Viscoelastic Modeling Aided Experimental Optimization toward Fracture-Resistant Porcelain-Veneered Zirconia and Lithium Disilicate Restorations

粘弹性模型辅助抗裂瓷贴面氧化锆和二硅酸锂修复体的实验优化

• 批准号: 9754110
• 负责人: JEONGHO KIM
• 金额: $ 37.06万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9754110
• 关键词: Acute; Anatomy; Behavior; Cells; Ceramics; Clinical; Computing Methodologies; Dental Enamel; Dental Porcelain; Dental Prosthesis; Dental Veneer Application; Dental crowns; Dentin; Development; Elements; Engineering; Esthetics; Failure; Fatigue; Fracture; Goals; Healthcare; High temperature of physical object; Incidence; Knowledge; Laboratories; Lithium; Longevity; Measurement; Mechanics; Medical; Metals; Methodology; Methods; Modeling; Morbidity - disease rate; Motion; Oral cavity; Oxides; Procedures; Process; Prosthesis; Prosthesis Design; Public Health; Quality of life; Research; Residual state; Resistance; Solid; Stress; Stress Fractures; Structure; System; Testing; Time; Work; clinically relevant; cost; design; experience; improved; innovation; knowledge base; next generation; novel; predictive modeling; premature; restoration; restorative dentistry; simulation; viscoelasticity; zirconium oxide

Project Summary/Abstract Dental crowns and bridges are usually constructed by applying an esthetic porcelain veneer to a strong core. Ceramic core materials, such as zirconia and lithium disilicate, are currently favored for their ease of fabrication and for their strength. While porcelain chipping and fractures are observed in all types of veneered dental prostheses, they are particularly prevalent in porcelain-veneered zirconia. The high chipping/fracture rate is due predominantly to residual stresses introduced by the high-temperature veneering process. However, comprehensive knowledge of key material, design, and processing parameters that govern residual stresses remains obscure. The long-term goal of this project is to improve the fracture resistance of porcelain-veneered prostheses through the reduction of deleterious residual tensile stresses, in conjunction with superior design of a graded veneer/core interface. Accordingly, the overall objectives in this application are to develop a rigorous viscoelastic graded finite element method to guide the design of next-generation fracture-resistant porcelain- veneered ceramic prostheses, and to use clinically relevant fracture mechanics test methods to validate finite element model predictions. The central hypothesis is that the incidence of chipping and fracture of porcelain- veneered ceramics can be reduced to the levels seen in porcelain-fused-to-metal prostheses, through the optimization of material, design, and processing parameters. This hypothesis is formulated on the basis of preliminary results produced in the applicants' laboratories. To test this hypothesis, we will pursue two specific aims: (1) Develop a rigorous viscoelastic graded finite element model, and use this model to optimize the residual stress profile in anatomically-correct porcelain-veneered prostheses through the tailoring of material, design, and processing parameters. Validate model predictions against direct measurement using the Vickers microindentation method; (2) Experimentally quantify resistance to veneer chipping and fracture of porcelain- veneered prostheses with optimal material, design, and processing parameters relative to their bilayer counterparts and a commercial porcelain-fused-to-metal restoration, using edge-chipping methodology and mouth-motion fatigue testing. The approach is innovative because it departs from the status quo by developing a novel viscoelastic graded finite element method and utilizing this model to design continuously graded veneer/core interfaces. The proposed research is significant because it vertically advances the understanding of how stress profiles in all-ceramic prostheses can be tailored for better fracture resistance. Ultimately, such knowledge will bring us closer to a solution of a pervasive clinical problem—chipping, delamination and fracture of porcelain veneered prostheses—leading to reduced morbidity of dental prostheses and cost of replacement to the public.

项目总结/摘要 牙冠和牙桥通常是通过在坚固的核上涂上美观的瓷贴面来建造的。 陶瓷型芯材料，如氧化锆和二硅酸锂，目前受到青睐，因为它们易于制造 和力量虽然在所有类型的贴面牙中都观察到瓷崩和断裂， 在修复体中，它们在瓷贴面氧化锆中特别普遍。高碎裂/断裂率是 这主要是由于高温贴面工艺引入的残余应力。然而，在这方面， 掌握控制残余应力的关键材料、设计和工艺参数的全面知识 仍然模糊。本项目的长期目标是提高瓷贴面的抗断裂性能 通过减少有害的残余拉伸应力，结合上级设计， 分级的单板/芯界面。因此，本申请的总体目标是开发严格的 粘弹性梯度有限元法指导下一代耐瓷设计 贴面陶瓷假体，并使用临床相关的断裂力学测试方法，以验证有限 元素模型预测中心假设是瓷的碎裂和断裂的发生率- 贴面陶瓷可以减少到金属烤瓷修复体的水平， 优化材料、设计和工艺参数。这一假设是根据以下几点提出的： 申请人实验室得出的初步结果。为了验证这一假设，我们将追踪两个具体的 目的：（1）建立一个严格的粘弹性梯度有限元模型，并利用该模型对混凝土结构进行优化设计。 通过裁剪材料， 设计和工艺参数。与使用维氏硬度计直接测量的对比， 显微压痕法;（2）实验量化瓷的抗贴面剥落和断裂性能- 具有与双层相关的最佳材料、设计和加工参数的贴面修复体 对应物和商业瓷熔金属修复体，使用边缘切削方法， 口动疲劳测试这种方法是创新的，因为它通过发展 提出了一种新的粘弹性梯度有限元方法，并利用该模型设计了连续梯度 单板/核心接口。拟议的研究是重要的，因为它垂直推进的理解， 全瓷修复体中的应力分布如何定制以获得更好的抗断裂性。最终，这样的 知识将使我们更接近于一个普遍的临床问题的解决方案-缺口，分层， 瓷贴面修复体的断裂-导致牙科修复体的发病率和成本降低 更换为公众。