EFFECT OF RESIN SHADES ON OPACITY OF CERAMIC VENEERS AND POLYMERIZATION EFFICIENCY THROUGH CERAMICS
Available online 11 June 2013
Abstract
Objectives
The
aim of this study was to assess the effect of different resin cement
shades on the opacity and color difference of ceramics and to determine
the polymerization efficiency of the resin cement at different shades
after curing through ceramics.
Methods
Two different ceramics (IPSe.maxPress, and IPSEmpress®CAD,
Ivoclar Vivadent) were used for this study. A light-cured veneer luting
resin (Variolink Veneer, Ivoclar Vivadent) in four different shades of
HV + 1, HV + 3, LV-1, and LV-3 was used for the colorimetric
measurements. The colour and spectral reflectance of the ceramics were
measured according to the CIELab colour scale relative to the standard
illuminant D65 on a reflection spectrophotometer (ColorEye7000A,USA).
Colour differences (ΔE values) and the contrast ratios (CR) of
the different groups of samples were calculated. In order to analyse the
polymerisation efficiency of the resin cements, the micromechanical
properties of the resins were measured with an automatic microhardness
indenter (Fisherscope H100 C, Germany). The results were analysed using
one-way ANOVA and Tukey's HSD post-hoc tests (SPSS 18.0).
Results
The one-way ANOVA test showed that the values of ΔE and CR of the different specimen groups were significantly different (p < 0.05).
Group 1 (20.7 ± 0.5) (IPS-CAD without resin cement) exhibited the
highest and group 10 (14.8 ± 0.5)(e.max:HV + 3) exhibited the lowest ΔE
value. Significant differences in the micromechanical properties were
identified among the tested resin cements in different shades (p < 0.05).
Conclusions
Resin
cement shade is an important factor for the opacity of a restoration.
Furthermore, the resin shade affects the micromechanical properties of
the underlying resin cement.
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