Rerhrhaye Wiam, Bahije Loubna, El Mabrouk Khalil, Zaoui Fatima, Marzouk Nadia
Équipe de biotechnologie et matériaux du milieu buccal, faculté de médecine dentaire de Rabat, université Mohammed V, Souissi, Morocco.
Équipe de biotechnologie et matériaux du milieu buccal, faculté de médecine dentaire de Rabat, université Mohammed V, Souissi, Morocco.
Int Orthod. 2014 Sep;12(3):271-80. doi: 10.1016/j.ortho.2014.06.006. Epub 2014 Aug 13.
Appropriate characterization studies are needed to demonstrate the mechanical and biological effects of interaction between archwires and the oral environment. The aim of this study was to investigate, in vitro, the impact of this acidic and fluoridated environment on the electrochemical behavior and the mechanical properties of orthodontic alloys in nickel titanium and in stainless steel (controls) for the following parameters: Young's modulus (E), elastic limit (σe) and the maximum tensile load (σm). Six samples of each archwire alloy were used to assess these parameters. An Instron universal test apparatus (model - 88512) was used for the traction tests on the wires after immersion in solutions at different concentrations of fluoride and at various pH levels. Observations were made using an electron scanning microscope (ESM) to evaluate the surface and an ICP (inductively coupled plasma) mass spectroscopy analysis was made to quantify the substances released into the immersion solution. For the NiTi archwires, immersion in the fluoridated and acidic medium showed a statistically significant reduction of the Young's modulus (E), the elastic limit (σe) and the maximum tensile load (σm). Similarly, a higher level of released nickel proportionate to the increase in the fluoride concentration and acidity was observed in the immersion solutions. ESM observations revealed the status of the surface of the different alloys and the presence of corrosive pitting.
需要进行适当的表征研究，以证明弓丝与口腔环境之间相互作用的力学和生物学效应。本研究的目的是在体外研究这种酸性和含氟环境对镍钛合金和不锈钢（对照）正畸合金的电化学行为和力学性能的影响，涉及以下参数：杨氏模量（E）、弹性极限（σe）和最大拉伸载荷（σm）。每种弓丝合金使用六个样本评估这些参数。将弓丝浸入不同氟浓度和不同pH值的溶液后，使用Instron万能试验机（型号-88512）对弓丝进行拉伸试验。使用电子扫描显微镜（ESM）进行观察以评估表面，并进行电感耦合等离子体质谱（ICP）分析以量化释放到浸泡溶液中的物质。对于镍钛弓丝，浸入含氟和酸性介质中显示杨氏模量（E）、弹性极限（σe）和最大拉伸载荷（σm）有统计学显著降低。同样，在浸泡溶液中观察到，释放的镍含量随着氟浓度和酸度的增加而升高。ESM观察揭示了不同合金表面的状况以及腐蚀点蚀的存在。
