Optimal sandblasting conditions for conventional-type yttria-stabilized tetragonal zirconia polycrystals
Optimal sandblasting conditions for conventional-type yttria-stabilized tetragonal zirconia polycrystals
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DOI：
10.1016/j.dental.2018.11.009
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发表时间：
2019-01-01
期刊：
影响因子：
5
通讯作者：
Matsumoto, Takuya
中科院分区：
文献类型：
--
作者：
Okada, Masahiro;Taketa, Hiroaki;Matsumoto, Takuya
Objective.为了评估喷砂条件对传统类型的氧化钇稳定的四氧化锆多晶（Y-TZP）的表面粗糙度、相变和双轴弯曲强度的影响。烧结后使用市售Y-TZP（Lava Frame，3 M Dental Products）盘（试样尺寸：直径14 mm，厚度1.2 mm）。将试样表面研磨，然后用50 μ m氧化铝颗粒在不同压力（0.20、0.25、0.30、0.35和0.40 MPa）和距离（1、5、10和20 mm）下进行喷砂处理。进行表面粗糙度测量，并拍摄扫描电子显微镜（SEM）图像进行表面表征。利用X射线衍射（XRD）分析了Y-TZP的相变过程。采用活塞-三球试验测量双轴弯曲强度。随着喷砂压力的增加，表面粗糙度显著增加，在0.40 MPa的高压下，表面出现微裂纹。与其他喷砂距离相比，最短喷砂距离（1 mm）不能有效增加表面粗糙度。研磨后观察到四斜晶系到单斜晶系的相变。随着喷砂压力的增加，相变程度增加，且与喷砂距离无关。双轴弯曲试验表明，喷砂后的样品在0.20-0.35 MPa的机械强度有所提高，最大强度为0.25 MPa。0.40 MPa喷砂处理强度较0.25 MPa喷砂处理显著降低。随着喷砂压力的增加，Y-TZP的表面粗糙度增加，但存在一个最佳喷砂压力范围，以提高双向弯曲强度。(C)2018年牙科材料学院。爱思唯尔公司出版All rights reserved.
Objective. To assess the influence of sandblasting conditions applied to conventional-type yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) on surface roughness, phase transformation, and biaxial flexural strength.Methods. Commercially available Y-TZP (Lava Frame, 3M Dental Products) disks were used after sintering (specimen dimensions: 14 mm in diameter and 1.2 mm in thickness). The surfaces of specimens were ground, and then sandblast treatments were conducted at different pressures (0.20, 0.25, 0.30, 0.35 and 0.40 MPa) and distances (1, 5, 10 and 20 mm) with 50 mu m alumina particles. Surface roughness measurements were performed and scanning electron microscopy (SEM) images were taken for surface characterizations. Phase transformation of Y-TZP was identified by X-ray diffraction (XRD). Biaxial flexural strength was measured using the piston-on-three-ball test.Results. The surface roughness increased significantly by increasing the sandblasting pressure, and microcracks were observed at high sandblasting pressure at 0.40 MPa. The shortest sandblasting distance (1 mm) was not effective to increase the surface roughness compared with other sandblasting distances. A tetragonal to monoclinic phase transformation was observed after grinding. The degree of the phase transformation tended to increase with sandblasting pressure, and significant effect was independent of the sandblasting distance. The biaxial flexural test showed improved mechanical strengths for the samples after sand-blasting at 0.20-0.35 MPa, with the maximum strength at 0.25 MPa. Sandblasting at 0.40 MPa decreased the strength as compared with 0.25 MPa.Significance. The surface roughness increased with increasing the sandblasting pressure, whereas there was an optimal sandblasting pressure range to increase biaxial flexural strength of Y-TZP. (C) 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.