镍钛弹簧在口腔正畸中的应用

螺旋弹簧包括压缩螺旋弹簧、拉伸螺旋弹簧和扭转螺旋弹簧。螺旋弹簧于1931年引入口腔正畸用于移动牙齿．主要应用的是拉伸螺旋弹簧和压缩螺旋弹簧。早期制作螺旋弹簧的材料是不锈钢丝．后来出现了钴铬镍合金螺旋弹簧。但这些弹簧加载后产生的初始应力值较大．卸载过程应力衰减快．不利于牙齿生理移动。因此．正畸学者一直在寻找一种能产生温和矫治力的螺旋弹簧。镍钛螺旋弹簧于上世纪80年代末出现．目前正广泛应用于口腔正畸临床。

镍钛螺旋弹簧在固定正畸中的临床应用

作者通过检测镍钛螺旋弹簧的弹力性能和其在Ｅｄｇｅｗｉｓｅ矫正技术中拉尖牙远中移动的临床应用研究，认为：只要注意掌握镍钛螺旋弹簧的弹性特点及力的大小，其可产生一种轻柔、恒定持续、安全的正畸力。

镍钛螺旋弹簧推尖牙远中移动的临床研究

目的 :探讨镍钛螺旋弹簧推上颌尖牙远移后支抗牙及被移动牙的变化情况。方法 :选择 2 0例经拔除4 44 4| 采用方丝弓技术矫治的恒牙期患者 ,行镍钛螺旋弹簧推上尖牙远中移动 ,力 15 0克。推尖牙前后照尖牙牙片及X线头颅侧位片进行定量分析比较 ,记录尖牙远移到位时间。结果 :6平均向近中移动 0 9mm(P <0 .0 1) ,而 6长轴倾斜度基本无变化。上中切牙平均前移 1 2 7mm ,上切牙突度平均增加 3 82°(P <0 .0 0 1) ,表现为支抗前牙有唇向倾斜移动。3 3⊥ 平均远移到位时间为 3 87± 1 18月 ,未发现尖牙牙根吸收。结论 :镍钛螺旋弹簧推尖牙向远中适合面型不突或前突不严重者 。

镍钛开大螺旋弹簧在牙列拥挤局部间隙开辟中的临床应用

目的评价镍钛开大螺旋弹簧在局部间隙开辟中的临床效果。方法随机选择恒牙牙列拥挤病例14例,年龄12～28岁,在拥挤区放置镍钛开大螺旋弹簧,每2～3周复诊1次。结果所有病例在5～21周开辟出足够间隙,牙列拥挤解除。结论镍钛螺旋弹簧在局部间隙开辟中提供了一种有效而简单的方法。

镍钛螺旋弹簧与弹力橡皮链远中移动尖牙的比较研究

以１２例年龄１２岁～２５岁的ＡｎｇｌｅⅡ＇类和ＡｎｇｌｅⅠ类拥挤的患者为研究对象，拔除第一双尖牙，排齐整平牙列后，在上颌的右侧放置镍钛螺旋弹簧，在左侧放置弹力橡皮链，两侧用１８０ｇ力同时远中牵引尖牙，每四周复诊一次，平均牵引４个月，并对牵引前后阶段模型进行测量分析。发现右侧尖牙远中移动距离平均为３．８６ｍｍ，左侧为２．９４ｍｍ。而右侧牙弓长度缩短１．１２ｍｍ，左侧为２．７８ｍｍ。患者镍钛螺旋弹簧侧感到不适发生的频率及牙龈炎率大于弹力橡皮链侧。

片段弓与镍钛螺旋弹簧拉尖牙向远中的临床应用对比研究

目的对比片段弓和镍钛螺旋弹簧在口腔正畸治疗拉尖牙向远中的应用.方法选择36例牙列拥挤,双侧对称拔除第一双尖牙且需将尖牙拉向远中的患者,用方丝弓矫正技术,随机选择18例为实验组使用片段弓,另外18例为对照组使用镍钛螺旋弹簧,分别拉下颌尖牙向远中.测量尖牙向远中移动的距离以及磨牙向近中倾斜的角度.结果实验组牙齿移动的速度为(1.285±0.084)mm/月,快于对照组(0.987±0.066)mm/月,实验组磨牙近中倾斜的程度为(1.86±0.120)°小于对照组(2.49±0.140)°,两者经统计学检验差异有统计学意义(P<0.05).结论使用片段弓拉尖牙向远中在牙齿移动速度以及控制磨牙近中倾斜等方面均优于使用镍钛螺旋弹簧,建议应优先采用.

滑动杆推簧排齐前牙的运用2例

正畸排齐前牙时,使用0.5 mm直径不锈钢丝弯制滑动杆,在拥挤前牙两侧放置镍钛推簧,在交互力系下推开间隙、维持间隙的同时排齐前牙,用于治疗2例前牙轻中度拥挤患者,成功矫正了前牙拥挤、中线不齐等畸形。

Analytical Solutions of the Equations One Mechanical Thermal Model of a Helical Spring NiTi for Use in Heat Engine

Shape memory effect is capability of certain materials to recover its original shape after an apparently permanent deformation. The NiTi alloy of the composition is approximately equiatomic and it is the materials that exhibit the best characteristics for application of these properties, especially in the biomedical area, because of their excellent biocompatibility as： in the manufacture of medical and dental instruments, orthodontic wires, orthopedic materials, guide wires, stents, filters and components to realize the less invasive surgeries. In other areas, they are used for confections of electronic keys, spectacle frames, application in controllers, junction of pipes and electronic connectors among others. New research topics involving the application of these alloys super-elasticity are also known as pseudo elasticity. This event has an isothermal nature and involves the storage of potential energy in the shape memory effect and super-elasticity. In this context, this work falls within the scope of use of the technologies being an example of the work undertaken, in the course Graduate of Federal University of Pernambuco in skills in these technologies. It will present the results of a heat engine which engine element is a helical spring made of a NiTi alloy equiatomic with memory effect reversibly. The spring is triggered by a hot source （- 373.15 K） and a cold source （273.15 K）. The machine is capable of producing a reciprocating oscillating between the two sources. Heat equations and the equations that describe the dynamic behavior of the spring were developed. Through the development of dynamic equations, it can determine the minimum mass for the motion of the machine, as well as the instantaneous and average power and overall efficiency. You can check the functionality of the machine by way of the inclination angle of the propeller and the coefficient of static friction. Among the main results, it was observed that the overall performance of the machine compared to the machines of this category showed the feasibility of the project.

钛及钛合金特性及其在口腔正畸临床中的应用

本文阐述了以镍钛丝、β钛丝、镍钛推簧、钛钉、钛板为代表的钛及钛合金材料的性能特征、国内外研究开发现状、应用沿革以及其目前在口腔正畸临床治疗中的应用情况和存在的问题。