Materials design in the performance of all-ceramic crowns
Materials design in the performance of all-ceramic crowns
复制标题
DOI：
10.1016/j.biomaterials.2003.09.050
复制
发表时间：
2004-06-01
期刊：
影响因子：
14
通讯作者：
Thompson, VP
中科院分区：
文献类型：
--
作者：
Lawn, BR;Pajares, A;Thompson, VP
报告了代表牙冠基本元素的材料结构中的损害的系统研究结果。对模型的平层标本进行了测试，该样品由双层（陶瓷/聚合物）和三层（陶瓷/陶瓷/陶瓷/聚合物）配置的各种与牙本质样聚合物底物粘合到类似牙本质样的聚合物底物制造。在咬合功能的模拟中，将样品带有球形凹痕的顶部表面。使用安装在透明聚合物基板下方的摄像机系统原位观察到断裂的发作。在陶瓷顶部和底部表面诱导断裂和变形的临界载荷被视为层厚度和接触持续时间的功能。陶瓷地面的径向裂纹在相对较低的载荷下发生，尤其是在较薄的层中。断裂力学关系用于确认实验数据趋势，并根据关键变量提供临界载荷的明确依赖性：材料弹性模量，硬度，强度和韧性：几何层厚度和接触半径。更坚固，更硬，尤其是（尤其是）较强的材料表现出较高的损伤性。临界载荷在皇冠净厚度上（四次）强烈依赖。分析关系为下一代牙冠的材料设计提供了合理的基础。由Elsevier Ltd.出版。
Results from a systematic study of damage in material structures representing the basic elements of dental crowns are reported. Tests are made on model flat-layer specimens fabricated from various dental ceramic combinations bonded to dentin-like polymer substrates, in bilayer (ceramic/polymer) and trilayer (ceramic/ceramic/polymer) configurations. The specimens are loaded at their top surfaces with spherical indenters, in simulation of occlusal function. The onset of fracture is observed in situ using a video camera system mounted beneath the transparent polymer substrate. Critical loads to induce fracture and deformation at the ceramic top and bottom surfaces are measured as functions of layer thickness and contact duration. Radial cracking at the ceramic undersurface occurs at relatively low loads, especially in thinner layers. Fracture mechanics relations are used to confirm the experimental data trends, and to provide explicit dependencies of critical loads in terms of key variables: material-elastic modulus, hardness, strength and toughness: geometric-layer thicknesses and contact radius. Tougher, harder and (especially) stronger materials show superior damage resistance. Critical loads depend strongly (quadratically) on crown net thickness. The analytic relations provide a sound basis for the materials design of next-generation dental crowns. Published by Elsevier Ltd.