牙科修复用叠层复合陶瓷的疲劳损伤机理研究

项目名称： 牙科修复用叠层复合陶瓷的疲劳损伤机理研究

项目编号： No.50872003

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 化学工业

项目作者： 刘亦洪

作者单位： 北京大学

项目金额： 35万元

中文摘要： 本研究运用实际失效样本分析、力学实验、有限元分析、数学理论计算等综合手段，模拟口腔实际环境和应力状态，系统阐述了牙科常用叠层复合陶瓷材料接触损伤机理。明确叠层复合陶瓷材料的破坏方式及分型，证实无论单次载荷实验、疲劳实验叠层复合陶瓷的损伤方式均与全瓷修复体临床实际损伤方式相同，水环境下的慢裂纹扩展加速疲劳损伤进程。阐明全瓷修复体抗损伤能力与基底瓷和饰瓷的力学性能不匹配、界面结合、热残余应力、饰瓷与基底瓷厚度比例和几何形态、缺陷等相关。提出提高基底瓷与饰瓷之间的化学结合有利于叠层全瓷修复体抵抗界面破坏能力的提高。通过不同修复体设计方案与叠层陶瓷材料的破坏方式和抗力关系的研究，提出了优化的修复体设计方案。首次发现烧结饰瓷过程和基底冠制作过程中，由于环境的污染带来的全瓷修复体缺陷，以及对修复体力学性能的严重影响，提出生产和加工环节的质量监控和环境污染控制是提高全瓷修复体长期稳定性的一个重要方面。为现有全瓷修复材料的选择应用以及新型全瓷修复材料的研制开发提供了理论依据。将MSP测定技术应用于口腔修复材料，并初步证实这种方法用于牙科陶瓷材料力学性能评价和损伤失效分析中的可行性和有效性。

中文关键词： 牙科陶瓷;疲劳损伤;应力;损伤失效

英文摘要： Failure analysis of clinically failed ceramic restorations, mechanical testing, finite elements analysis, and mathematics calculation were applied to elucidate the contact damage mechanism, and to define the damage pattern of the bilayer ceramic compositions. It was confirmed that the bilayer ceramic discs/beams had same damage pattern with clinical failed bilayer ceramic crowns whatever under single load or fatigue load, and the fatigue damage processes were accelerated by slow cracks growth in water environments. The damage resistance abilities of the ceramic restorations were elucidated having relationship with the mechanical properties mismatch of core ceramic and porcelain, interface bonding of core ceramic and porcelain, thermal residual stress, the thickness ratio and shape of core ceramic and porcelain, and defects. The optimization restoration designs were proposed through the analyzing the damage pattern and load resistance of bilayer ceramic compositions. The restoration defects linked to porcelain firing and cooping production were found for the first time, the serious influence of these defects to the mechanical properties of the ceramic restorations were analyzed, and taking the conclusion that special care should be taken to avoid contamination during the ceramic core fabrication and veneering processes. All these research findings provided the theory basement for the clinical application of the ceramic restorations and the manufacture of new dental ceramics. The MSP testing method was applied in the detection of dental materials, and the feasibility and significance of the test in the mechanical properties and damage analysis of dental ceramic were confirmed.

英文关键词： dental ceramic; fatigue damage; stress; fracture failure