Methods: Six ceramic discs of each veneering ceramic (e.max Ceram Ivoclar Vivadent AG, Schaan, Lichtenstein; HeraCeram Zirkonia, Heraeus Kulzer GmbH, Hanau, Germany; Shofu Vintage ZR, Shofu INC., Kyoto, Japan) and each 16 colours of the VITA Classical system were produced using a mould. CIE L*a*b* color coordinates of each of these discs were measured fivefold using the Vita Easyshade Advanced (VITA Zahnfabrik H. Rauter GmbH & Co. KG.. Bad Säckingen. Germany) spectrophotometer. Further the colour variations were defined by calculating the colour distances ΔE between the different discs within a series of “identical” colour categories.
Results: The colour distances Δ E within the different colours are in the range from 0.32 to 3.92.
E.max_Ceram ΔE:A1=2.39;A2=2.19;A3=1.14;A3,5=2.27;A4=1.17;B1=1.88;B2=1,66;B3= 1.49;B4=1.32;C1=1.27;C2=1.19;C3=1.82;C4=2.03;D2=1.47;D3=2.25;D4=1,74;ΔEmean{A1-D3}=1.71
Heraceram_Zirkonia ΔE:A1=1.86;A2=1.78;A3=1.76;A3,5=1.97;A4=1.11;B1=3.79;B2=1.73;B3=3.84;B4=3.32; C1=2.45;C2=3.92;C3=3.22;C4=3.44;D2=2.59;D3=3.33;D4=1.87;ΔEmean{A1-D3}=2.63
Shofu_Vintage ZR ΔE:A1=0.40;A2=0.53;A3=0.55;A3,5=0.39;A4=0.65;B1=0.32;B2=0.35;B3=0.63;B4=0.59;C1=0.44;C2=0.47;C3=0.50:C4=0.63;D2=0.47;D3=0.40;D4=0.40;ΔEmean{A1-D3}=0.48
Conclusions: Within the limitations of this in vitro study, there were different results regarding the color variations both between the different ceramic materials tested and between the series of color categories within one ceramic material.