Objectives: The aim of this in-vitro study was to determine the discolouration of ten restorative materials after UV-irradiation.
Methods: Eight cylindrical specimens (d=6mm, h=5mm) of each material were fabricated according to the manufacturers instructions (Elipar Trilight, 3M Espe, G, 2x40sec.). The tested materials were CeramX, Dyract AP, Dyract Extra, Esthet X, Spectrum TPH (Dentsply DeTrey, G), Filtek Z250, Sinfony (3M Espe, G), Tetric Ceram (Ivoclar-Vivadent, FL), Miris (Coltene-Whaledent, USA) and Venus (Heraeus-Kulzer, G). The discolourations were measured using the reflection spectrometer Minolta CM 3500d (Minolta, J) according to the CIE-L*a*b*-System (DIN 6174). Data were obtained after 24h, 48h and 72h of UV-irradiation with Xenotest CPS+ (Xenotest, D) (DIN 53387) in comparison to the non-irradiated specimens. The colour difference D E* was calculated using the colour values L*, a* and b*. Medians and 25%/75% percentiles were statistically analysed using the Mann-Whitney- U-Test (p=0.05).
Results:
|
D E\Mat. |
DyractAP |
DyractEx. |
EsthetX |
Miris |
Venus |
CeramX |
Z250 |
Sinfony |
Spektrum |
TetricC. |
|
24h |
1.09 |
2.05 |
2.34 |
1.86 |
1.01 |
2.02 |
1.22 |
1.33 |
2.37 |
1.39 |
|
48h |
1.92 |
2.36 |
2.37 |
2.07 |
1.45 |
2.13 |
1.23 |
1.71 |
2.47 |
1.65 |
|
72h |
1.94 |
2.59 |
2.76 |
2.54 |
2.01 |
2.72 |
1.28 |
2.00 |
2.72 |
1.80 |
Conclusion: After 72h exposition, the colour stability of Filtek Z250, Dyract AP, Sinfony, Tetric Ceram and Venus was significantly higher compared to the other materials.
All materials showed no visible discolouration (D E*<3.3) due to UV-irradiation.