Analysis of linearity between light transmittance and color value of three different brands of zirconia ceramics / 第二军医大学学报

ABSTRACT

Objective To analyze the relationship between the light transmittance and the color value of 3 different brands of zirconia dental ceramic materials of various thicknesses and colors, so as to provide evidence for a new indicator to the Colorimetric system to better simulate the natural dentin color. Methods X-rite color i7 spectrophotometer was used to measure the transmittance and reflectance (L*, a*, b*) of three brands (Lava, Upcera, Doceram) of zirconia ceramic materials of different colors and different thicknesses (0.9, 0.6 and 0.3 mm). The results were analyzed by SPSS18.0 software to investigate the linearity of transmittance with thickness and color values of the materials. Results The transmittance was not significantly different among the three brands of zirconia ceramic materials (P>0.05); the transmittance ranges of different thicknesses of zirconia ceramic (0.9, 0.6 and 0.3 mm) were 13.63%-27.47%, 18.05%-33.96%, and 25.24%-39.73%, respectively, showing significant difference (P<0.05). There was a linear relation of the transmittance with the thickness and color values of the three brands of zirconia ceramic materials UpceraTT=0.366×L*-thickness×0.661-0.280×b*; Doceram TT=0.524×L*-0.536×thickness-0.237×b*; Lava TT=0.210×L*-0.610×thickness-0.164×b*. Conclusion The transmittance ranges of the three brands of zirconia ceramic material are similar. The transmittance decreases with increase of its thickness and increases with luminance increase. Bluer zirconia ceramic has higher transmittance. Therefore, introduction of transmittance value for ceramic restoration process is important to redefine the natural tooth color perception and representation.