Blagec Tadeja, Šimunović Luka, Pili Gjumlić Sandra, Šutej Ivana, Meštrović Senka
Department of Orthodontics, School of Dental Medicine, University of Zagreb, Zagreb, Croatia.
Clinical Hospital Centre Zagreb, Zagreb, Croatia.
Saudi Dent J. 2024 Feb;36(2):308-314. doi: 10.1016/j.sdentj.2023.11.008. Epub 2023 Nov 7.
To assess the impact of pH level on force decay and color stability of orthodontic elastomeric chains (EOC) after exposure to commonly used beverages.
A total of 120 chain cuts were prepared from 2 different manufacturers (GC Orthodontics Europe GmbH, Breckerfeld, Germany, and FORESTADENT® - Bernhard Foerster GmbH, Pforzheim, Germany). According to the distance between loops, two types of chains were selected from each manufacturer: short and medium ones. Chains were immersed into 10 commonly used beverages with different pH values. After 7 days, force degradation was evaluated with the universal machine for mechanical testing (Model 4411; Instron, Canton, USA) and color change using a VITA Easyshade® digital spectrophotometer. Kruskal-Wallis with post-hoc Dunn's test for intergroup comparison and Wilcoxon rank test for intragroup comparison.
Initial force varied among EOC brands, with GC short chains having the highest force and Forestadent medium chains the lowest. The most pronounced force decay occurred within 24 h, notably affecting Forestadent short chains the most, followed by Forestadent medium, GC short, and GC medium chains. Despite a higher force drop rate over seven days, short EOCs maintained higher forces than medium EOCs. GC EOCs consistently maintained higher forces after seven days compared to Forestadent EOCs. After the immersion of EOC in different solutions for 24 h, only Evian water, Soy milk, and Coconut water did not change color. After 7 days, the greatest color change was recorded in coffee.
There is no correlation between pH value and force decay of polyurethane chains. Short chains showed more constant force delivery and greater value of remaining force in comparison to medium ones. Color stability was mostly affected by coffee, followed by matcha tea, soy milk, and apple juice.
评估pH值对正畸弹性链（EOC）在接触常用饮料后力衰减和颜色稳定性的影响。
从2个不同制造商（德国布雷克费尔德的GC正畸欧洲有限公司和德国普福尔茨海姆的FORESTADENT® - 伯恩哈德·弗尔斯特有限公司）制备了总共120段链段。根据环之间的距离，从每个制造商中选择两种类型的链：短链和中链。将链浸入10种不同pH值的常用饮料中。7天后，使用万能机械测试机（型号4411；美国康顿的英斯特朗公司）评估力的降解，并使用VITA Easyshade®数字分光光度计评估颜色变化。采用Kruskal-Wallis检验及事后Dunn检验进行组间比较，采用Wilcoxon秩和检验进行组内比较。
初始力在EOC品牌之间有所不同，GC短链的力最高，Forestadent中链的力最低。最明显的力衰减发生在24小时内，对Forestadent短链影响最大，其次是Forestadent中链、GC短链和GC中链。尽管在7天内短EOC的力下降率较高，但短EOC保持的力高于中EOC。与Forestadent EOC相比，GC EOC在7天后始终保持较高的力。将EOC浸入不同溶液24小时后，只有依云矿泉水、豆浆和椰子水没有变色。7天后，咖啡中的颜色变化最大。
聚氨酯链的pH值与力衰减之间没有相关性。与中链相比，短链显示出更稳定的力传递和更大的剩余力值。颜色稳定性主要受咖啡影响，其次是抹茶、豆浆和苹果汁。
