Strength, fracture toughness and microstructure of a selection of all-ceramic materials. Part I. Pressable and alumina glass-infiltrated ceramics
Strength, fracture toughness and microstructure of a selection of all-ceramic materials. Part I. Pressable and alumina glass-infiltrated ceramics
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DOI：
10.1016/j.dental.2003.05.003
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发表时间：
2004-06-01
期刊：
影响因子：
5
通讯作者：
Swain, MV
中科院分区：
文献类型：
--
作者：
Guazzato, M;Albakry, M;Swain, MV
目标。本研究分为两部分，旨在比较一系列全陶瓷材料的强度、断裂韧性和微观结构。在第一部分中，比较了三种热压玻璃陶瓷（IPS-Empress， Empress 2和一种新的实验陶瓷）和氧化铝玻璃渗透陶瓷（In- ceram alumina），分别采用滑铸和干压两种方法。采用三点弯曲法对每种材料的10个棒状试样（20 x 4 x 1.2 MM3）进行抗拉强度评估；采用压痕强度法测量了20个试样（20 × 4 × 2mm）的断裂韧性。数据比较采用方差分析和Sheffe事后检验（p = 0.05）。利用扫描电镜研究了各相的体积分数、晶粒的尺寸和形状、孔隙率和裂纹模式。强度（MPa）和断裂韧性（MPa m(1/2)）的平均值和标准差分别为：IPS-Empress 106(17)(1)、1.2(0.14)(1)；皇后2 306(29)(2),2.9(0.51)(2)，新型实验陶瓷303(49)(2),3.0(0.65)(2)，In-Ceram氧化铝干压440(50)(2),3.6(0.26)(2)，In-Ceram氧化铝滑块594(52)(3),4.4(0.48)(3)。上标数字相同的值无统计学差异。显微观察揭示了玻璃基体与晶相之间的关系，晶相的特性与这些玻璃陶瓷的强化和增韧机制有关。核心材料的力学性能和微观结构对全瓷修复体的临床长期性能至关重要。这项研究为临床医生提供了有关强度、断裂韧性和显微结构的数据。(C) 2003年牙科材料学会。Elsevier Ltd.出版。版权所有。
Objective. The present study, divided into two parts, aimed to compare the strength, fracture toughness and microstructure of a range of all-ceramic materials. In part 1, three hot-pressed glass-ceramics (IPS-Empress, Empress 2 and a new experimental ceramic) and alumina glass-infiltrated ceramics (In-Ceram Alumina), processed by both slip casting and dry pressing, were compared.Methods. Tensile strength was appraised on 10 bar-shaped specimens (20 x 4 x 1.2 MM3) for each material with the three-point bending method; the fracture toughness was measured from 20 specimens (20 x 4 x 2 MM), by using the indentation strength technique. Data were compared with ANOVA and the Sheffe post hoc test (p = 0.05). The volume fraction of each phase, the dimensions and shapes of the grains, porosity and the crack patterns were investigated using SEM.Results. The average and standard deviation in strength (MPa) and fracture toughness (MPa m(1/2)) were: IPS-Empress 106(17)(1), 1.2(0.14)(1); Empress 2 306(29)(2), 2.9(0.51)(2), new experimental ceramic 303(49)(2), 3.0(0.65)(2), In-Ceram Alumina dry-pressed 440(50)(2), 3.6(0.26)(2), In-Ceram Alumina slip 594(52)(3), 4.4(0.48)(3). Values with the same superscript number showed no significant statistical difference. Microscopy revealed the relationship between the glass matrix and the crystalline phase and the characteristics of the latter were correlated to the strengthening and toughening mechanisms of these glass-ceramics.Significance. The mechanical properties and microstructure of core materials have been advocated as crucial to the clinical long-term performance of all-ceramic dental restorations. This investigation provides the clinician with data regarding strength, fracture toughness and microstructure of a broad range of current materials. (C) 2003 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.