IADR Abstract Archives
Colour correspondence of two ceramics in two different shade guides
Objectives: The aim of this study was to compare the colour correspondence of two different ceramic system based on two different colour shade guides by the use of a clinical spectrophotometer.
Methods: one shade for each of the two ceramic systems was selected: A3 for Vita Omega 900 (Vita Zahnfabrik, Germany) based on Vitapan Classical Shade Guide and 2M3 for Vita VM13 (Vita Zahnfabrik, Germany) based on Vitapan 3D Master Shade Guide. 15 disks were fabricated for each ceramic system using a proprietary steel mould that allowed the control of the thickness of each layer. The total thickness of each specimen was 2.0mm. The thickness of the metal base disk was 0.7mm; Opaque was layered in 0.15mm. Dentin Opaque, Dentin and Enamel were then layered following manufacturer's patterns. As ceramic thickness is not always constant under clinical conditions, Dentin Opaque was layered in a 0.25mm to 0.35mm range, whereas for Dentin the range was 0.55mm-0.65mm, and for Enamel 0.20mm-0.30mm. Each layer thickness was checked after firing. Easyshade (Vita Zahnfabrik, Germany) clinical spectrophotometer was used for colour comparison. “Restoration” mode was selected in order to compare the specimen colour with the reference colour stored in the device.
Results:
Measured DE values:
|
O900 |
3.2 |
2.9 |
3.1 |
2.9 |
3.1 |
2.9 |
2.9 |
2.8 |
2.9 |
2.9 |
3.0 |
3.0 |
2.7 |
2.9 |
2.9 |
|
VM13 |
1.3 |
1.2 |
1.5 |
1.5 |
1.5 |
2.2 |
2.5 |
2.3 |
2.3 |
2.4 |
2.2 |
2.4 |
2.3 |
2.5 |
2.3 |
The independent samples t-test showed a statistically significant difference between the groups (p<0.001).
Conclusions: The specimens manufactured with Vita VM13 ceramic in Vita 3D Master shade guide showed a higher colour correspondence with standards (DE=2.05±0.49) as compared with specimens manufactured with Vita Omega 900 in Vitapan Classical shade guide (DE=2.94±0.12). This finding may be explained by the more systematic spatial distribution of 3D Master shade guide color values.