Candido L M, Fais Lmg, Ferreira E B, Antonio S G, Pinelli Lap
Oper Dent. 2017 Jul/Aug;42(4):407-417. doi: 10.2341/16-196-L. Epub 2017 Apr 12.
To characterize the surface of an yttria-stabilized zirconia (Y-TZP) ceramic after diamond grinding in terms of its crystalline phase, morphology, mean roughness (Ra), and wettability as well as to determine a thermal treatment to reverse the resulting tetragonal to monoclinic (t-m) transformation.
Y-TZP specimens were distributed into different groups according to the actions (or no action) of grinding and irrigation. Grinding was accomplished using a diamond stone at a low speed. The samples were characterized by x-ray diffraction (XRD), scanning electron microscopy, goniometry, and profilometry. In situ high-temperature XRD was used to determine an annealing temperature to reverse the t-m transformation. Ra was submitted to the Kruskal-Wallis test, followed by the Dunn test (α=0.05). The volume fraction of the monoclinic phase and contact angle were submitted to one-way analysis of variance, followed by the Tukey test (α=0.05).
Monoclinic zirconia was observed on the surface of samples after dry and wet grinding with a diamond stone. The volume fraction of the monoclinic phase was smaller on the dry ground samples (3.6%±0.3%) than on the wet ground samples (5.6%±0.3%). High-temperature XRD showed reversion of the t-m phase transformation, which started at 700°C and completed at 800°C in a conventional oven.
Grinding with a diamond stone partially transformed the crystalline phase on the surface of a Y-TZP ceramic from tetragonal to monoclinic zirconia while simultaneously increasing the surface roughness and wettability. The t-m transformation could be reversed by heat treatment at 800°C or 900°C for 60 minutes or 1000°C for 30 minutes.
表征氧化钇稳定氧化锆（Y-TZP）陶瓷在金刚石磨削后的表面晶体相、形态、平均粗糙度（Ra）和润湿性，并确定一种热处理方法以逆转由此产生的四方相向单斜相（t-m）转变。
根据磨削和冲洗的操作（或无操作）将Y-TZP试样分为不同组。使用金刚石磨石低速完成磨削。通过X射线衍射（XRD）、扫描电子显微镜、测角法和轮廓仪对样品进行表征。采用原位高温XRD确定逆转t-m转变的退火温度。对Ra进行Kruskal-Wallis检验，随后进行Dunn检验（α=0.05）。对单斜相的体积分数和接触角进行单因素方差分析，随后进行Tukey检验（α=0.05）。
在用金刚石磨石进行干磨和湿磨后，在样品表面观察到单斜氧化锆。干磨样品上单斜相的体积分数（3.6%±0.3%）低于湿磨样品（5.6%±0.3%）。高温XRD显示t-m相变的逆转，在传统烘箱中于700°C开始并在800°C完成。
用金刚石磨石磨削使Y-TZP陶瓷表面的晶体相部分从四方氧化锆转变为单斜氧化锆，同时增加了表面粗糙度和润湿性。通过在800°C或900°C热处理60分钟或在1000°C热处理30分钟可逆转t-m转变。
