Khaleghi Amin, Ahmadvand Atefe, Sadeghian Saeid
Department of Orthodontics, Research Committee, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Department of Orthodontics, Dental Research Center, Dental Research Institute, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Dent Res J (Isfahan). 2021 May 24;18:31. eCollection 2021.
This study aimed to assess the effect of citric acid, as a weak acid commonly used in food industry, on elastomeric chain force decay.
In this , experimental study, sixty elastomeric chains from two commercial brands of American Orthodontics and Ortho Technology ( = 30) were cut into five-piece segments. Elastomeric chains of each brand were randomly divided into two groups of control (artificial saliva) and citric acid. All elastomeric chains were incubated in artificial saliva at 37°C. Experimental samples were immersed in 10 mL of citric acid for 90 s daily and were then transferred back to the artificial saliva. The elastomeric chain force was measured at baseline (before the experiment), 1 day, 1 week, 2 weeks, and 3 weeks using an electromechanical universal testing machine. Data were analyzed using -test, Kruskal-Wallis test, and Mann-Whitney U-test at 0.05 level of significance.
The elastomeric chain force gradually degraded over time. The difference in this respect was not significant at 2 and 3 weeks in any group ( > 0.05). On initiation of the experiment, the force in the citric acid group experienced a greater decay than that in the control group; the difference between the citric acid and control groups in both the brands was significant at all time points until the end of the 3 week ( < 0.05). The difference between the American Orthodontics and Ortho Technology brands in the control and citric acid groups was significant at all time points ( < 0.001).
Elastomeric chains in both the citric acid and artificial saliva groups experienced force decay over time. Force decay was greater in the citric acid group. Thus, citric acid can effectively decrease the elastomeric chain force. The Ortho Technology chain force was higher than that of American Orthodontics in both the groups at all time points.
本研究旨在评估柠檬酸（一种食品工业中常用的弱酸）对弹性链力衰减的影响。
在本实验研究中，将来自美国正畸公司和正畸技术公司两个商业品牌的60条弹性链（每个品牌30条）切成五段。每个品牌的弹性链随机分为对照组（人工唾液）和柠檬酸组。所有弹性链均在37℃的人工唾液中孵育。实验样本每天浸入10 mL柠檬酸中90秒，然后再转移回人工唾液中。使用机电式万能试验机在基线（实验前）、1天、1周、2周和3周时测量弹性链力。数据采用t检验、Kruskal-Wallis检验和Mann-Whitney U检验进行分析，显著性水平为0.05。
弹性链力随时间逐渐下降。在任何一组中，2周和3周时在这方面的差异均无统计学意义（P>0.05）。在实验开始时，柠檬酸组的力衰减比对照组更大；在3周结束前的所有时间点，两个品牌的柠檬酸组和对照组之间的差异均有统计学意义（P<0.05）。对照组和柠檬酸组中，美国正畸公司和正畸技术公司品牌在所有时间点的差异均有统计学意义（P<0.001）。
柠檬酸组和人工唾液组的弹性链力均随时间衰减。柠檬酸组的力衰减更大。因此，柠檬酸可有效降低弹性链力。在所有时间点，两组中正畸技术公司的链力均高于美国正畸公司。
