Abstract:Polymer-infiltrated-ceramic composites have already shown mechanical properties comparable to that of natural tooth. Composites with gradient mechanical properties as that of the natural tooth have seldom been fabricated. The aim of this work was to examine the gradient mechanical properties of natural tooth and fabricate polymer-infiltrated-ceramic to simulate simulate natural tooth and its mechanical behaviors. The elastic modulus and Vickers hardness of enamel and dentin were examined through nano indentation, which showed gradient characteristics. There were great differences in the mechanical properties of resin infiltrated partially sintered sodium aluminum silicate, alumina and zirconia. The gradient change of mechanical properties was realized through gradually changing the ceramic component. The one is nano glass phase aluminum silicate sodium-micron α alumina laminated composites. The sintering temperature of ceramic green body is 700 °C. The holding hours are 2, 4 and 6 hours respectively. Flexural strength, fracture toughness, elastic modulus and hardness of the composite were tested, which show that elastic modulus and hardness of the aluminum silicate sodium-alumina composite exhibited gradient characteristics. Another is 3Y-PZT-micron α alumina laminated composites. The sintering temperature of green body is 1150 °C and 1200 °C, with holding time of 2 hours. The results showed that both elastic modulus and hardness exhibited gradient characteristics. SEM observation shows that an interlocking grid structure was formed in transition zone. Different from those of ordinary homogeneous materials, composites prepared in this study have anisotropy. And therefore, the mechanical properties of the composites are more close to the primary teeth.