Fatigue of Restorative Ceramics

修复陶瓷的疲劳

• 批准号: 7755852
• 负责人: JASON A GRIGGS
• 金额: $ 28.01万
• 依托单位: UNIVERSITY OF MISSISSIPPI MED CTR
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7755852
• 关键词: Affect; Appearance; Behavior; Ceramics; Clinical; Computer software; Corrosion; Data; Dental Alloys; Dental Porcelain; Dental crowns; Dependence; Dicor ceramic; Duceram LFC; Elements; Equation; Esthetics; Exhibits; Expectancy; Failure; Fatigue; Fracture; Frequencies; Funding; Goals; Growth; Healed; Human; Individual; Kinetics; Laws; Life; Measurement; Measures; Methods; Modeling; Output; Paris, France; Population; Precipitation; Probability; Prosthesis; Reliability of Results; Reporting; Research Personnel; Resistance; Risk; Rupture; Safety; Saliva; Solutions; Specific qualifier value; Specimen; Stress; Surface; Techniques; Testing; Time; Walkers; aqueous; base; biomaterial compatibility; healing; in vivo; programs; research study; restorative ceramics; restorative dentistry; restorative material; simulation

Dental ceramics have become increasingly prolific as restorative materials because of their esthetic appearance, wear resistance, thermal insulation, and biocompatibility. Unfortunately, dental ceramics are brittle in comparison to dental alloys. This lack of fracture resistance compromises their strength and reliability, resulting in decreased lifetime expectancy. The magnitude of occlusal load rarely exceeds 324 N in humans, and finite element models have predicted these loads to induce stresses of 22 to 87 MPa in molar crowns. Traditional dental ceramics can withstand 11.6 MPa (aluminous porcelains) to 240 MPa (Dicor) of stress before single-cycle failure. In spite of this margin of safety, failure rates as high at 30% (Dicor) after seven years in vivo have been reported. Cyclic fatigue loading clearly has an impact on the maximum stress that can be withstood, and fatigue failure is rightfully a concern of dental ceramic researchers. Fatigue failure of ceramics occurs when initial flaws reach a critical stress intensity following subcritical crack growth (SCG). The overall goals of this project are to develop easier methods of measuring SCG for dental ceramics and to develop more accurate methods for predicting all-ceramic prothesis lifetimes through the following specific aims: (1) To develop a method for constructing accurate S-N-P (stress-lifetime-failure probability) models for dental ceramics from cyclic fatigue measurements on a minimum number of standard geometry specimens. (2) To develop a method for determining the individual contributions of stress corrosion and cyclic degradation to SCG for a given ceramic and stress function. (3) To verify the accuracy of prosthesis lifetimes predicted using finite element software in conjunction with time-dependent reliability software. (4) To determine how the distribution of fatigue strength relates to the distribution of single-cycle strength. (5) To determine whether crack healing through surface remodeling affects fatigue lifetime. Specific Aims 1-4 will investigate two dental ceramics: one that exhibits constant fracture toughness and one that exhibits dependence of fracture toughness on flaw size (R-curve behavior). A porcelain that exhibits crack healing behavior will be analyzed in Specific Aim 5.

牙科陶瓷由于其美观性而作为修复材料变得越来越多 外观、耐磨、隔热、生物相容性。不幸的是，牙科陶瓷 与牙科合金相比易碎。这种抗断裂能力的缺乏会损害它们的强度和 可靠性，导致预期寿命缩短。咬合负荷的大小很少超过 324 N 有限元模型预测这些载荷会在人体中产生 22 至 87 MPa 的应力 臼齿冠。传统牙科陶瓷可承受 11.6 MPa（铝瓷）至 240 MPa（Dicor） 单循环失效前的应力。尽管有这样的安全边际，但故障率高达 30% (Dicor) 已有七年体内研究报道。循环疲劳载荷显然对最大应力有影响 这是可以承受的，并且疲劳失效理所当然地是牙科陶瓷研究人员关注的问题。疲劳破坏 当亚临界裂纹扩展 (SCG) 后初始缺陷达到临界应力强度时，陶瓷就会发生裂纹。 该项目的总体目标是开发更简单的测量牙科陶瓷 SCG 的方法，并 通过以下具体方法开发更准确的方法来预测全瓷假体寿命 目标：（1）开发一种构建准确的 S-N-P（应力-寿命-失效概率）模型的方法 通过对最少数量的标准几何样本进行循环疲劳测量来获得牙科陶瓷。 (2) 开发一种确定应力腐蚀和循环的单独贡献的方法 对于给定的陶瓷和应力函数，退化为 SCG。 (3) 验证假体寿命的准确性 使用有限元软件结合瞬态可靠性软件进行预测。 (4) 至 确定疲劳强度分布与单循环强度分布的关系。 (5) 至 确定通过表面重塑进行的裂纹愈合是否会影响疲劳寿命。具体目标 1-4 将 研究两种牙科陶瓷：一种具有恒定的断裂韧性，另一种具有恒定的断裂韧性 断裂韧性对缺陷尺寸的依赖性（R 曲线行为）。具有裂纹愈合能力的瓷器 行为将在具体目标 5 中进行分析。

项目成果

Accuracy and precision of fractal dimension measured on model surfaces.

• DOI: 10.1016/j.dental.2013.11.015
• 发表时间: 2014-03
• 期刊: DENTAL MATERIALS
• 影响因子: 5
• 作者: McMurphy, Timothy B.;Harris, Christopher A.;Griggs, Jason A.
• 通讯作者: Griggs, Jason A.

Characterization of glass-infiltrated alumina-based ceramics.

• DOI: 10.1016/j.dental.2008.06.005
• 发表时间: 2008-11
• 期刊: DENTAL MATERIALS
• 影响因子: 5
• 作者: Della Bona, Alvaro;Mecholsky, John J., Jr.;Barrett, Allyson A.;Griggs, Jason A.
• 通讯作者: Griggs, Jason A.

Analysis of subcritical crack growth in dental ceramics using fracture mechanics and fractography.

• DOI: 10.1016/j.dental.2007.08.001
• 发表时间: 2008-05
• 期刊: Dental materials : official publication of the Academy of Dental Materials
• 作者: B. Taskonak;J. Griggs;J. J. Mecholsky-J.;Jiahau Yan

Effect of loading frequency on cyclic fatigue lifetime of a standard-diameter implant with an internal abutment connection.

• DOI: 10.1016/j.dental.2018.09.001
• 发表时间: 2018-12
• 期刊: Dental materials : official publication of the Academy of Dental Materials
• 作者: Duan Y;Griggs JA
• 通讯作者: Griggs JA

Flexural strength and failure modes of layered ceramic structures.

• DOI: 10.1016/j.dental.2011.09.008
• 发表时间: 2011-12
• 期刊: DENTAL MATERIALS
• 影响因子: 5
• 作者: Borba, Marcia;de Araujo, Maico D.;de Lima, Erick;Yoshimura, Humberto N.;Cesar, Paulo F.;Griggs, Jason A.;Della Bona, Alvaro
• 通讯作者: Della Bona, Alvaro