Layer characteristics in strength-gradient multilayered yttria-stabilized zirconia
Layer characteristics in strength-gradient multilayered yttria-stabilized zirconia
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DOI：
10.1016/j.dental.2023.03.015
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发表时间：
2023-04-03
期刊：
影响因子：
5
通讯作者：
Zhang, Fei
中科院分区：
文献类型：
--
作者：
Inokoshi, Masanao;Liu, Hengyi;Zhang, Fei
目的：研究两种商业强度梯度多层牙科氧化锆等级的晶体学、透明度、相含量、显微结构和弯曲强度。研究了KATANA Zirconia YML（Kuraray Noritake;称为"YML";由四层组成：釉质、主体1 - 3）和IPS e.max ZirCAD Prime（Ivoclar Vivadent;称为"Prime";由三层组成：釉质、过渡、主体）。从每一层制备完全烧结的方形氧化锆试样。对各层的显微组织、化学成分、双折射参数和锆相成分进行了表征。四点和双轴弯曲强度的每一层进行了测量，使用完全烧结的酒吧和方形试样。正方形的样品被用来测量强度在layers.Results：对于这两个多层氧化锆等级，“釉质”层含有较高的量的c-ZrO 2，这导致更高的透明度，但较低的弯曲强度比“身体”层。YML "主体2"层（923 MPa）和"主体3"层（911 MPa）以及Prime "主体"层（989 MPa）的特征4点弯曲强度相当，并且高于YML "釉质"层（634 MPa）、Prime "过渡"层（693 MPa）和"釉质"层（535 MPa）。对于YML和Prime，在层间切片的样本的双轴向强度介于"釉质"和"体"层之间，这意味着界面没有形成弱连接。意义：氧化钇含量的差异影响多层氧化锆各层的相组成和机械性能。强度梯度方法允许整合具有不可调和属性的整料。
Objectives: To investigate crystallography, translucency, phase content, microstructure and flexural strength of two commercial strength-gradient multilayered dental zirconia grades.Methods: Two zirconia grades, i.e., KATANA Zirconia YML (Kuraray Noritake; referred to as "YML"; composed of four layers: enamel, body 1-3) and IPS e.max ZirCAD Prime (Ivoclar Vivadent; referred to as "Prime"; composed of three layers: enamel, transition, body) were investigated. Fully sintered square-shaped zirconia specimens from each layer were prepared. Microstructure, chemical composition, translucency parameter and zirconiaphase composition of each layer were characterized. Four-point and biaxial flexural strength of each layer was measured using fully sintered bar- and square-shaped specimens. Square-shaped samples were used to measure strength across the layers.Results: For both multilayer zirconia grades, the 'enamel' layer contains a higher amount of c-ZrO2, which resulted in higher translucency but lower flexural strength than the 'body' layers. The characteristic 4-point flexural strength of the YML 'body 2 ' (923 MPa) and 'body 3 ' (911 MPa) layers, and of the Prime 'body' (989 MPa) layer were comparable and higher than for the YML 'enamel' (634 MPa), Prime 'transition' (693 MPa) and 'enamel' (535 MPa) layers. The biaxial strength of specimens sectioned across the layers was in-between that of the 'enamel' and 'body' layers for both YML and Prime, implying the interfaces did not form a weak link. Significance: The difference in yttria content affects the phase composition and mechanical properties of each layer of the multi-layer zirconia. The strength-gradient approach allowed to integrate monoliths with irreconcilable properties.