Objective:
Translucency is besides color one of the most important parameters to describe the aesthetic appearance of dental materials. Aim of this study was to quantify the light transmission of various dental grade zirconia ceramics.
Methods:
The transmission of seven CAD / CAM zirconia core materials and a new experimental zirconia were tested in a spectrometer (S2000, Ocean Optics, USA) with a tungsten halogen light source (HL-2000 Mikropack, Germany) and an integrating Ulbricht sphere. Plane-parallel samples of 1.0 mm thickness (+- 0.02 mm) were prepared by surface grinding and final polishing with 1 µm diamond suspension. The transmission coefficients (t [%]) for light wavelengths (l [nm]) from 380 to 800 nm were measured and a physiological weighted overall transmission value (T) was calculated by integration ∫380-800 t(l) dl.
Results:
The results of the overall transmission values are given in the table below:
Zirconia Type | 3M Espe Experimental Zirconia | 3M Espe Lava Frame | Ivoclar ZirCAD | Sirona inCorisZI | Vita In-Ceram YZ-55 | Kavo Everest | Wieland ZENO | DeguDent Cercon |
Mean Value of T | 3197 | 3034 | 2775 | 2748 | 2734 | 2725 | 2511 | 1837 |
Standard Deviation | 4 | 3 | 23 | 5 | 6 | 5 | 20 | 4 |
Conclusion:
One-way ANOVA revealed significant (p<0.05) differences between the overall transmission values depending on zirconia ceramic type in the reproducibility tests (n=5). The experimental zirconia has shown a significant higher (p<0.05) transmission compared to all other tested materials with Fishers least significant difference (LSD) method. Lava Frame was significant higher (p<0.05) compared to the other commercial CAD / CAM zirconia materials tested with Fishers LSD method.