Influence of elastic chain in the degradation of orthodontic forces - in vitro study

AbstractIntroductionElastic chains are indispensable accessories in orthodontic treatment. Changes in their properties are of great interest to professionals in order to gain greater control over tooth movements.ObjectiveEvaluate the influence of trademark and length of the spacer chain on force degradation of elastic.Material and methodWe used the following elastic chain types: TP, Rocky Mountain (RMO) and GAC short, medium and long varieties. The elastics, which contained links corresponding to 12.5 mm, were tensioned between steel pins using Instron 4411 universal testing machine up to 25 mm. The value was recorded. After initial measurement of the force, the elastics were fixed on an acrylic resin plate and kept distended to 25 mm. They were inserted in a container with deionized water and kept in an incubator at 37º. The elastic force data was collected at time intervals of 24 hours, 48 hours, 7 days, 14 days, 21 days and 28 days. These records were subjected to an appropriate statistical test, with significance level of 5%.ResultTP elastics showed significantly higher force in all periods. RMO and GAC elastics showed similar elastic forces. Short and long TP elastics exhibited significantly higher strength than the average elastic chain. As regards GAC and RMO, short elastics showed higher than average force values, and higher values than the long type.ConclusionThe spacer chain and the brand influenced the results, reinforcing the importance of knowledge of different types of elastic.

研究背景：弹性链是正畸治疗中不可或缺的辅助器材，其性能变化始终受到正畸专业人士的广泛关注，以期实现对牙齿移动的更精准调控。
研究目的：评估分牙弹性链（spacer chain）的品牌与长度对其弹力衰减的影响。
材料与方法：本研究选用TP、Rocky Mountain（RMO）及GAC三个品牌的弹性链，各品牌均涵盖短、中、长三种规格。选取节距对应12.5mm的弹性链样品，通过Instron 4411万能试验机将其固定于钢销之间并拉伸至25mm，记录初始弹力值。初始测量完成后，将弹性链固定于丙烯酸树脂板上并维持拉伸至25mm的状态，随后将其放入盛有去离子水的容器中，置于37℃恒温培养箱内保存。分别于24小时、48小时、7天、14天、21天及28天六个时间点采集弹力数据，并采用显著性水平为5%的合适统计学方法进行数据分析。
研究结果：TP品牌弹性链在所有观测时间点的弹力均显著高于其余两个品牌；RMO与GAC品牌弹性链的弹力水平较为相近。TP品牌的短款与长款弹性链的弹力均显著高于其中款平均水平。对于GAC与RMO品牌，短款弹性链的弹力值高于平均水平，且高于长款弹性链。
结论：分牙弹性链的品牌与长度均对其弹力衰减效果存在显著影响，这凸显了全面掌握不同类型弹性链性能的重要性。