Fernandes Alline Birra Nolasco, Ruellas Antônio Carlos Oliveira, Araújo Marcus Vinicius Almeida, Sant'Anna Eduardo Franzotti, Elias Carlos Nelson
Department of Orthodontics, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
J Orthod. 2014 Jun;41(2):147-51. doi: 10.1179/1465313313Y.0000000083. Epub 2014 Feb 12.
The aim of this study was to evaluate colour alteration of transparent elastic ligatures submitted to exogenous pigmentation.
Forty test specimens were divided into eight groups corresponding to one commercial brand with five test specimens in each group. The test specimens were immersed into coffee and black tea solutions with the purpose of assessing colour alteration using a portable digital spectrophotometer (Vita Easyshade Compact). The surfaces of the ligatures under scanning electron microscope (SEM) at ×30, ×150 and ×20,000 magnification were evaluated with the purpose of observing the differences in porosity of the ligatures. The Kolmogorov-Smirnov test for normality was applied followed by the one-way analysis of variance (one-way ANOVA) and the level of significance adopted was 95%.
All the groups showed modified initial colour that was perceptible to the human eye. The brand that showed greater colour alteration, in comparison with its initial colour, was the American® pearl elastic ligature and the ligatures that presented the smallest colour variation were the Ortho-Organizer®. The surface evaluations of the ligatures showed differences with regard to the topography evidencing more porosity in the ligatures that showed greater staining.
The group that changed colour significantly was the one that presented the highest porosity, and the brand that was the least altered was the one that showed the lowest porosity.
本研究的目的是评估经受外源性色素沉着的透明弹性结扎丝的颜色变化。
40个测试样本被分为8组，对应一个商业品牌，每组有5个测试样本。将测试样本浸入咖啡和红茶溶液中，目的是使用便携式数字分光光度计（Vita Easyshade Compact）评估颜色变化。在扫描电子显微镜（SEM）下以×30、×150和×20,000的放大倍数观察结扎丝的表面，目的是观察结扎丝孔隙率的差异。应用柯尔莫哥洛夫-斯米尔诺夫正态性检验，随后进行单因素方差分析（单向方差分析），采用的显著性水平为95%。
所有组均显示出肉眼可察觉的初始颜色变化。与初始颜色相比，颜色变化较大的品牌是American®珍珠弹性结扎丝，颜色变化最小的结扎丝是Ortho-Organizer®。结扎丝的表面评估显示，在地形方面存在差异，显示出染色较多的结扎丝孔隙率更高。
颜色变化显著的组是孔隙率最高的组，变化最小的品牌是孔隙率最低的品牌。
