Nonaka Kazumichi, Teramae Mitsuji, Pezzotti Giuseppe
Department of Research and Development, SHOFU INC., Higashiyama-ku, Kyoto 605-0983, Japan.
Ceramic Physics Laboratory, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
Materials (Basel). 2023 Jan 11;16(2):714. doi: 10.3390/ma16020714.
The high-speed sintering of zirconia has become essential for ceramic dental prosthesis treatment in a single visit. Previous studies have shown that 5 mol% yttria-stabilized zirconia (5Y zirconia), with the exception of some types, loses strength and translucency with high-speed sintering. In this study, 0.15-0.92 wt% GaO, which is expected to promote the sintering of zirconia, was added to improve the properties of 5Y zirconia high-speed sintered bodies, and the effect of its addition was evaluated. The specimens were characterized by density and translucency measurements, a three-point bending test, X-ray diffraction (XRD), scanning electron microscopy (SEM), and shrinkage measurement. The addition of GaO improved both translucency and flexural strength of 5Y zirconia high-speed sintered bodies. XRD and SEM observations revealed that this improvement in properties was due to the change in the crystal phase composition and the decrease in the amount and size of pores due to the addition of GaO. Shrinkage measurements also revealed that the addition of GaO changed the sintering behavior of 5Y zirconia, suggesting that this change led to a reduction in porosity. From the above results, it was concluded that GaO addition is effective in improving the properties of 5Y zirconia high-speed sintered bodies.
氧化锆的高速烧结已成为单次就诊进行陶瓷牙科修复治疗的关键。先前的研究表明，除某些类型外，5摩尔％氧化钇稳定的氧化锆（5Y氧化锆）在高速烧结时会失去强度和透明度。在本研究中，添加了预期可促进氧化锆烧结的0.15 - 0.92 wt％的GaO，以改善5Y氧化锆高速烧结体的性能，并评估其添加效果。通过密度和透明度测量、三点弯曲试验、X射线衍射（XRD）、扫描电子显微镜（SEM）和收缩率测量对试样进行表征。添加GaO提高了5Y氧化锆高速烧结体的透明度和抗弯强度。XRD和SEM观察表明，性能的改善归因于晶相组成的变化以及由于添加GaO导致的气孔数量和尺寸的减少。收缩率测量还表明，添加GaO改变了5Y氧化锆的烧结行为，这表明这种变化导致孔隙率降低。从上述结果得出结论，添加GaO可有效改善5Y氧化锆高速烧结体的性能。
