Postgraduate Program in Oral Sciences (Prosthodontics Units), Faculty of Odontology, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
Undergraduate student, Department of Restorative Dentistry, Postgraduate Program in Oral Sciences, Federal University of Santa Maria (UFSM), Santa Maria, RS, Brazil.
J Prosthet Dent. 2023 Sep;130(3):392.e1-392.e9. doi: 10.1016/j.prosdent.2023.07.002. Epub 2023 Jul 28.
The color of monolithic zirconia restorations is obtained by presintering or postsintering coloring techniques. However, studies on the differences in surface characteristics and their influence on color stability are lacking.
The purpose of this in vitro study was to evaluate the influence of shading and staining techniques for a zirconia ceramic on the surface characteristics and colorimetric parameters (color difference, translucency, and whiteness index) after exposure to coffee or red wine and then polishing.
Ceramic disks (N=30; Ø10×1mm) were allocated into 3 groups: preshaded-shaded by the manufacturer (IPS e.max ZirCAD MT, shade A2); manually shaded-unshaded zirconia (IPS e.max ZirCAD MT, bleaching shade-BL) colored by the brushing technique, before sintering; stained-unshaded zirconia (IPS e.max ZirCAD MT BL) colored by the staining technique, after sintering. Spectrophotometric color assessments ensured the same initial perceived color (Vita Classical A2) for specimens included in the study (∆E<1.77 acceptability threshold). Surface characteristics were assessed by scanning electron microscopy and atomic force microscopy. The specimens were immersed in coffee (n=5) or red wine (n=5) for 12 and 24 days and subsequently polished. The data were statistically and descriptively analyzed for color differences (∆E), translucency parameters (TP), and whiteness indexes for dentistry (WI), considering acceptability and perceptibility thresholds.
The shaded groups found an irregular ceramic surface with uniformly sized zirconia crystals. The stained group found a glass-covered smoother surface. Significant alterations in color parameters (∆E, TP, WI) were observed with immersion in pigmenting beverages (P<.001) both after 12 days, and after 24 days. The shaded specimens had greater color alterations after immersion but benefited from the polishing procedure, which reduced color differences below an acceptable threshold in comparison with the baseline. Stained specimens had lower color alterations after immersion, but the polishing protocol was detrimental as it whitened the ceramic by subsurface exposure.
The coloring technique influences the surface characteristics of zirconia ceramic and also the color parameters after exposure to colored beverages and polishing.
整体氧化锆修复体的颜色通过预烧结或后烧结着色技术获得。然而，关于表面特性的差异及其对颜色稳定性的影响的研究还很缺乏。
本体外研究的目的是评估用于氧化锆陶瓷的遮色和染色技术对暴露于咖啡或红酒后以及抛光后的表面特性和比色参数（颜色差异、半透明度和白度指数）的影响。
将陶瓷圆盘（N=30；Ø10×1mm）分为 3 组：由制造商预遮色（IPS e.max ZirCAD MT，A2 色调）；在烧结前通过刷涂技术对未遮色的氧化锆（IPS e.max ZirCAD MT，漂白色调-BL）进行手动遮色；在烧结后通过染色技术对未遮色的氧化锆（IPS e.max ZirCAD MT BL）进行染色。分光光度比色评估确保了研究中包含的样本具有相同的初始感知颜色（Vita Classical A2，∆E<1.77 可接受性阈值）。通过扫描电子显微镜和原子力显微镜评估表面特性。将样本浸入咖啡（n=5）或红酒（n=5）中 12 天和 24 天，然后进行抛光。对颜色差异（∆E）、半透明度参数（TP）和牙科白度指数（WI）的数据进行了统计和描述性分析，考虑了可接受性和可感知性阈值。
遮色组发现陶瓷表面呈不规则状，有均匀尺寸的氧化锆晶体。染色组发现玻璃覆盖的表面更光滑。浸入着色饮料后（P<.001），无论是在 12 天后还是 24 天后，观察到颜色参数（∆E、TP、WI）均有明显变化。浸泡后遮色样本的颜色变化更大，但抛光程序有助于将颜色差异降低到可接受的阈值以下，与基线相比。浸泡后染色样本的颜色变化较小，但抛光方案会使陶瓷变白，因为它会使表面下的陶瓷暴露。
着色技术会影响氧化锆陶瓷的表面特性，以及暴露于有色饮料和抛光后的颜色参数。
