Dental Research Center, Dentistry Research Institute, Restorative Dentistry Department, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Color Imaging and Color Image Processing Department, Institute for Color Science and Technology (ICST), Tehran, Iran.
Clin Exp Dent Res. 2020 Dec;6(6):693-699. doi: 10.1002/cre2.325. Epub 2020 Sep 9.
Creating a tooth-like appearance by use of dental ceramics is still a challenge. Opalescence is a unique property of dental enamel, attempted to be mimicked by dental restorative materials. This study aimed to assess the effect of ceramic thickness on opalescence.
Twenty-four discs were fabricated of feldspathic ceramic, IPS e.max, zirconia and Enamic ceramics with 10 mm diameter and 0.5 and 1 mm thicknesses (n = 12). The opalescence of ceramic specimens was calculated by measuring the difference in yellow-blue axis (CIE ∆b*) and red-green axis (CIE ∆a*) between the transmitted and reflected spectra. One-way ANOVA was applied to compare the opalescence of different ceramic specimens with variable thicknesses at .05 level of significance.
The opalescence of feldspathic, IPS e.max, zirconia and Enamic ceramic specimens with 0.5 mm thickness was 1.06 ± 0.15, 3.39 ± 0.15, 1.98 ± 0.15 and 1.44 ± 0.15, respectively. By increasing the thickness to 1 mm, the opalescence of feldspathic, IPS e.max, zirconia and Enamic ceramics changed to 1.12 ± 0.15, 1.47 ± 0.15, 3.85 ± 0.15 and 2.00 ± 0.15, respectively. In all groups except for IPS e.max, the mean opalescence of 1-mm-thick specimens was higher than that of 0.5-mm-thick specimens.
Type and thickness of ceramic affect its opalescence. The opalescence of all ceramic specimens tested in this study with 0.5 and 1 mm thicknesses was lower than that of the enamel.
通过使用牙科陶瓷来创造类似牙齿的外观仍然是一个挑战。乳光效果是牙釉质的独特特性，试图通过牙科修复材料来模仿。本研究旨在评估陶瓷厚度对乳光效果的影响。
用长石陶瓷、IPS e.max、氧化锆和 Enamic 陶瓷制作 24 个直径为 10mm、厚度为 0.5mm 和 1mm 的圆盘（n = 12）。通过测量透射和反射光谱之间的黄-蓝轴（CIE ∆b*）和红-绿轴（CIE ∆a*）的差异来计算陶瓷样本的乳光效果。采用单因素方差分析比较不同厚度的不同陶瓷样本的乳光效果，显著性水平为 0.05。
厚度为 0.5mm 的长石、IPS e.max、氧化锆和 Enamic 陶瓷样本的乳光效果分别为 1.06 ± 0.15、3.39 ± 0.15、1.98 ± 0.15 和 1.44 ± 0.15。厚度增加到 1mm 时，长石、IPS e.max、氧化锆和 Enamic 陶瓷的乳光效果分别变为 1.12 ± 0.15、1.47 ± 0.15、3.85 ± 0.15 和 2.00 ± 0.15。除 IPS e.max 外，所有组中 1mm 厚样本的平均乳光效果均高于 0.5mm 厚样本。
陶瓷的类型和厚度会影响其乳光效果。本研究中测试的所有陶瓷样本（厚度为 0.5mm 和 1mm）的乳光效果均低于牙釉质。
