OBJECTIVE: The purpose of this in vitro study was to evaluate the effects of different coloring liquid shades (A2, 3M2, and 5M2) and dipping times (no dipping, 30 seconds, 60 seconds, and 90 seconds) on the color difference (ΔE00), relative translucency parameter (ΔRTP00), and 3-point flexural strength (σ) of monolithic zirconia ceramics.
METHODS: Yttria-stabilized zirconia (3Y-TZP, 3 mol%) was cut into Ø16×1.2-mm plates (n=10) and 25×4×1.2-mm bars (n=15), which were colored using 3 shades of coloring liquid at 4 dipping times. Color coordinates were measured on a gray background by using a digital spectrophotometer with an integrating sphere attachment. The color and translucency differences were evaluated using 50:50% perceptibility (PT00 and TPT00) and acceptability (AT00 and TAT00) thresholds. The 3-point flexural strengths of the bar-shaped specimens were measured using a universal testing machine and analyzed using the Weibull distribution to calculate the Weibull modulus (m) and characteristic fracture strength (σ0). The data were analyzed with the 2-way ANOVA, Kruskal-Wallis, and LSD post hoc tests (α=.05).
RESULTS: Both shade and dipping time significantly affected the color and translucency of monolithic zirconia (P<.001). The ΔE00 was above the PT00 for all groups, with only 3M2-90 and A2-60 being below the AT00. The main cause of color differences was the difference in lightness. Only A2 showed ΔRTP00 below the TPT00 (A2-30 (ΔRTP00=0.26), A2-60 (ΔRTP00=0.29), and A2-90 (ΔRTP00=0.46)). All experimental groups showed translucency differences below TAT00. In addition, only the dipping time had a significant effect on the flexural strength of zirconia (P<.001).
CONCLUSIONS: The optical properties of monolithic zirconia ceramics were affected by the shade and dipping time of the coloring liquid. The mismatch in lightness was the main reason for the color difference. The dipping time affects the flexural strength of monolithic zirconia, whereas the shade of the coloring liquid did not seem to influence flexural strength.
目的:这项体外研究的目的是评估不同着色液体色调(A2,3M2和5M2)和浸渍时间(不浸渍,30秒,60秒,和90秒)上的色差(ΔE00),相对半透明参数(ΔRTP00),整体氧化锆陶瓷的3点弯曲强度(σ)。
方法:氧化钇稳定的氧化锆(3Y-TZP,3mol%)切成Ø16×1.2mm板(n=10)和25×4×1.2mm条(n=15),在4次浸渍时使用3种着色液体着色。通过使用带有积分球附件的数字分光光度计在灰色背景上测量颜色坐标。使用50:50%可感知性(PT00和TPT00)和可接受性(AT00和TAT00)阈值评价颜色和半透明性差异。使用万能试验机测量了条形试样的3点弯曲强度,并使用Weibull分布进行了分析,以计算Weibull模量(m)和特征断裂强度(σ0)。数据用双向方差分析,Kruskal-Wallis,和LSD事后检验(α=0.05)。
结果:阴影和浸渍时间均显着影响整体氧化锆的颜色和半透明性(P<.001)。所有组的ΔE00都高于PT00,只有3M2-90和A2-60低于AT00。颜色差异的主要原因是亮度的差异。只有A2显示ΔRTP00低于TPT00(A2-30(ΔRTP00=0.26),A2-60(ΔRTP00=0.29),和A2-90(ΔRTP00=0.46)。所有实验组显示低于TAT00的半透明差异。此外,浸渍时间对氧化锆的抗折强度有显著影响(P<.001)。
结论:整体氧化锆陶瓷的光学性能受着色液的阴影和浸渍时间的影响。亮度不匹配是色差的主要原因。浸渍时间影响整体氧化锆的抗弯强度,而着色液体的阴影似乎并不影响弯曲强度。