Method: Square-shaped specimens (0.5 mm thickness, shade A2) were fabricated from the following ceramic materials (n=10/group): CZR (Noritake), Vitablocks Mark II (Vident), e.max CAD LT (Ivoclar), e.max CAD HT (Ivoclar), Empress CAD LT (Ivoclar), e.max Press LT (Ivoclar).
Luminance (Y) was measured over black and white tiles. Color (CIE L*a*b*) was measured over black and white tiles and shade A2, A3.5, A4, B4 acrylic blocks. A spectrophotometer (Color I5, X-Rite) was used for the measurements. CR and ΔΕ were determined.
Result: Mean CR and ΔΕ for specimens over the color backgrounds are displayed below. Data were subjected to one-way and two-way ANOVA (p=0.05)
Ceramic groups |
Vitablocks Mark II |
Noritake CZR |
Empress CAD LT |
e.max Press LT |
e.max CAD LT |
e.max CAD HT |
CR % |
11.86 (1.23) |
17.95 (2.07) |
18.65 (1.48) |
20.89 (1.20) |
25.26 (2.43) |
11.66 (1.11) |
ΔΕ black-white |
53.28 (1.94) |
47.81 (3.30) |
45.19 (1.75) |
42.11 (2.02) |
40.24 (2.53) |
52.85 (1.32) |
ΔΕ A2-A3.5 |
4.84 (0.32) |
4.03 (1.06) |
3.85 (0.45) |
3.55 (0.58) |
4.01 (0.48) |
4.77 (0.20) |
ΔΕ A2-A4 |
7.28 (0.33) |
6.14 (0.99) |
6.60 (0.31) |
5.58 (0.59) |
5.75 (0.36) |
7.36 (0.27) |
ΔΕ A2-B4 |
3.58 (0.38) |
2.95 (0.97) |
2.56 (0.23) |
2.22 (0.39) |
1.99 (0.62) |
3.55 (0.47) |
Conclusion: A significant difference in masking properties among the tested ceramics was revealed over black and white backgrounds (P<0.0001). E.max® CAD LT and e.max® Press LT groups had significantly better masking properties than the others (p<0.001).
All tested ceramics exhibited poor masking properties against the A4 background.
Masking properties of most tested ceramics were more acceptable against the B4 background (ΔE≤3.3).