Patil Ashwini, Jebaseelan Davidson
School of Mechanical Engineering (SMEC), Vellore Institute of Technology, Chennai 600127, India.
Materials (Basel). 2022 Jul 4;15(13):4685. doi: 10.3390/ma15134685.
Objective: To investigate the effect on zirconia surface of the post-fabrication surface treatments on the morphological characteristics and mechanical properties of CAD/CAM milled dental zirconia specimens as well as to identify the critical parameters in the measurement of oral retention under in vitro circumstances. Method: The zirconia specimens (N = 20, n = 4) were subjected to CAD/CAM milling and divided into five groups. The specifications were: Group G1—sintered; Group G2—sintered followed by a polishing process; Group G3—sintered followed by polishing and sandblasting with alumina particles Al2O3 (110 µm); Group G4—sintered followed by sandblasting; Group G5—sintered followed by sandblasting with polishing as the end process. All the groups were subjected to Fretting wear tests, 3-D surface roughness measurements, and Vickers’s Micro hardness tests. Investigation of the phase transformation using XRD, and surface feature examination using SEM were also carried out. Additionally, one-way ANOVA, Tukey, and Pearson correlations were statistically analysed. Results: The fabrication processes had a significant effect on the performance of zirconia specimens in all the groups (p > 0.05). Specimens that underwent polishing as the last process exhibited lower surface roughness. The monoclinic phase of zirconia was observed in all the specimens before and after wear except for those in the G2 and G5 groups, where polishing was the end process. In G5, the post-wear surface properties revealed lower surface roughness and hardness. Further, the SEM and 3-D topography show grooves as seen by the dale void volume (Vvv) values; shallow valley depth (Svk); micro craters; and wear track. Conclusion: Specimens in G5 that were subjected to multistep post-fabrication process, namely sandblasting followed by polishing, yielded better results when compared to those in the other groups (G1, G2, G3, and G4). G5 with an interlayer of alumina is recommended for clinical applications due to its enhanced surface properties, mechanical properties, and low wear.
研究制作后表面处理对计算机辅助设计/计算机辅助制造（CAD/CAM）铣削牙科氧化锆试件的形态特征和力学性能的影响，并确定体外条件下口腔固位力测量中的关键参数。方法：将氧化锆试件（N = 20，n = 4）进行CAD/CAM铣削，分为五组。具体分组如下：G1组—烧结；G2组—烧结后进行抛光处理；G3组—烧结后进行抛光并使用氧化铝颗粒Al2O3（110 µm）喷砂；G4组—烧结后进行喷砂；G5组—烧结后进行喷砂，最后进行抛光。所有组均进行微动磨损试验、三维表面粗糙度测量和维氏显微硬度测试。还使用X射线衍射仪（XRD）研究相变，并使用扫描电子显微镜（SEM）检查表面特征。此外，进行了单因素方差分析、Tukey检验和Pearson相关性统计分析。结果：制作工艺对所有组氧化锆试件的性能均有显著影响（p > 0.05）。最后进行抛光处理的试件表面粗糙度较低。除G2组和G5组（最后进行抛光处理）外，所有磨损前后的试件中均观察到氧化锆的单斜相。在G5组中，磨损后的表面性能显示出较低的表面粗糙度和硬度。此外，SEM和三维形貌显示出沟槽，如谷底孔隙体积（Vvv）值、浅谷深度（Svk）、微坑和磨损轨迹所示。结论：与其他组（G1、G2、G3和G4）相比，经过多步骤制作后处理（即先喷砂后抛光）的G5组试件效果更好。由于其增强的表面性能、力学性能和低磨损特性，推荐具有氧化铝中间层的G5组用于临床应用。
