Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
J Prosthodont. 2019 Feb;28(2):e563-e571. doi: 10.1111/jopr.12949. Epub 2018 Jul 12.
The aim of this in vitro study was to measure the effect of staining and artificial aging on the surface roughness of commercially available resin-ceramic computer-aided design and computer-aided manufacturing (CAD/CAM) materials both quantitatively and qualitatively and to compare it to feldspathic material.
Test specimens (n = 15 per material) were prepared of CAD/CAM ingots from a resin nanoceramic (Lava Ultimate, LVU), a polymer-infiltrated ceramic (Vita Enamic, ENA), and a resin nanoceramic (Cerasmart, CER). In the staining protocol, test specimens were (i) roughened in a standardized manner and (ii) stained with the manufacturer's recommended staining kit by means of photo-polymerization (Bluephase Polywave). The control specimens were prepared out of a feldspathic ceramic (Vita Mark II,VM2) and stained in a ceramic furnace. As negative control of each group, 15 specimens were prepared and polished in a standardized manner. Surface roughness (Ra) was measured after finishing procedures and after simulation of clinical service up to 5 years by means of toothbrushing. After each year of aging, one specimen per group was randomly selected for scanning electron microscopy (SEM) analysis. Kruskal-Wallis test and paired post-hoc test were applied to detect differences between treatment groups (alpha = 0.05).
The mean roughness measurements of the stained CAD/CAM materials were 0.14 ± 0.04 μm (ENA), 0.15 ± 0.03 μm (LVU), 0.22 ± 0.03 μm (VM2), and 0.26 ± 0.12 μm (CER). In the polished CAD/CAM materials the measurements were 0.01 ± 0.01 μm (CER), 0.02 ± 0.01 μm (LVU), 0.02 ± 0.00 μm (VM2), and 0.03 ± 0.01μm (ENA). Irrespective of the restoration material, the applied staining protocol resulted in a higher surface roughness compared to the polished specimens (p < 0.001). After 5 years of simulated aging the mean surface roughness in the stained CAD/CAM materials were 0.22 ± 0.03 μm (VM2), 0.24 ± 0.09 μm (ENA), 0.25 ± 0.06 μm (CER), and 0.37 ± 0.09 μm (LVU). Aging had a significant effect on surface roughness in groups ENA and LVU (p < 0.001). SEM analysis showed that the staining layer on resin-ceramic CAD/CAM materials was partially removed over time.
The applied staining protocol significantly increased surface roughness of CAD/CAM materials. Instability of the staining layer on resin-ceramic CAD/CAM materials could be anticipated over time as a consequence of toothbrushing, whereas feldspathic ceramic did not suffer from such aging effect.
本体外研究的目的是定量和定性地测量染色和人工老化对市售树脂陶瓷计算机辅助设计和计算机辅助制造（CAD/CAM）材料表面粗糙度的影响，并将其与长石材料进行比较。
用 CAD/CAM 铸锭制备测试样本（每种材料 15 个样本），这些铸锭来自树脂纳米陶瓷（Lava Ultimate，LVU）、聚合物渗透陶瓷（Vita Enamic，ENA）和树脂纳米陶瓷（Cerasmart，CER）。在染色方案中，测试样本（i）以标准化方式进行粗化，（ii）通过光聚合（Bluephase Polywave）用制造商推荐的染色套件进行染色。对照样本由长石陶瓷（Vita Mark II，VM2）制备，并在陶瓷炉中进行染色。作为每组的阴性对照，以标准化方式制备了 15 个样本。在完成处理程序后以及通过刷牙模拟临床服务 5 年后测量表面粗糙度（Ra）。老化后每年，每组随机选择一个样本进行扫描电子显微镜（SEM）分析。应用 Kruskal-Wallis 检验和配对后检验来检测处理组之间的差异（α=0.05）。
染色 CAD/CAM 材料的平均粗糙度测量值为 0.14±0.04μm（ENA）、0.15±0.03μm（LVU）、0.22±0.03μm（VM2）和 0.26±0.12μm（CER）。在抛光的 CAD/CAM 材料中，测量值为 0.01±0.01μm（CER）、0.02±0.01μm（LVU）、0.02±0.00μm（VM2）和 0.03±0.01μm（ENA）。无论修复材料如何，应用的染色方案都会导致表面粗糙度高于抛光样本（p<0.001）。经过 5 年模拟老化后，染色 CAD/CAM 材料的平均表面粗糙度为 0.22±0.03μm（VM2）、0.24±0.09μm（ENA）、0.25±0.06μm（CER）和 0.37±0.09μm（LVU）。老化对 ENA 和 LVU 组的表面粗糙度有显著影响（p<0.001）。SEM 分析表明，随着时间的推移，树脂陶瓷 CAD/CAM 材料上的染色层会部分脱落。
应用的染色方案显著增加了 CAD/CAM 材料的表面粗糙度。随着时间的推移，树脂陶瓷 CAD/CAM 材料上的染色层可能会不稳定，因为刷牙会导致这种情况，而长石陶瓷则不会受到这种老化影响。
