Color is a key aspect during the manufacturing process of dental prosthesis. Beside factors, such as form and translucency, color is an important aspect. In particular, veneering ceramics are frequently used. The purpose of this in vitro study was to evaluate the color characteristics of a veneering ceramic under constant test conditions.
Methods:
Six ceramic discs (Vita VM 9, Vita Zahnfabrik, Bad Säckingen, Germany) of each of the 16 colours of the VITA Classical system were manufactured using a mould. L*a*b* colour coordinates of each of these discs were measured fivefold spectrophotometrically (Thermo Scientific, Evolution 600 UV-Vis spectrophotometer equipped with an integrating sphere). The colour variations were defined by calculating the colour distances Δ E between the different discs within a series of “identical” colour categories.
Results:
The values for L*a*b* colour coordinates are seen in Table 1. The colour distances Δ E within the different colour categories are <1.
Table 1:
color |
mean L |
mean a |
mean b |
Δ E |
A1 |
74,6 |
3.3 |
9.7 |
0.5 |
A2 |
73.7 |
4.4 |
13.1 |
0.5 |
A3 |
69.9 |
4.9 |
12.2 |
0.5 |
A3.5 |
70.7 |
5.6 |
15.2 |
0.5 |
A4 |
67.6 |
6.2 |
15.9 |
0.5 |
B1 |
73.9 |
2.6 |
8.0 |
0.3 |
B2 |
74.3 |
3.7 |
12.2 |
0.4 |
B3 |
72.2 |
5.0 |
15.3 |
0.4 |
B4 |
71.9 |
5.2 |
17.1 |
0.5 |
C1 |
70.1 |
2.5 |
7.6 |
0.5 |
C2 |
69.6 |
3.8 |
11.7 |
0.6 |
C3 |
66.1 |
3.9 |
11.4 |
0.4 |
C4 |
63.2 |
4.9 |
13.1 |
0.6 |
D2 |
68.6 |
2.8 |
7.8 |
0.6 |
D3 |
69.5 |
4.5 |
11.9 |
0.5 |
D4 |
69,9 |
3.6 |
13.6 |
0.3 |
Conclusions: Within the limitations of this study the color variations within the colour categories of the Vita VM 9 ceramic are not detectable by human perception. Thus this veneering ceramic is suitable for the production of high esthetic restorations.