不同尺寸多曲方丝弓在不同托槽系统中局部载荷挠曲率的实验研究

目的测量并比较3种尺寸不锈钢方丝弯制的多曲方丝弓分别在2种托槽系统中不同牙位间的局部载荷挠曲率,分析多曲方丝弓的力学特性。方法分别用0.41 mm×0.56 mm、0.43 mm×0.64 mm、0.46 mm×0.64 mm型号的不锈钢方丝弯制多曲方丝弓（MEAW）弓丝中独立的“L”形曲。用电子万能材料试验机在室温下对各“L”形曲分别在上下颌不同牙位间进行加载和卸载实验,将0.41 mm×0.56 mm的“L”形曲固定于0.46 mm×0.64 mm的托槽（A托槽）中,0.43 mm×0.64 mm和0.46 mm×0.64 mm的“L”形曲固定于0.56 mm×0.71 mm的托槽（B托槽）中。各牙位间的待测弓丝分别取5个样本重复实验,测得各自的局部载荷挠曲率,数据用SPSS 11.0软件包进行统计处理。结果0.41 mm×0.56 mm的“L”形曲在A托槽与0.43 mm×0.64 mm的“L”形曲在B托槽的不同牙位间的局部载荷挠曲率相比较,除在上颌1-2、下颌1-2和2-3二者间差异有统计学意义外（P＜0.05）,在其余牙位间,差异均无统计学意义（P＞0.05）。0.41 mm×0.56 mm的“L”形曲在A托槽与0.46 mm×0.64 mm的“L”形曲在B托槽的不同牙位间的局部载荷挠曲率相比较,除在下颌6-7二者间差异无统计学意义外（P＞0.05）,在上下颌其余牙位间,二者间差异均有统计学意义（P＜0.05）。结论在B托槽系统中用0.43 mm×0.64 mm不锈钢方丝弯制的MEAW弓丝,其力学性能与在A托槽系统中用0.41 mm×0.56 mm的不锈钢方丝弯制的MEAW弓丝相似。在临床应用时,可适当增减“L”形曲的长度,以提高矫治效能。     

垂直曲对弓丝转矩性能的影响研究

目的 :定量分析不同垂直臂高度的垂直曲弓丝的抗扭刚度 ,揭示垂直曲对弓丝第三序列弯曲方向上力学性能的影响的规律 ,为临床合理精确使用转矩力提供依据。材料与方法 :选取 0 .0 2 2英寸标准方丝弓中切牙托槽、横截面尺寸 0 .0 18× 0 .0 2 5英寸不锈钢丝。随机抽取 10根方丝 ,每根方丝制作垂直臂高度分别为 3.5mm、7mm、10 .5mm、14mm的 4种垂直曲弓丝。在 5 .5mm的托槽间距下对垂直曲弓丝的 4 0个样本分别进行转矩实验。结果 :垂直臂为 3.5mm、7mm、10 .5mm、14mm的垂直曲弓丝的抗扭刚度分别为平直弓丝抗扭刚度的 92 .6 %、84 .3%、78.4 %、70 .4 %。垂直臂高度越高 ,降低抗扭刚度的效果越明显。垂直曲的垂直臂每升高lmm ,其抗扭刚度下降 0 .0 84Nmm/度。弓丝弯制造成的塑性形变使弓丝的抗扭刚度下降 2 .998Nmm/度。结论 :垂直曲的加入使弓丝的抗扭刚度降低。曲弯制造成的塑性形变段和曲弯制后保留的直线段均参与了垂直曲设计降低弓丝抗扭刚度的作用。     

排齐辅弓技术在Edgewise矫治技术第一期中的应用

Edgewise矫治技术以其高效能、速度快、精确控制牙齿移动,而被临床广泛使用.但笔者在临床工作中发现,许多前牙拥挤拔牙矫治的患者,在Edgewise矫治技术第一期整平排齐阶段,采用NiTi圆丝或多垂直曲不锈钢圆丝的弓丝设计,往往出现后牙支抗丢失,不易控制牙弓形态,易刺激口腔软组织,临床操作复杂费时.本文对58例恒牙期前牙拥挤拔牙矫治患者进行研究,平均年龄12岁.在Edgewise矫治技术第一期使用的弓丝设计以澳丝或正畸用不锈钢丝为主弓,0.41mm直径;高效能镍钛丝为前牙截段辅弓,0.36mm直径.经过应用不仅保持了牙弓应有的形态,增强了后牙支抗,而且快速排齐拥挤错位的前牙,有利于打开咬合.疗程最短4个月,最长1年2个月,平均疗程9个月,取得了满意的疗效.     

复合矫治弓丝用于正畸拔牙矫治的三维有限元研究

目的通过建立三维有限元模型分析正畸拔牙矫治时复合矫治弓丝（compositearehwire，CoAW）的力学性能，探讨CoAW的应用选优问题。方法通过螺旋CT扫描，利用SOUDWORKS2001PLUS软件重建下颌骨三维有限元模型，模拟拔除两侧第一前磨牙矫治，在ANSYS软件中建立3种镍钛圆丝（直径为0．30mm、0．36mm、0．41mm）、2种不锈钢圆丝（直径为0．36mm、0．41mm）和6种CoAW（0．30mm、0．36imm、0．41mm直径的镍钛圆丝分别连接0．36mm、0.41mm直径的不锈钢圆丝）弓丝模型，进行力学加载与计算分析。结果当CoAW中镍钛段弓丝直径逐渐加大，而不锈钢丝段弓丝直径保持不变时，牙齿所受的应力逐渐增加。当CoAW中不锈钢丝段弓丝直径逐渐增大，而镍钛段弓丝直径保持不变时，牙齿所受的应力也逐渐增加。在6种组合的CoAW中，以CoAW（0．30mm直径的镍钛圆丝连接0．36mm直径的不锈钢圆丝）对牙齿产生的应力最小。对于支抗后牙的应力大小，6种组合的CoAW与不锈钢丝比较未见明显区别。结论CoAW中镍钛段与不锈钢丝段弓丝的直径与牙齿所受的应力大小密切相关。     

人工唾液中直丝弓托槽与弓丝静摩擦力的实验研究

目的探讨人工唾液条件下,不同时间,几种直丝托槽与弓丝在后牙段的静摩擦力特点。方法在人工唾液条件下,4个时间段,测试4种直丝托槽与4种弓丝组合在后牙段的静摩擦力。结果0.46mm不锈钢圆丝的静摩擦力最小,0.48mm×0.64mm不锈钢方丝的静摩擦力最大。弓丝、托槽组合在人工唾液条件下作用15d静摩擦力最大、30d静摩擦力最小。结论0.46mm不锈钢圆丝的静摩擦力最小;人工唾液作用30d静摩擦力最小。     

正畸方丝转矩力的分析

目的研究正畸方丝的转矩力。方法运用自行研制的转矩测量仪测量0.46 mm×0.63 mm、0.48 mm×0.63 mm不锈钢方丝和相同截面尺寸的镍钛方丝在单个0.56 mm槽沟的中切牙托槽内的转矩力矩与转矩角度;根据转矩力矩与转矩角度,使用SPSS 11.0软件制作散点图,拟合出4种弓丝的负荷形变曲线,并据此建立直线回归方程;根据方程得出弓丝的抗扭刚度及转矩力矩为20 N·mm时的转矩角度。结果以上4种弓丝抗扭刚度分别为4.909、6.417、1.325、1.363 N·mm/°,达到20 N·mm转矩力矩时的转矩角度分别为19.14°、15.33°、36.83°、35.07°。结论相同截面尺寸不锈钢方丝的抗扭刚度明显大于镍钛方丝;两种截面尺寸镍钛方丝的抗扭刚度相差很小,而不锈钢方丝则相差较大。     

镍钛丝上加不锈钢管点焊阻挡曲矫治前牙闭锁

闭锁临床症状主要表现为上下切牙舌向倾斜,呈闭锁关系,下颌后缩,上下牙弓为远中关系或中性关系,颌间距离较低,面下1/3过短,上下前牙呈内倾型深覆为主要特征的错畸形.传统治疗方法很多.其中,较常见的有固定矫治器,先在上颌牙弓在安上带环,用直径0.35mm的圆丝颊面管的近中弯制欧米咖曲,前牙段开大垂直曲;或用带双曲舌簧的活动矫治器对错位牙施以矫治力,而使其向唇侧移动.笔者在治疗中主要采用0.35mm,0.40mm,0.45mm镍钛圆丝上直接加不锈钢管,在点焊机上点焊阻挡曲.阻挡曲位于的颊面管近中,弓丝的前段离开前牙弓4mm.如磨牙表现为远中关系,还可在阻挡曲远中安放镍钛推簧,改善磨牙关系,前牙也建立正常的上下切牙覆覆盖关系.当上切牙舌倾得到矫治后,下切牙才能唇向开展,同时下颌可自由地调动到正常位置.     

控根辅弓对上颌切牙转矩疗效的临床研究

目的：探讨控根辅弓对直丝弓矫治器患者的上颌切牙转矩效果。方法：选择22例安氏Ⅱ1拔牙矫治的患者,采用直丝弓矫治器矫治,在精细调整阶段配合控根辅弓对过度直立或内倾的上颌切牙进行正转矩。按主弓丝不同分为2组,14例主弓丝为0．46 mm ×0．64 mm 的不锈钢方丝,8例主弓丝为0．46 mm 的不锈钢圆丝。对22例上颌切牙转矩前后的 X 线头影测量结果采用 t 检验进行统计分析。结果：22例上颌切牙转矩后的 X 线头影测量结果显示,1-SN、UIa-NA 值增加（P ＜0．01）,控根辅弓对上切牙的正转矩效果明显;转矩的时间,主弓丝为圆丝上颌切牙转矩快于主弓丝为方丝,P ＜0．05。结论：在直丝弓矫治的精细调整阶段,配合前牙控根辅弓,是对内收后过度直立或舌倾的上颌切牙实现转矩的简单、有效的方法。     

扭转牙矫治的最适弓丝选择

本文采用建模－仿真方法计算出０．５５ｍｍＮ－Ｔ弓丝、０．５５ｍｍＮ－Ｔ垂直曲弓丝、０．５ｍｍ不锈钢弓丝和０．５ｍｍ不锈钢垂直曲弓丝对各牙齿能产生最适矫治力的角度，为方丝弓矫治扭转牙选择弓丝提供依据。     

扭转牙矫治的最适弓丝选择

本文采用建模－仿真方法计算出０．５ｍｍＮ－Ｔ弓丝、０．５ｍｍＮ－Ｔ垂直曲弓丝、０．５ｍｍ不锈钢弓丝和０．５ｍｍ不锈钢垂直曲弓丝对各牙齿能产生最适矫治力的角度（最适角度），为方丝弓矫治扭转牙选择弓丝提供依据。     

Torque Expression in Stainless Steel Orthodontic Brackets: A Systematic Review

Objective:To evaluate the quantitative effects on torque expression of varying the slot size of stainless steel orthodontic brackets and the dimension of stainless steel wire, and to analyze the limitations of the experimental methods used.Materials and Methods:In vitro studies measuring torque expression in conventional and self-ligating stainless steel brackets with a torque-measuring device, with the use of straight stainless steel orthodontic wire without second-order mechanics and without loops, coils, or auxiliary wires, were sought through a systematic review process.Results:Eleven articles were selected. Direct comparison of different studies was limited by differences in the measuring devices used and in the parameters measured. On the basis of the selected studies, in a 0.018 inch stainless steel bracket slot, the engagement angle ranges from 31 degrees with a 0.016 × 0.016 inch stainless steel archwire to 4.6 degrees with a 0.018 × 0.025 inch stainless steel archwire. In a 0.022 inch stainless steel bracket slot, the engagement angle ranges from 18 degrees with a 0.018 × 0.025 inch stainless steel archwire to 6 degrees with a 0.021 × 0.025 inch stainless steel archwire. Active stainless steel self-ligating brackets demonstrate an engagement angle of approximately 7.5 degrees, whereas passive stainless steel self-ligating brackets show an engagement angle of approximately 14 degrees with 0.019 × 0.025 inch stainless steel wire in a 0.022 inch slot.Conclusions:The engagement angle depends on archwire dimension and edge shape, as well as on bracket slot dimension, and is variable and larger than published theoretical values. Clinically effective torque can be achieved in a 0.022 inch bracket slot with archwire torsion of 15 to 31 degrees for active self-ligating brackets and of 23 to 35 degrees for passive self-ligating brackets with a 0.019 × 0.025 inch stainless steel wire.     

Evaluation of friction between ceramic brackets and orthodontic wires of four alloys

The purpose of this investigation was to determine the frictional resistance offered by ceramic brackets used in combination with wires of different alloys and sizes during in vitro translatory displacement of brackets. Findings with ceramic brackets were also compared with outcomes of treatment with stainless steel brackets. Stainless steel, cobalt-chromium, beta-titanium, and nickel-titanium wires of different cross-sectional sizes were tested in medium-twin monocrystalline ceramic brackets with both 0.018-inch and 0.022-inch slot sizes. The wires were ligated into the brackets with elastomeric modules. Brackets were moved along the wire by means of an Instron universal testing machine, and frictional force was measured by a compression cell and recorded graphically on an xy recorder. Wire friction in the ceramic brackets increased as wire size increased, and rectangular wires produced greater friction than round wires. Beta-titanium and nickel-titanium wires were associated with higher frictional forces than stainless steel or cobalt-chromium wires. These findings follow the same general trends as those found with stainless steel brackets; however, wires in ceramic brackets generated significantly stronger frictional force than did wires in stainless steel brackets.     

自制美学涂层弓丝表面形貌的研究

目的：对自制美学涂层弓丝表面粗糙度进行测试,并与传统不锈钢弓丝进行比较,在扫描电镜下观察弓丝的表面形貌。方法：分别测定经4种托槽（带金属槽沟的陶瓷托槽,普通托槽,陶瓷托槽,树脂托槽）摩擦过的及未经摩擦的0.018英寸的美学涂层不锈钢圆丝和0.018英寸的不锈钢圆丝的表面粗糙度,并在扫描电镜下观察弓丝的形貌特征。结果：未经摩擦过的涂层与未涂层弓丝间的表面粗糙度比较,无统计学意义;经托槽摩擦过的涂层与未涂层弓丝间的表面粗糙度比较,有统计学意义,且与不同托槽摩擦后弓丝表面粗糙度值不同,其中,与陶瓷托槽摩擦后的弓丝表面粗糙度和与带金属槽沟的陶瓷托槽,普通托槽及未摩擦的弓丝表面粗糙度存在统计学差异。结论：美学涂层弓丝符合口腔正畸临床使用要求。     

The friction and wear patterns of orthodontic brackets and archwires in the dry state

Frictional resistance at the bracket-archwire interface has been demonstrated to impede tooth movement when sliding mechanics are used. Thus, the coefficients of friction of titanium and stainless steel brackets used in conjunction with stainless and ion-implanted beta-titanium archwires were investigated using a single contact interface between the brackets and archwires. The wear patterns between the brackets and the.016- in flat archwire surfaces were also examined using scanning electron microscopy and energy dispersive x-ray analysis. Stainless steel brackets tested with. 016-in flat stainless steel wire surfaces recorded the lowest coefficient of static friction mean (0.289), whereas titanium brackets paired with.016-in flat ion-implanted beta-titanium wire surfaces produced the highest mean (0.767). Stainless steel brackets had significantly (P <.05) lower coefficients of friction than titanium brackets for all wires except.020-in round stainless steel wires. Ion-implanted beta-titanium wires generally had significantly larger coefficients of friction than stainless steel wires. The increased friction of the titanium and ion-implanted beta-titanium alloys is also reflected in the severity of their wear patterns. An inverse relationship between friction and archwire surface dimension was generally found for ion-implanted beta-titanium wires. Round stainless steel wires demonstrated lower coefficients of kinetic friction than the flat stainless steel wire surfaces.     

Influence of ceramic and stainless steel brackets on the notching of archwires during clinical treatment

The surface topography of 100 clinically used archwires of stainless steel, beta-, or nickel-titanium were investigated that had contacted either ceramic or stainless steel brackets. One group consisted of two sets: 60 wires with no treatment records accessed to bias analyses, and 40 wires for which extensive clinical records were available, half of which were used with ceramic or stainless steel brackets. A control group consisted of two sets: 30 unused wires comprised of five round and rectangular wires of each alloy, and four wires that were ligated and immediately removed from patients' mouths. After ultrasonic cleaning, each wire was inspected under an optical and/or a scanning electron microscope. Notches were categorized with regard to frequency, patterns, and severity, and mapped as a function of wire aspect (lingual, facial, and occlusal/gingival) and anatomical regions (molar, premolar, canine, and incisor). From these data the average severity of notch patterns and a notching index were derived. Although no recognizable defect patterns were observed in the control group, seven basic patterns were recognized for each wire cross-sectional shape in the clinically used wires. These wires appeared most damaged on their lingual aspect and least damaged on their facial aspect. With regard to anatomical regions, notching was prevalent in the anterior regions and sparse in the molar regions. The notch activity and the severity were nearly three times greater from ceramic brackets than from stainless steel brackets. Over one-third of all notches documented in ceramic bracket cases had severity numbers of 3 and penetrated at least one-quarter of each wire's dimension, However, over two-thirds of all notches documented in stainless steel bracket cases had severity numbers of 1. From these tabulations a theory of notch formation was proposed in which vertical movement from tooth or wire during mastication caused fretting wear, and horizontal movement during orthodontic procedures such as space closure, tipping, or bodily movement caused sliding wear.     

The wire material and cross-section effect on double delta closing loops regarding load and spring rate magnitude: an in vitro study.

The mechanical behavior of orthodontics closing loops, with three different wire materials (stainless steel, cobalt-chromium and titanium-molybdenum) and with different cross-sections and a double delta design, was studied in tension tests. The springs were stress-relieved, except the titanium-molybdenum wires. There were 72 sample springs, divided into 33 stainless steel, 26 cobalt-chromium and 13 titanium-molybdenum, activated at 0.5 mm intervals, from neutral position to 3.0 mm. It was hypothesized that loads, after spring activation, and spring rate, are dependent on cross-section, wire material, and activation. The analysis of variance and the Tukey-Kramer test were applied to verify the differences between all coupled averages of the loads. Regression analysis was also used to verify if closing loops behavior was in accordance with Hooke's law and to obtain the spring rate. The results show that the loads are dependent on activation, cross-section, and wire material. Titanium-molybdenum 0.017 x 0.025 inch (Ormco) springs showed the smallest loads and the best spring rate. (beta = 84.9 g/mm)     

The effect of long-term deflection on permanent deformation of nickel-titanium archwires

The clinician must now consider the alloy along with cross-sectional shape and size when selecting archwires. The purpose of this study is to quantify permanent deformation after long-term deflection of available nickel-titanium archwires. Nine nickel-titanium, one beta-titanium and one stainless steel archwires, .016 inch round, were deflected into orthodontic brackets of simulated archform. One lateral incisor was positioned to yield a deflection of 5 mm in a lingual direction. After wire deactivation, deformation was measured at 1, 14, and 28 days. Two-way ANOVA and Tukey's critical difference tests were used to determine statistical differences. The nickel-titanium wires exhibited better springback characteristics and less permanent deformation than the stainless steel and TMA wires. Several wires increased deformation as deflection time increased. No clinically significant difference was found between presently available nickel-titanium wires in terms of permanent deformation, long- or short-term.     

自制美学涂层弓丝摩擦力的实验研究

目的：对自制美学涂层弓丝的摩擦力进行测试,并与普通不锈钢弓丝比较。方法：在干燥条件下,模拟临床牙齿移动,分别测定0．018″美学涂层不锈钢圆丝和0．018″普通不锈钢圆丝与3种美学托槽（陶瓷托槽、树脂托槽、带金属槽沟的陶瓷托槽）组合的摩擦力并进行比较。同时比较与美学涂层弓丝组合时,3种托槽之间的摩擦力大小。结果：在与3种美学托槽组合时,美学涂层不锈钢圆丝与普通不锈钢圆丝的摩擦力虽有不同,但无显著性差异。3种美学托槽与美学涂层弓丝组合时,陶瓷托槽的摩擦力明显大于树脂托槽和带金属槽沟的陶瓷托槽,而后两者之间无统计学差异。结论：此种美学涂层弓丝符合口腔正畸临床使用要求。     

弓丝与结扎方法对摩擦力影响的实验研究

目的:了解4种弓丝和2种结扎方法对托槽与弓丝摩擦力的影响。方法:在干燥条件下,按正交实验设计,使用LJ-500型拉力实验机的微型测力计,测试4种弓丝与6种直丝托槽组合及采用2种结扎法时在后牙段的动、静摩擦力。所得数据进行方差分析和二次响应回归分析。结果:在弓丝与所有托槽组合中,0.018英寸×0.025英寸(1in=2.54cm)的不锈钢方丝动、静摩擦力最小,0.019英寸×0.025英寸的不锈钢方丝动、静摩擦力最大,0.018与0.020英寸不锈钢圆丝介于两者之间,但0.018英寸圆丝的动摩擦力较大,0.020英寸圆丝的静摩擦力较大。动、静摩擦力平均百分比从小到大依次为:0.019英寸×0.025英寸方丝、0.020英寸圆丝、0.018英寸×0.025英寸方丝、0.018英寸的圆丝。弹力橡皮圈结扎的动、静摩擦力及动、静摩擦力平均百分比均大于不锈钢丝结扎。结论:0.018英寸的不锈钢圆丝不适宜滑动机制;在0.022英寸系统的直丝托槽中,用0.019英寸×0.025英寸不锈钢方丝关闭间隙,应尽可能加强支抗控制;干燥条件下弹力橡皮圈结扎不利于托槽、弓丝滑动。     

彩色不锈钢托槽和弓丝的摩擦力实验

目的研究新型的彩色弓丝和托槽染色前后摩擦性状有无改变。方法将通过化学着色法得到的彩色不锈钢托槽、弓丝与常用的托槽、弓丝两两交叉分为四组(无色丝-无色槽、无色丝-有色槽、有色丝-无色槽、有色丝-有色槽)与5种尺寸(0.016、0.018、0.017×0.025、0.018×0.025、0.019×0.025英寸)弓丝结合,测试干燥状态下的静摩擦力。结果不论圆丝或方丝,各弓丝、托槽组合间摩擦力没有显著性差异。不锈钢圆丝的摩擦力小于方丝。结论化学着色对弓丝、托槽的摩擦力没有影响。