具有梯度特性的齿科修复复合材料制备及表征

Fabrication and characterization of dental restorative composites with gradient properties

摘要:

聚合物渗透陶瓷复合材料已经显示出与天然牙齿相似的力学性能。具有天然牙齿的梯度力学性能的复合材料很少被报道过。本工作的目的是研究原生牙齿的梯度力学性能,制备聚合物渗透陶瓷,模拟天然牙的力学行为。采用纳米压痕法测定了牙釉质和牙本质的弹性模量和维氏硬度,结果表明,原生牙齿的力学性能具有梯度特性。部分烧结硅酸钠、氧化铝和氧化锆树脂的力学性能有很大差异。通过逐步改变陶瓷组分,实现了力学性能的梯度变化。一种是纳米玻璃相硅酸铝钠/微米α氧化铝层合复合材料。陶瓷坯体的烧结温度为700 ℃,保温时间分别为2 h、4 h和6 h。对复合材料的抗弯强度、断裂韧性、弹性模量和硬度进行了测试,结果表明：硅酸铝钠铝复合材料的弹性模量和硬度呈现梯度特性。另一种是3Y-PZT-微米α氧化铝层合复合材料.坯体烧结温度分别为1150 ℃和1200 ℃,保温时间为2h。结果表明：弹性模量和硬度均呈现梯度特性。SEM观察表明,过渡区形成了相互咬合的网格结构。与普通均匀材料不同,本研究制备的复合材料具有各向异性。因此,复合材料的力学性能更接近于原生牙齿。

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.