Abstract: Objective To determine whether under the Emax ceramic block with different thicknesses and different colors the light cured resin can be fully cured, to facilitate clinical Emax ceramic veneer aesthetic restoration of microdontia, teeth when reversed, and to set the maximum thickness of the stick side. Methods By using Fourier transform infrared spectroscopy,the curing rate of light composite resin of EMAX porcelain block was measured by CEREC chip with different colors (A1, A4, B1, B4, C1, C4) and different thicknesses (2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm) . Results When the illumination time was 120 s, and A1, B1, C1 color ceramic thickness was less than or equal to 2.6mm, the resin was fully cured. When A4, B4, C4 color ceramic thickness was less than or equal to 2.2 mm, the resin was fully cured. Curing rate was not statistically different between the light colored ceramics（P＞0.05）. There was a statistical difference in the cure rate between the light colored ceramic and the dark ceramic（P＜0.01）. The cure rate of the resin of dark ceramic was obviously lower than that of the light colored ceramic. Conclusion The curing rate of the resin obviously decreases with the increase of the ceramic color and the thickness, the thickness and color of Emax ceramic have obvious influence on the cure rate of light cured resin.

Key words: E-max ceramic block, light cured resin, cure rate, infrared spectroscopy