在重复发烧下,压制脱酸盐陶的色彩稳定性通过不同的方法进行评估
The International journal of prosthodontics
|March 13, 2024
概括
重复的燃烧周期会导致二陶的颜色发生显著变化,但这些在临床上是可以接受的. 不同的测量仪器也显示了色彩分析的显著差异.
科学领域:
- 牙科材料科学 牙科材料科学
- 陶修复 陶修复 陶修复
- 测色仪的颜色测量方法
背景情况:
- 二酸陶广泛用于牙科修复.
- 重复的燃烧周期可能会改变陶材料的颜色稳定性.
- 准确的颜色评估对于实现牙科美学结果至关重要.
研究的目的:
- 量化和比较经过多次燃烧周期后压制的脱酸陶样品的颜色差异.
- 为了评估不同仪器测量的颜色差异 (CIEDE2000) 之间的相关性:X-Rite Color i5光谱仪,VITA EasyShade Advance 4.0,以及Adobe Photoshop.
主要方法:
- 三十六个脱酸标本 (单色和多色) 经历了七次重复的燃烧周期.
- 颜色分析 (CIE L*a*b*) 在第一,第二,第三,第五和第七次燃烧周期后进行.
- 使用光谱仪,数字阴影指南和图像分析软件的数据计算了颜色差异 (CIE DE*2000).
主要成果:
- 多次燃烧周期导致二酸盐标本的统计学上显著的颜色差异 (ΔE*00) (P < .001).
- 在不同阴影组和测量仪器之间观察到颜色评估的显著差异 (P < .05).
- 阴影,点火周期和仪器之间的互动效应也显示出统计学意义 (P < .05).
结论:
- 压二酸盐陶在重复燃烧周期后显示出显著的颜色变化.
- 尽管存在统计学上显著的差异,但观察到的颜色变化被认为是临床上可接受的.
- 对于CIE L*a*b*值的测量仪器之间存在差异,但仍在人类可感知的容忍范围内.
相关概念视频
02:39Indicators
Certain organic substances change color in dilute solution when the hydronium ion concentration reaches a particular value. For example, phenolphthalein is a colorless substance in any aqueous solution with a hydronium ion concentration greater than 5.0 × 10−9 M (pH < 8.3). In more basic solutions where the hydronium ion concentration is less than 5.0 × 10−9 M (pH > 8.3), it is red or pink. Substances such as phenolphthalein, which can be used to determine the pH of a solution, are called...
03:46Qualitative Analysis
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...
01:18Titration of Polyprotic Base with a Strong Acid
The titration of a polyprotic base such as sodium carbonate with a strong acid such as hydrochloric acid results in two equivalence points on the titration curve. At the first equivalence point, the carbonate ions in the base are completely converted to bicarbonate ions. The second equivalence point corresponds to the complete conversion of bicarbonate ions to carbonic acid, which dissociates into carbon dioxide and water. The region before the first equivalence point corresponds to the...
01:18Effects of EDTA on End-Point Detection Methods
Different methods, such as visual observance of metal-ion indicators, spectroscopic techniques, and potentiometric methods, can determine the endpoint of an EDTA titration.
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA...
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a result, EDTA...
01:19Precipitation Titration: Endpoint Detection Methods
In argentometric precipitation titrations, endpoints can be detected visually by the Mohr, Volhard, and Fajans methods. In the Mohr method, adding a soluble chromate indicator gives an initial yellow color to the analyte solution. As the titrant is added, the first excess of silver ions forms a red silver chromate precipitate, marking the endpoint. The solution pH should be maintained at about 8 by adding solid CaCO3.
In the Volhard method, a standard excess of AgNO3 is first added to the...
In the Volhard method, a standard excess of AgNO3 is first added to the...
00:52Washing, Drying, and Ignition of Precipitates
After filtration, the precipitate is washed to remove coprecipitated impurities and any remaining mother liquor. Colloidal precipitates, such as silver chloride, are washed with an electrolyte (such as dilute nitric acid) to prevent the peptization of the precipitate. In the case of slightly soluble precipitates, the wash solution contains a common ion to reduce solubility. Lead sulfate, which is slightly soluble in water, is washed with dilute sulfuric acid. Similarly, wash solutions may be...