High Toughness Textured Ceramics for Biomedical Use

生物医学用高韧性织构陶瓷

• 批准号: 6778107
• 负责人: Isabelle L Denry
• 金额: $ 24.85万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6778107
• 关键词: X ray crystallography; aluminum; biomaterial development /preparation; ceramics; crystallization; dental materials; glass; heat; lanthanum; mechanical stress; metal dental material; phosphates; potassium; scanning electron microscopy; surface coating

DESCRIPTION: There is a high demand in dentistry for ceramics that combine high strength and optical properties matching those of natural teeth, and in reconstructive surgery for bioactive ceramics with improved toughness. Our previous work has led to the development of a novel glass-ceramic that is pressable using conventional laboratory techniques. This material exhibits a textured microstructure and improved toughness. The overall objective of this proposal is to develop a dental glass-ceramic that combines high strength and excellent esthetics. An additional goal is to produce bioactive ceramics with improved toughness. Toughness in textured materials is directly related to the degree of texture and microstructure. Our approach to producing high strength dental ceramics is to optimize the texture, promote the nucleation of a submicroscopic secondary mica phase and reduce flaw density and size in the pressed product. Texture refinement will be achieved via two techniques: heat treatment in a temperature gradient followed by heatpressing or heat treatment of the glass after heat-pressing. Microstructure will be tailored by adding AIPO4 as a nucleating agent. Translucency will be improved by adding La203 to increase the refractive index of the glassy matrix, thereby reducing the mismatch between the indices of crystalline and glassy phases. Reduction in flaw density and size will be achieved by eliminating the surface layer present after pressing and by heat treatment of the pressed ceramic to promote crack healing. Textured bioactive ceramics with improved toughness will be produced via heat pressing. The crystallization behavior and thermal properties will be studied by thermal analysis, XRD and SEM. The degree of texture will be investigated by SEM and XRD. The surface layer will be analyzed by X-ray reflectometry and EDS. The mechanical and optical properties will be measured on textured, non-textured and commercially available ceramics as controls. The experimental design uses an adaptive sampling scheme to optimize the optical and mechanical properties and integrate the different aims. Potential applications include dental restorations, dental implant superstructures, and bone replacement implants.

描述：牙科的需求量很高，陶瓷的需求很大，可以将高强度和光学特性与天然牙齿相匹配，以及对韧性改善的生物活性陶瓷的重建手术。我们以前的工作导致了一种新型的玻璃陶瓷的发展，该玻璃陶瓷可以使用常规实验室技术压力。该材料表现出质感的微观结构和改善的韧性。该提案的总体目的是开发一种结合高强度和出色美学的牙科玻璃陶瓷。另一个目标是生产具有改善韧性的生物活性陶瓷。纹理材料的韧性与纹理和微观结构的程度直接相关。我们产生高强度牙齿陶瓷的方法是优化质地，促进次要次级云母相的成核，并降低压力机中的缺陷密度和大小。将通过两种技术来实现质地的细化：在温度梯度中进行热处理，然后在热压后进行热压或热处理。微观结构将通过添加AIPO4作为成核剂来定制。通过添加LA203来增加玻璃基矩阵的折射率，从而减少了晶体和玻璃相和玻璃相之间的不匹配，从而改善了透明度。通过消除按压后的表面层和对压制陶瓷的热处理以促进裂纹愈合，可以实现斑点密度和大小的降低。质感的生物活性陶瓷具有改善的韧性将通过热压产生。结晶行为和热性能将通过热分析，XRD和SEM研究。 SEM和XRD将研究质地的程度。表面层将通过X射线反射仪和EDS分析。机械和光学性能将以纹理，非纹理和市售的陶瓷作为对照来测量。实验设计使用自适应采样方案来优化光学和机械性能并整合不同的目标。潜在的应用包括牙科修复体，牙科上层建筑和骨骼置换植入物。