To evaluate light transmission of various laminate veneer materials, spectral transmittance, and the value of L*a*b* using transmitted light and luminous transmittance were determined. The results were as follows:
1. Porcelain
In short wavelength light, i.e., violet to blue light, transmittance decreased conspicuously. Spectral and luminous transmittance decreased as thickness of masking dentin increased.
2. Dicor
The difference between spectral and luminous transmittance due to presence or absence of white layer was slight, and the decrease of transmittance in short wavelength light was little. By applying shading porcelain, transmittance decreased.
3. IPS Empress
In luminous transmittance, light was transmitted more in the order of Ti, T2, O1, and O2. After staining, decrease of transmittance in short wavelength light was greater than that before staining.
4. Comparison between different types of materials
In all of the three types of materials, transmittance decreased in short wavelength light, and the difference of transmittance was noted at this site. In luminous transmittance, light was transmitted more in the order of Dicor, Porcelain, and IPS Empress.
