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: 10273914
• 负责人: JEONGHO KIM
• 金额: $ 45.71万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-30 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10273914
• 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.

项目概要/摘要 牙冠和牙桥通常是通过在坚固的核心上应用美观的瓷贴面来构建的。 陶瓷芯材料，例如氧化锆和二硅酸锂，目前因其易于制造而受到青睐 以及它们的强度，而在所有类型的贴面牙科中都观察到瓷器碎裂和断裂。 修复体中，这种现象在氧化锆瓷贴面中尤为常见，其碎裂/断裂率较高。 主要是由于高温饰面工艺引入的残余应力。 对控制残余应力的关键材料、设计和加工参数的全面了解 该项目的长期目标是提高瓷贴面的抗断裂性。 通过减少有害的残余拉应力，结合卓越的设计 因此，该应用程序的总体目标是开发严格的单板/核心接口。 粘弹性梯度有限元法指导下一代抗断裂瓷的设计 贴面陶瓷假体，并使用临床相关的断裂力学测试方法来验证有限 元素模型预测的中心假设是瓷器碎裂和断裂的发生率。 贴面陶瓷可以减少到瓷熔金属假体的水平，通过 该假设是在材料、设计和加工参数的基础上制定的。 申请人实验室得出的初步结果 为了检验这一假设，我们将追求两个具体的结果。 目标：（1）建立严格的粘弹性分级有限元模型，并利用该模型来优化 通过材料的定制，在解剖学上正确的瓷贴面假体中产生残余应力分布， 使用维氏硬度计根据直接测量验证模型预测。 显微压痕法；（2）通过实验量化陶瓷的抗单板碎裂和断裂性能 相对于其双层具有最佳材料、设计和加工参数的贴面假体 单位和商业瓷熔金属修复体，使用边缘切削方法和 该方法是创新的，因为它通过开发来脱离现状。 一种新颖的粘弹性分级有限元方法并利用该模型进行连续分级设计 所提出的研究很重要，因为它垂直地推进了理解。 最终，如何调整全陶瓷假体的应力分布以获得更好的抗骨折能力。 知识将使我们更接近解决普遍存在的临床问题——碎裂、分层和 瓷贴面假体的断裂——导致假牙的发病率和成本降低 向公众更换。