Department of Oral Sciences, Division of Prosthodontics and Maxillo-facial Rehabilitation, University of Bologna, Via S. Vitale 59, 40125 Bologna, Italy.
J Dent. 2013 Feb;41(2):121-6. doi: 10.1016/j.jdent.2012.06.009. Epub 2012 Jul 13.
To evaluate the effect of abrading before and after sintering using alumina-based abrasives on the surface of yttria-tetragonal zirconia polycrystals. Particular attention was paid to the amount of surface stress-assisted phase transformation (tetragonal→monoclinic) and the presence of microcracks.
Pre-sintered zirconia ceramic specimens (ZirCAD; Ivoclar Vivadent) were first surface-ground flat with #600-800-1000-grit SiC paper. They were then surface-treated with different grain size abrasives before and after the sintering step. Samples that underwent no surface treatment were used as controls. For each condition, eight specimens were prepared. The physical/mechanical characteristics of zirconia material were determined by measuring density, porosity, grain size, hardness, and fracture toughness. The effects of surface treatments were assessed by surface roughness measurements, quantitative X-ray diffraction analysis, and scanning electron microscopy.
With increased dimensions of the abrasive particles, the abraded surfaces of zirconia specimens exhibited a widespread system of microcracks and an increased monoclinic zirconia quantity. These structural changes likely affect the aging of the material during its clinical service.
评估在烧结前后使用氧化铝基磨料对氧化钇稳定四方氧化锆多晶（yttria-tetragonal zirconia polycrystals，Y-TZP）表面进行研磨处理的效果。特别关注表面应力辅助相变（四方相→单斜相）的程度和微裂纹的存在。
首先将预烧结的氧化锆陶瓷试件（ZirCAD；义获嘉伟瓦登特）用 #600-800-1000 号碳化硅砂纸研磨至平面。然后，在烧结前后使用不同粒度的磨料对试件进行表面处理。未进行表面处理的试件作为对照组。每种条件下制备 8 个试件。通过测量密度、孔隙率、晶粒尺寸、硬度和断裂韧性来确定氧化锆材料的物理/力学特性。通过表面粗糙度测量、定量 X 射线衍射分析和扫描电子显微镜评估表面处理的效果。
随着磨料颗粒尺寸的增加，氧化锆试件的研磨表面出现了广泛的微裂纹系统和增加的单斜氧化锆量。这些结构变化可能会影响材料在临床使用期间的老化。
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