Professor, Department of Dental Materials and Prosthodontics, Sao Paulo State University (UNESP), School of Dentistry, Aracatuba, Sao Paulo, Brazil.
Postgraduate student, Department of Dental Materials and Prosthodontics, Sao Paulo State University (UNESP), School of Dentistry, Aracatuba, Sao Paulo, Brazil.
J Prosthet Dent. 2017 Sep;118(3):430-436. doi: 10.1016/j.prosdent.2016.10.023. Epub 2017 Feb 20.
The stability of the optical characteristics of dental ceramics is essential. Degradation of these materials resulting from pH or temperature alterations in the oral cavity can lead to treatment failure.
The purpose of this in vitro study was to evaluate the color change (ΔE), the L* coordinate, the translucency parameter, and the contrast ratio of lithium disilicate ceramic exposed to commonly used and potentially colorant solutions.
Fifty lithium disilicate specimens were prepared and divided into 5 groups according to the immersion solution (artificial saliva, orange juice, cola, coffee, and red wine). Immersions in acidic beverages were alternated in a thermocycler with artificial saliva. The control group was immersed in artificial saliva at 37°C throughout the immersion period. After 168 hours of immersion, the color parameters were assessed with a spectrophotometer and calculated using the because system on 2 backgrounds (black and white) and in 2 time periods, before thermocycling and after thermocycling. Data were submitted to analysis of variance followed by the Tukey honest significant difference test (α=.05).
Greater color change (ΔE) and lower L* coordinate values were observed after immersion in orange juice and cola. Regarding the translucency parameter and contrast ratio, the immersion in coffee resulted in greater opacity and lower translucency of the material.
Alterations in the color stainability, the L* coordinate values, the translucency parameter, and the contrast ratio of the lithium disilicate ceramic were observed, according to the acidic solutions tested.
牙科陶瓷光学特性的稳定性至关重要。这些材料在口腔中因 pH 值或温度变化而降解可能导致治疗失败。
本体外研究的目的是评估暴露于常用和潜在着色剂溶液的锂硅玻璃陶瓷的颜色变化（ΔE）、L*坐标、半透明度参数和对比度比值。
制备了 50 个锂硅玻璃陶瓷样本，并根据浸泡溶液（人工唾液、橙汁、可乐、咖啡和红酒）将其分为 5 组。在热循环器中，将酸性饮料的浸泡交替进行，用人工唾液浸泡。对照组在整个浸泡期间都在 37°C 的人工唾液中浸泡。浸泡 168 小时后，使用分光光度计评估颜色参数，并使用 because 系统在 2 个背景（黑色和白色）和 2 个时间段（热循环之前和热循环之后）下计算。数据采用方差分析，然后采用 Tukey 诚实显著差异检验（α=.05）。
在橙汁和可乐中浸泡后，观察到更大的颜色变化（ΔE）和更低的 L*坐标值。关于半透明度参数和对比度比值，咖啡浸泡导致材料的不透明度增加和半透明度降低。
根据测试的酸性溶液，观察到锂硅玻璃陶瓷的颜色染色性、L*坐标值、半透明度参数和对比度比值发生了变化。
