, Tukey HSD test (p = 0.05).
Result: All the materials showed color changes in ranged from 0.85 to 10.21. The highest color change was attributed to resin nano-ceramic material and it’s not clinically acceptable (ΔE > 3.3). No significant difference was found in ΔL and Δa values between test groups.
Conclusion: The accelerated aging led to color changes in all the evaluated materials. All CAD/CAM inlays became darker in appearance, more saturated, a little reddish and more yellow.