Microstructure and nanoindentation analyses of low-temperature aging on the zirconia-porcelain interface

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• 作者：M.D. Peng ; J.Q. Wei ; Y.N. Wang ; ^{wang.yn@whu.edu.cn} ; Q. Li ; ^{li.q@whu.edu.cn}
• 关键词：Zirconia-based restorations ; Low-temperature aging ; Zirconia-porcelain interface ; Nanoindentation ; Flexural strength
• 刊名：Journal of the Mechanical Behavior of Biomedical Materials
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：66
• 期：Complete
• 页码：119-126
• 全文大小：1855 K
• 卷排序：66

文摘

The aim of the present study was to investigate the effects of low-temperature aging on the micro-mechanical and micro-structural properties of zirconia-porcelain interface. In total, thirty-three Y-TZP zirconia blocks were fabricated by using CAD/CAM technology, veneered with porcelains. Specimens were submitted to low-temperature aging in an autoclave at 134 °C, additional 0.2 MPa pressure for 0 h, 5 h, or 10 h. Flexural strength was obtained by using three-point bending test. Micro-mechanical properties (nano-hardness (H) and reduced modulus (Er)) were investigated by nanoindentation tests. Scanning electron microscopy and X-ray diffraction analyses were performed to identify the micro-structure and fracture behavior. The flexure strength, modulus and hardness of zirconia increased after 5 h aging and decreased after 10 h aging. No significant alterations of the reduced modulus or hardness of porcelain were detected in the whole aging duration. Width of the zirconia-porcelain interface was extended towards the bulk of zirconia. The detachment and cracks could be observed in zirconia, and the crystal alignment was disorganized in porcelain after 5 h aging and 10 h aging. Mechanical properties of the veneering porcelain are not affected by low-temperature aging. However, the expansion and the alterations of micro-mechanical and micro-structural properties of zirconia-porcelain interface were detected.