Methods: The A1 shade of two different ceramics (IPS e.max Press, Ivoclar Vivadent; IPS Empress®CAD, Ivoclar Vivadent) of 1 mm in thickness were used for this study. A light-cured veneer luting resin (Variolink Veneer, Ivoclar Vivadent) was used at four different shades of HV +1, HV +3, LV -1 and LV -3 for the colorimetric measurement. The composites were cured by using a LED-unit (Bluephase®, Ivoclar Vivadent) at 20 seconds under the two different ceramics. The color and spectral reflectance of the ceramics were measured according to the CIELab color scale relative to the standard illuminant D65 on a reflection spectrophotometer (Color Eye 7000A, USA). The ceramics were measured over a black and a white background. Differences between measurements were calculated as ΔE.Results were statistically analyzed (SPSS 18.0).
Results: One-way ANOVA showed that the ΔE values of the groups were significantly different (p<0.05). IPS.CAD ceramic without luting resin exhibited the highest (20.7±0.5) and e.max ceramic with HV +3 resin (14.8±0.5) exhibited the lowest ΔE values. There were statistically no difference between IPS.CAD ceramic without luting resin, and IPS.CAD ceramic with HV +1 (20.5±0.5), with LV -1 (19.9±0.5), and with LV -3 (19.5±0.5).
Conclusions: Luting resin is an important factor for the final color of the restoration and therefore, clinicians should consider to use try-in pastes or shade guides to compensate the color change.