| By combining the dental CAD/CAM technology with elements of glass infiltration technology, a new way to fabricate all ceramic restorations was developed. In previous research, the technology of producing partially sintered porous alumina block had been solved. This study attempts to make a solution on how to match the color between glass infiltrating alumina core ceramic and the Vitadur Alpha veneering ceramic. Firstly, the effects on the color of infiltrating alumina ceramic of different metal oxides were investigated. Then, two kinds of Vita clinical shade guides and Vita In-Ceram laboratory shade guide were studied systematically; based on the study, it was found that lightness of the core material is the most important factor, followed was chroma, and the least is hue. Finally, four kinds of infiltration glass powder with specified color were developed successfully. The color and its stability of infiltration alumina ceramic were tested. The color match between alumina core ceramic and the Vitadur Alpha veneering ceramic were also tested. The physical and mechanical properties of infiltration glass and alumina core ceramic were investigated. Some progress in theory and practice of dental ceramic color match has been adieved. The results indicated:1. Density, thermal expansion coefficient, Vicker's hardness, three-point bending strength and fracture toughness of infiltration glass were 2.21g/cm3, 6.41+0-6 C-1, 6.39+0.12GPa, 112.08+10.58MPa, 2.01+0.09MPam1/2 respectively.2. Density, thermal expansion coefficient, Vicker's hardness, three-point bending strength and fracture toughness of infiltration glass ceramic were 3.88g/cm3, 7.68+10-6 C -1, 9.89+0.18GPa, 386.99+27.72MPa, 3.70+0.13MPam1/2 respectively.3. Cerium oxide could effectively enhance b value of the alumina core materials, but its ability of reducing L value and enhancing a value was a little. Combined use of cerium oxide and erbium oxide could shift the color from yellow-green to yellow-red, while it's ability of reducing L value was still weak; when the ratio of the two oxides was fixed by weight, the color parameter changes linearly with the ratio; when the overall mass by weight was fixed, the color shift corresponds to the change of mol of individual oxide. When ferric oxide was added, L value was decreased and the color was shifted to more yellow-red direction.4. Compared with Vita Classical shade guide, Vita 3D-Master extend its color in a and b, which include more yellow-reddish and more saturation color tabs. L value extends toward darker. When comparing these two color ranges with that of Chinese teeth color cards, Vita 3D-Master is more preferable to Vita Classical. The color parameters of Vita 3D-Master were L: 55.39-68.44, a: 0.52-5. 58, b: 7.22-21. 57; The color parameters of Vita In-Ceram alumina shade guide were L: 67.68-79.03, a:-0.11-3.94, b: 13.51-24.75. The L value of clinical shade guide was lower than that of laboratory shade guide. It indicated that L value of the infiltrated alumina ceramic would be reduced by applying veneering ceramic.5. After infiltration with Vita In-Ceram glass powder, regarded 1mm thickness as the standard, the color parameters of alumina core ceramic were L: 69.39-78.41, a: 1.82-4.02, b:18.35-24.42; when infiltration with No.l -No.4 glass powder, the color parameters of alumina core ceramic were L:68.80-78.44, a:1.32--4.75 , b:16.86-21.86. The color distribution of two groups were similar with Vita In-Ceram laboratory shade guide. The differences between the two groups of glass powder were: b value and chroma of the No.3 core ceramic were lower than that of AL3 core ceramic, while a value was higher; b value and chroma of the No.l and No.2 core ceramic were lower than that of AL1 and AL2 core ceramic. The reflectance curve of core ceramic infiltrated by No.l - No.4 glass powderdemonstrated the similar trend as that of the core ceramic infiltrated by Vita In-Ceram glass powder.With the increased infiltration time and elevated infiltration tempe...
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