Toma Flavia Roxana, Bîrdeanu Mihaela Ionela, Uțu Ion-Dragoș, Vasiliu Roxana Diana, Moleriu Lavinia Cristina, Porojan Liliana
Department of Dental Prostheses Technology (Dental Technology), Center for Advanced Technologies in Dental Prosthodontics, Faculty of Dental Medicine, "Victor Babeș" University of Medicine and Pharmacy Timișoara, EftimieMurgu Sq. No. 2, 300041 Timisoara, Romania.
National Institute for Research and Development in Electrochemistry and Condensed Matter, 300569 Timisoara, Romania.
Materials (Basel). 2022 May 18;15(10):3606. doi: 10.3390/ma15103606.
(1) Background: The purpose of this study was to evaluate the differences in terms of surface characteristics (roughness, topography, microhardness) among layers for multi-layered high translucent and super-high translucent zirconia and the influence of finishing and aging on surface characteristics and microstructure. (2) Methods: Three types of translucent multilayer zirconia were evaluated: STML (4Y-TZP); IPS e.maxZirCAD CEREC/in Lab MT Multi (4Y-TZP + 5Y-TZP); CeramillZolidfx ML (5Y-TZP). Ninety-six plate-shaped samples (32 for a material), 16 mm × 14 mm × 1 mm size, were cut with a precision disc, polished on both sides with sand papers and sintered respecting the manufacturer’s protocol. Half of the specimens (16) were finished by polishing and the other half by glazing and then equally divided into one control group and one group subject to aging by autoclaving (1 h, 134 °C, 0.2 MPa), resulting in four groups of eight samples, for each zirconia. The specimens were evaluated in three areas: cervical, medium, incisal-of each glazed or polished surface, before and after aging. Tests were performed to determine the surface roughness using a profilometer; the surface topography by an atomic force microscope (AFM) and a scanning electron microscope (SEM). Microhardness was recorded using a microhardness tester. Statistical analyses were performed using two-way ANOVA test, unpaired sample t-Test, paired sample t-Test (α = 0.05) and Pearson’s correlation. (3) Results: Before and after autoclaving, for glazed samples significance (p < 0.05) higher surface roughness, respectively lower microhardness in comparison with the polished group was assessed. No significant differences (p > 0.05) were reported between the three areas, on glazed or polished surfaces of a material. Although, after aging an increase in surface roughness was observed both on glazed and polished samples, statistical differences were found for STML (p < 0.05). No significant differences (p> 0.05) concerning microhardness among the same areas, on glazed and polished surfaces, recorded before and after aging, except CeramillZolidfx ML glazed samples. (4) Conclusions: For tested zirconia materials no significant differences among layers were registered regarding surface characteristics. Surface treatment (glazing or polishing) has a significant impact on surface roughness and microhardness. Both before and after aging, the surface roughness values for the glazed samples were higher than for those polished. The super translucent 4Y-TZP material was more affected by aging compared to the super-high translucent 5Y-TZP material. The combined material revealed similarities for each layer corresponding to the microstructure.
(1) 背景：本研究的目的是评估多层高透和超高透氧化锆各层之间在表面特性（粗糙度、形貌、显微硬度）方面的差异，以及修整和老化对表面特性及微观结构的影响。(2) 方法：评估了三种类型的半透明多层氧化锆：STML（4Y-TZP）；IPS e.maxZirCAD CEREC/in Lab MT Multi（4Y-TZP + 5Y-TZP）；CeramillZolidfx ML（5Y-TZP）。用精密圆盘切割出九十六个板状样品（每种材料32个），尺寸为16 mm×14 mm×1 mm，两面用砂纸抛光，并按照制造商的方案进行烧结。一半样品（16个）通过抛光进行修整，另一半通过上釉进行修整，然后将其平均分为一个对照组和一个通过高压灭菌进行老化的组（1小时，134°C，0.2 MPa），每种氧化锆形成四组，每组八个样品。在老化前后，对每个上釉或抛光表面的颈部、中部、切端三个区域的样品进行评估。使用轮廓仪测定表面粗糙度；通过原子力显微镜（AFM）和扫描电子显微镜（SEM）测定表面形貌。使用显微硬度测试仪记录显微硬度。使用双向方差分析测试、非配对样本t检验、配对样本t检验（α = 0.05）和皮尔逊相关性进行统计分析。(3) 结果：在高压灭菌前后，与抛光组相比，评估发现上釉样品的表面粗糙度显著更高（p < 0.05），显微硬度分别更低。对于一种材料的上釉或抛光表面，三个区域之间未报告有显著差异（p > 0.05）。尽管在老化后，上釉和抛光样品的表面粗糙度均有所增加，但STML材料存在统计学差异（p < 0.05）。除了CeramillZolidfx ML上釉样品外，在老化前后记录的上釉和抛光表面相同区域的显微硬度没有显著差异（p > 0.05）。(4) 结论：对于测试的氧化锆材料，各层之间在表面特性方面未记录到显著差异。表面处理（上釉或抛光）对表面粗糙度和显微硬度有显著影响。在老化前后，上釉样品的表面粗糙度值均高于抛光样品。与超高透5Y-TZP材料相比，超透4Y-TZP材料受老化影响更大。复合材 料各层的微观结构显示出相似性。
