Surface quality of yttria-stabilized tetragonal zirconia polycrystal in CAD/CAM milling, sintering, polishing and sandblasting processes
Surface quality of yttria-stabilized tetragonal zirconia polycrystal in CAD/CAM milling, sintering, polishing and sandblasting processes
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DOI：
10.1016/j.jmbbm.2016.08.021
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发表时间：
2017-01-01
影响因子：
3.9
通讯作者：
Yin, Ling
中科院分区：
文献类型：
--
作者：
Alao, Abdur-Rasheed;Stoll, Richard;Yin, Ling
本文研究了钇稳定的四方氧化锆多晶（Y-TZP）在CAD/CAM铣削，随后的抛光，烧结和喷砂等工艺中的表面质量（损伤，形貌和相变），用于牙齿修复。利用x射线衍射和扫描电子显微镜（SEM）对所有加工表面进行扫描，分别确定相变和分析表面损伤形貌。所有加工表面的平均表面粗糙度（R-a）和最大粗糙度（R-z）使用台式sem辅助形貌分析软件进行测量。x射线衍射图证实了烧结诱导的单斜-四方相变，而喷砂诱导的相变未被检测到。预烧结Y-TZP的CAD/CAM铣削产生非常粗糙的表面和广泛的断裂和裂纹。对磨好的预烧结表面进行简单抛光或烧结并不能显著提高其表面粗糙度（方差分析，p < 0.05）。研磨表面的烧结-抛光均不能有效提高表面粗糙度（方差分析，p < 0.05）。研磨-抛光烧结工艺产生的表面形貌最佳，R-a=0.21 +/- 0.03 mu m, R-z=1.73 +/- 0.04 mu m，达到细菌滞留阈值。建议使用较小的磨料对凹版进行喷砂，因为较大的磨料会产生可见的表面缺陷。本研究为Y-TZP的工艺选择提供了技术见解，以达到更高的恢复质量。(C) 2016 Elsevier Ltd.版权所有。
This paper studied the surface quality (damage, morphology, and phase transformation) of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) in CAD/CAM milling, and subsequent polishing, sintering and sandblasting,processes applied in dental restorations. X-ray diffraction and scanning electron microscopy (SEM) were used to scan all processed surfaces to determine phase transformations and analyse surface damage morphology, respectively. The average surface roughness (R-a) and maximum roughness (R-z) for all processed surfaces were measured using desk-top SEM-assisted morphology analytical software. X-ray diffraction patterns prove the sintering-induced monoclinic-tetragonal phase transformation while the sandblasting-induced phase transformation was not detected. The CAD/CAM milling of pre-sintered Y-TZP produced very rough surfaces with extensive fractures and cracks. Simply polishing or sintering of milled pre-sintered surfaces did not significantly improve their surface roughness (ANOVA, p > 0.05). Neither sintering-polishing of the milled surfaces could effectively improve the surface roughness (ANOVA, p > 0.05). The best surface morphology was produced in the milling-polishing sintering process, achieving R-a=0.21 +/- 0.03 mu m and R-z=1.73 +/- 0.04 mu m, which meets the threshold for bacterial retention. Sandblasting of intaglios with smaller abrasives was recommended as larger abrasive produced visible surface defects. This study provides technical insights into process selection for Y-TZP to achieve the improved restorative quality. (C) 2016 Elsevier Ltd. All rights reserved.