Shukla Priti, Kapoor Sudhir, Jaiswal Raj Kumar, Sharma Vipul Kumar, Shashtri Dipti, Bhagchandani Jitendra
Department of Dentistry, All India Institute of Medical Sciences, Raebareli, Uttar Pradesh, India.
Department of Orthodontics and Dentofacial Orthopaedics, Sardar Patel Post Graduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India.
J Orthod Sci. 2024 Sep 17;13:27. doi: 10.4103/jos.jos_200_23. eCollection 2024.
Repeated clinical use of arch wires requires sterilization and may result in alteration of the properties of the wires as they get subjected to corrosion and cold working. Therefore, the present study aimed to assess the effects of different clinical recycling methods on the load-deflection properties of super-elastic and thermal nickel-titanium orthodontic arch wires.
A total of 50 0.014" round nickel-titanium orthodontic wires [Group I: super-elastic nickel-titanium (n = 25) and Group II: thermal nickel-titanium wires (n = 25)] were tested for changes in their load deflection properties after three different recycling methods, that is, dry heat sterilization, autoclave, and cold sterilization. For each group, five wires as received from the manufacturer were taken as control (T0), and the rest of the 20 wires were placed intra-orally for a duration of one cycle of clinical use (T1). Five wires out of these were subjected to 3-point bending tests, and the rest of the wires were subjected to different recycling methods. Load deflection properties of recycled wires were measured with an Instron universal testing machine. The results were tabulated, and the data were analyzed by analysis of variance (ANOVA) with the Tukey test.
Statistically, no significant difference was found in the super-elastic group between samples recycled by dry heat, autoclave, and cold sterilization when compared with as-received super-elastic NiTi up to 2.5 mm of deflection. A highly significant difference was found between as-received thermal NiTi group (83.51 ± 6.49 N/mm) and samples recycled by dry heat (53.73 ± 4.72 N/mm), autoclave (45.38 ± 4.37 N/mm), and cold sterilization (48.44 ± 3.12 N/mm) at 0.5 mm of deflection.
Among thermal NiTi, any of the sterilization methods could opt at all deflections. For super-elastic NiTi, at higher deflections or in cases of crowding of more than 2.5 mm, cold sterilization should be the method of choice, whereas any sterilization method can be used at deflections less than 2.5 mm.
正畸弓丝的反复临床使用需要进行消毒，并且当弓丝受到腐蚀和冷加工时，可能会导致其性能发生改变。因此，本研究旨在评估不同临床再利用方法对超弹性和热激活镍钛正畸弓丝载荷-挠度性能的影响。
总共50根0.014英寸的圆形镍钛正畸弓丝[第一组：超弹性镍钛弓丝（n = 25）和第二组：热激活镍钛弓丝（n = 25）]在经过三种不同的再利用方法（即干热消毒、高压蒸汽灭菌和冷消毒）后，测试其载荷-挠度性能的变化。对于每组，将从制造商处收到的5根弓丝作为对照（T0），其余20根弓丝放置在口腔内进行一个临床使用周期（T1）。其中5根弓丝进行三点弯曲试验，其余弓丝进行不同的再利用方法处理。使用英斯特朗万能材料试验机测量再利用弓丝的载荷-挠度性能。结果列表，并通过方差分析（ANOVA）和Tukey检验对数据进行分析。
从统计学角度来看，在超弹性组中，与未处理的超弹性镍钛弓丝相比，在挠度达到2.5 mm之前，通过干热消毒、高压蒸汽灭菌和冷消毒再利用的样本之间没有显著差异。在挠度为0.5 mm时，未处理的热激活镍钛弓丝组（83.51±6.49 N/mm）与通过干热消毒（53.73±4.72 N/mm）、高压蒸汽灭菌（45.38±4.37 N/mm）和冷消毒（48.44±3.12 N/mm）再利用的样本之间存在高度显著差异。
对于热激活镍钛弓丝，在所有挠度下任何一种消毒方法都可以选择。对于超弹性镍钛弓丝，在较高挠度或拥挤程度超过2.5 mm的情况下，冷消毒应作为首选方法，而在挠度小于2.5 mm时，可以使用任何消毒方法。
