Akyalcin Sercan, Rykiss Jared, Rody Wellington J, Wiltshire William A
University of Texas School of Dentistry at Houston, Houston, TX, USA.
J Orthod. 2012 Sep;39(3):170-5. doi: 10.1179/1465312512Z.00000000024.
To analyse the staining properties of clear orthodontic brackets using a digital analysis.
In vitro, laboratory study
A total of 500 tooth-coloured brackets from 10 brands (five ceramic and five plastic) were investigated. The cumulative discolouring effect of staining agents (tea, coffee, curry and red wine) were analysed at two consumption levels: light and heavy, based on a 6-month period of exposure. Study group brackets were immersed in the agents consecutively at 37°C. The control group was only exposed to artificial saliva. Samples were analysed digitally to obtain L*, a* and b* (lightness, red-green and yellow-blue) colour readings. Using these values, total colour change (ΔE*) at each level was also calculated. Three-way analysis of variance (ANOVA) test was used for statistical comparisons.
L* and b* colour parameters showed significant differences (P<0·001) between different bracket groups, consumption levels and the type of exposure. However, the a* value only differed between bracket groups (P<0·001). According to the ΔE* values, ceramic brackets had less colour change than plastic brackets at the end of phase 1 for both the study and control groups. However, as consumption time increased, the rate of colour change decreased for the plastic brackets. In general, ceramic brackets demonstrated much more resistance to staining agents than plastic brackets.
Both plastic and ceramic brackets showed changes in colour when exposed to heavy consumption of staining agents, with plastic brackets being the most affected.
使用数字分析方法分析透明正畸托槽的染色特性。
体外实验室研究
对来自10个品牌（5种陶瓷托槽和5种塑料托槽）的共500个牙齿颜色的托槽进行了研究。基于6个月的暴露期，分析了染色剂（茶、咖啡、咖喱和红酒）在轻度和重度两种消费水平下的累积变色效果。研究组托槽在37°C下连续浸泡在这些染色剂中。对照组仅暴露于人工唾液。对样本进行数字分析以获得L*、a和b（明度、红绿色度和黄蓝色度）颜色读数。利用这些值，还计算了每个水平下的总颜色变化（ΔE*）。采用三因素方差分析（ANOVA）检验进行统计比较。
不同托槽组、消费水平和暴露类型之间，L和b颜色参数显示出显著差异（P<0.001）。然而，a值仅在托槽组之间存在差异（P<0.001）。根据ΔE值，在研究组和对照组的第1阶段结束时，陶瓷托槽的颜色变化比塑料托槽少。然而，随着消费时间的增加，塑料托槽的颜色变化速率降低。总体而言，陶瓷托槽比塑料托槽对染色剂的耐受性要强得多。
当暴露于大量染色剂时，塑料和陶瓷托槽都会出现颜色变化，其中塑料托槽受影响最大。
