The effect of sintering times on the transmittance and color of glass ceramic veneer:
For the type of restoration ----- restorations with severe clinical crown discoloration, a thick porcelain veneer (thickness gradient from the neck to the cut end: 0.8 / 1.0 / 1.2) is required to cover
1. The effect of multiple sintering on the transparency of the veneer---after multiple sintering, the number of crystals in the veneer increases and the volume increases, resulting in a reduction in light transmission (Within 3 times of sintering, the effect of this ratio change between crystals is small).
2. The effect of multiple sintering on the chroma of the veneer ---- After multiple sintering of the colored oxide, the pigment particles will disintegrate or melt at high temperature, and the metal ions in the colored oxide can strongly absorb ultraviolet rays, Decrease the brightness and increase the yellow-red color.
Recommendation --- When clinically performing a CAD / CAM lithium disilicate glass ceramic anterior veneer restoration with a thickness of 1 mm in the chair, if you need to modify the shape or external dyeing modification, you can adjust the color of the veneer by grasping the number of sintering. Adapt to individual clinical needs. It is best to complete the modified glaze sintering times within one or two times, so as to avoid the influence of sintering on the color of veneer tiles to a minimum.
Effect of Sintering Times on Computer Aided Design and Fabrication of Lithium Disilicate Glass Ceramic Veneers by Chairs [J]. West China Journal of Stomatology, 2017, 35(4):389-393.