Objective: To evaluate influence of thermo-cycling, staining and whitening on color (DE*), translucency parameter (TP) and gloss (GU) of two resin-ceramics.
Method: Rectangular specimens (12×14×4mm) were cut from CEREC MC XL blocks of GC Experimental (G, GC Corp.) and Lava Ultimate (L, 3M ESPE) using a diamond saw. Surfaces were ground with 400-grit SiC paper and polished for 40 seconds. Experimental conditions (n=5) were: thermo-cycling (TC), TC + coffee staining, TC + red wine staining, TC + whitening, and control. ΔE* and DTP (Color-Eye 7000 spectrophotometer) and DGU (Novo-Curve gloss-meter) were measured. Data were analyzed by analysis of variance. Fisher's PLSD test was calculated at the 0.05 level of significance. The 50:50% acceptability threshold of DE*=3.5 was used for data interpretation.
Result: Table shows means and standard deviations for DE*, DTP1 and DGU.
Material
| Parameter
| TC
| TC + Red Wine
| TC + Coffee
| TC + Whitening
| Control
|
G
| DE*
| 0.4 (0.2)†
| 0.9 (0.3)
| 2.1 (0.6)
| 0.0 (0.5)
| 0.5 (0.1)
|
DTP
| 0.0 (0.3)
| 0.2 (0.3)
| 0.7 (0.3)
| -0.1 (0.1)
| 1.0 (1.8)
| |
DGU
| 2.8 (1.5)
| 1.9 (2.1)
| -3.0 (4.3)
| 2.4 (3.3)
| 1.8 (1.2)
| |
L
| DE*
| 0.4 (0.1)
| 1.8 (0.4)
| 2.5 (0.5)
| 0.3 (0.1)
| 0.2 (0.2)
|
DTP
| 0.2 (0.1)
| 0.7 (0.2)
| 1.5 (0.3)
| 0.1 (0.2)
| -0.2 (0.1)
| |
DGU
| 1.7 (0.8)
| 0.8 (4.8)
| -3.7 (2.9)
| 1.2 (0.8)
| 2.1 (1.1)
|
†Fisher's PLSD intervals (p<0.0001) for comparisons among 5 conditions and 2 materials specimens were: DE*, 0.28 and 0.18; DTP, 0.55 and 0.35; and DGU, 2.4.
Conclusion: GC Experimental resin-ceramic exhibited better overall color stability than Lava Ultimate upon exposure to several conditions. However, color changes were below the 50:50% acceptability threshold. Differences among materials for translucency parameter and gloss were not significant. Color, translucency parameter and gloss of both materials were stable.
Supported in part by GC Corporation