Doctoral student, Academic Centre for Reconstructive Science, King's College London, Guy's Hospital, London, United Kingdom.
Visiting Professor, School of Oral and Dental Sciences, University of Bristol, Bristol, United Kingdom.
J Prosthet Dent. 2018 Sep;120(3):476-482. doi: 10.1016/j.prosdent.2017.11.016. Epub 2018 Apr 5.
The color degradation of maxillofacial prostheses in clinical service requires their frequent renewal. How different materials compare is unclear.
The purpose of this in vitro study was to investigate the color stability of a nonpigmented and pigmented maxillofacial silicone when stored in darkness and exposed to accelerated aging in a weathering chamber and natural outdoor weathering.
M511 elastomer was colored with Spectromatch Pro colorants, stored in darkness, and exposed to accelerated aging and natural outdoor weathering for 1500 hours. Test groups included nonpigmented specimens (n=18), individually pigmented specimens (n=90), and Caucasian skin tone-colored specimens (n=18). The CIELab values of the test specimens were measured using the CM-2600d spectrophotometer (Konica Minolta Sensing) at base line (0 hours) and then every 100 hours up to 1500 hours of aging. Color changes (ΔE) were calculated based on the recorded CIELab values. All data were analyzed by using linear mixed models and the Šídák multiple comparison of means test (α=.05).
A significant effect of time was found on the ΔE of all test specimens in all environments (P=.001). All pigmented M511 specimens demonstrated good color stability with maximum ΔE below the acceptability threshold of 2 ΔE when stored in darkness and exposed to outdoor weathering. However, nonpigmented specimens crossed this acceptability threshold when exposed to outdoor weathering with maximum ΔE values of 3.65. The greatest color changes were observed for all specimens when exposed to accelerated aging and most exceeded the acceptability threshold. Nonpigmented (ΔE, 4.86) and Indian yellow (ΔE, 5.20) demonstrated the highest color changes after 1500 hours.
All environments resulted in visible color changes of nonpigmented and pigmented M511 elastomer. The lowest ΔE values were observed for specimens stored in darkness and the greatest for specimens exposed to accelerated aging. The organic pigment Logwood maroon demonstrated the best color stability with maximum ΔE values below the perceptibility threshold (PT) of 1 ΔE.
临床使用中的颌面修复体颜色退化需要频繁更换。不同材料的比较情况尚不清楚。
本体外研究的目的是调查非着色和着色颌面硅橡胶在黑暗中储存以及在风化室和自然户外风化中暴露于加速老化时的颜色稳定性。
将 M511 弹性体用 Spectromatch Pro 着色剂着色，存放在黑暗中，并暴露于加速老化和自然户外风化 1500 小时。实验组包括非着色标本（n=18）、单独着色标本（n=90）和高加索肤色着色标本（n=18）。使用 CM-2600d 分光光度计（柯尼卡美能达传感）在基线（0 小时）时测量测试标本的 CIELab 值，然后每 100 小时测量一次，直至老化 1500 小时。基于记录的 CIELab 值计算颜色变化（ΔE）。使用线性混合模型和 Šídák 均值多重比较检验（α=.05）对所有数据进行分析。
在所有环境中，时间对所有测试标本的 ΔE 均有显著影响（P=.001）。所有着色的 M511 标本在黑暗中储存和暴露于户外风化时均表现出良好的颜色稳定性，最大 ΔE 低于可接受阈值 2 ΔE。然而，非着色标本在暴露于户外风化时超过了这一可接受阈值，最大 ΔE 值为 3.65。所有标本在暴露于加速老化时观察到最大的颜色变化，大多数标本超过了可接受阈值。非着色标本（ΔE，4.86）和印度黄（ΔE，5.20）在 1500 小时后表现出最高的颜色变化。
所有环境都会导致非着色和着色 M511 弹性体的可见颜色变化。在黑暗中储存的标本的 ΔE 值最低，而暴露于加速老化的标本的 ΔE 值最高。有机颜料 Logwood maroon 表现出最佳的颜色稳定性，最大 ΔE 值低于可察觉阈值（PT）1 ΔE。
