Kiat-Amnuay Sudarat, Lemon James C, Powers John M
Assistant Professor, Department of Restorative Dentistry and Biomaterials, The University of Texas, Houston Health Science Center, Dental Branch, Houston, TX 77030, USA.
J Prosthodont. 2002 Jun;11(2):109-16.
This study was designed to determine the effect of opacifiers used at different ratios on the color stability of pigmented A-2186 silicone maxillofacial elastomers and to evaluate the color spectrophotometrically before and after artificial aging.
Sixty experimental groups of elastomers were made using various concentrations (5%, 10%, and 15%) of 4 opacifiers (Georgia kaolin powder neutral, kaolin powder calcined, Artskin white, and dry pigment titanium white) with 1 of 5 dry earth cosmetic pigment groups (no pigment [control], red, yellow ochre, burnt sienna, and a mixture of all pigments). Five specimens of each elastomer were tested, for a total of 300 specimens. All specimens were placed in an aging chamber and artificially aged by exposure to light, water spray, fluctuating temperatures, and humidity. CIE Lab* values were measured by spectrophotometer. The color differences (Delta E*) at various exposure energies (150, 300, and 450 kJ/m(2)) were subjected to 4-way analysis of variance with repeated measures (super ANOVA). Mean values were compared with Tukey-Kramer intervals calculated at the 0.05 significance level.
The trained human eye can detect color changes (Delta E*) greater than 1.0. Adding all pigments to any of the kaolin groups did not protect silicone A-2186 from color degradation over time. Mixing red pigment in all groups at all times drastically increased DeltaE* values ranging from 0.1 to 1.3 up to 16.6 to 49.6. Yellow ochre had an effect only with 10% and 15% concentrations of kaolin powder calcined, increasing the value of Delta E* to greater than 1.0. Burnt sienna had an effect only with a 15% concentration of kaolin powder calcined, increasing the value of Delta E* at 300 and 450 kJ/m(2) to greater than 11.0. At the 5% concentration, kaolin powder calcined had the smallest color changes, followed by, in order, dry pigment titanium white, Artskin white, and Georgia kaolin. At the 10% concentration, Artskin white had the smallest color changes, followed by, in order, dry pigment titanium white, kaolin powder calcined, and Georgia kaolin. At the 15% concentration, Artskin white again had the smallest color changes, followed by, in order, dry pigment titanium white, Georgia kaolin, and the kaolin powder calcined. The smallest color changes in each kaolin group were at the 10% concentration for Artskin white, dry pigment titanium white, and kaolin powder calcined and at the 5% concentration for Georgia kaolin.
Mixing dry earth cosmetic pigments with opacifiers did not protect silicone A-2186 from color degradation over time, especially in the case of red pigment. The group in which pigments were mixed with 10% Artskin white had the smallest color changes over time, followed by, in order, the groups in which pigments were mixed with 10% dry pigment titanium white, 10% kaolin powder calcined, and 5% Georgia kaolin. Red pigment had a significant effect on all opacifiers, especially Georgia kaolin and kaolin powder calcined. Yellow ochre and burnt sienna had an effect only on 15% kaolin powder calcined. Among all the pigment groups tested, yellow ochre remained the most color stable over time.
本研究旨在确定不同比例使用的遮光剂对色素沉着的A - 2186硅酮颌面弹性体颜色稳定性的影响，并在人工老化前后用分光光度法评估颜色。
使用4种遮光剂（佐治亚高岭土粉中性、煅烧高岭土粉、Artskin白色和干颜料钛白）的不同浓度（5%、10%和15%）与5种干土化妆品色素组（无色素[对照]、红色、赭石黄、焦赭石以及所有色素的混合物）中的1种制备60个弹性体实验组。每种弹性体测试5个样本，共300个样本。所有样本置于老化箱中，通过暴露于光照、喷水、温度波动和湿度进行人工老化。用分光光度计测量CIE Lab值。对不同暴露能量（150、300和450 kJ/m²）下的颜色差异（ΔE）进行重复测量的四因素方差分析（超级方差分析）。均值与在0.05显著性水平计算的Tukey - Kramer区间进行比较。
经过训练的人眼能够检测到大于1.0的颜色变化（ΔE*）。向任何高岭土组中添加所有色素并不能防止硅酮A - 2186随时间发生颜色降解。在所有组中始终混入红色素会使ΔE值从0.1至1.3急剧增加到16.6至49.6。赭石黄仅在10%和15%浓度的煅烧高岭土粉时产生影响，使ΔE值增加到大于1.。焦赭石仅在15%浓度的煅烧高岭土粉时产生影响，在300和450 kJ/m²时使ΔE*值增加到大于11.0。在5%浓度时，煅烧高岭土粉的颜色变化最小，其次依次是干颜料钛白、Artskin白色和佐治亚高岭土。在10%浓度时，Artskin白色的颜色变化最小，其次依次是干颜料钛白、煅烧高岭土粉和佐治亚高岭土。在15%浓度时，Artskin白色再次具有最小的颜色变化，其次依次是干颜料钛白、佐治亚高岭土和煅烧高岭土粉。每个高岭土组中最小的颜色变化在10%浓度的Artskin白色、干颜料钛白和煅烧高岭土粉以及5%浓度的佐治亚高岭土时出现。
将干土化妆品色素与遮光剂混合并不能防止硅酮A - 2186随时间发生颜色降解，尤其是在红色素的情况下。色素与10% Artskin白色混合的组随时间的颜色变化最小，其次依次是色素与10%干颜料钛白、10%煅烧高岭土粉和5%佐治亚高岭土混合的组。红色素对所有遮光剂都有显著影响，尤其是佐治亚高岭土和煅烧高岭土粉。赭石黄和焦赭石仅对15%的煅烧高岭土粉有影响。在所有测试的色素组中，赭石黄随时间的颜色稳定性仍然最高。
