两种不同被动式自锁托槽摩擦力的实验研究

目的:探讨2种被动式自锁托槽系统(SmartClip,Damon3)分别和不同弓丝组合时在后牙段所产生的摩擦力差异.方法:24℃及干燥条件下,分别测试这2种被动自锁托槽系统与3种弓丝(0.36 mm NiTi圆丝、0.48 mm×0.64 mm NiTi方丝、0.48 mm×0.64 mm不锈钢方丝)组合时在后牙段的动、静摩擦力.结果:当使用0.36 mm NiTi圆丝时,SmartClip与Damon3自锁托槽的摩擦力相比无显著差异(P>0.05).当使用0.48mm×0.64 mm NiTi方丝和不锈钢方丝时,SmartClip与Damon3自锁托槽的摩擦力相比差异有显著性(P<0.05),并且SinartClip大于Damon3自锁托槽的摩擦力.结论:SmarlClip自锁托槽可以有效调节摩擦力大小,在使用较小尺寸弓丝时可达到同Damon3自锁托槽相似的低摩擦力效果,当放入0.48 mm×0.64 mm以上的方丝时摩擦力迅速增加.     

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。     

Lock-loose托槽与传统托槽摩擦力特性的比较研究

目的 在干燥和人工唾液环境中测量Lock-loose托槽结扎中间翼和结扎全翼时与弓丝之间滑动摩擦力和静摩擦力的大小,并与传统四翼托槽和自锁托槽进行对比。方法 应用原子力显微镜观察不锈钢弓丝与不同托槽摩擦前后的表观形貌。选用Lock-loose托槽、传统四翼托槽和自锁托槽,分别与0.406 4 mm、0.457 2 mm不锈钢圆丝和0.457 2 mm×0.634 9 mm、0.482 6 mm×0.634 9 mm不锈钢方丝组合,其中Lock-loose托槽使用结扎中间翼和结扎全翼两种结扎方式。使用电子万能力学实验机测量干燥和人工唾液两种环境下弓丝在托槽内滑动的动、静摩擦力。结果 不同尺寸弓丝与不同托槽摩擦前后的表面粗糙度无明显差异（P>0.05）;Lock-loose托槽结扎中间翼与4种弓丝组合的动、静摩擦力均接近于0,与传统四翼托槽有明显差异（P<0.05）;与0.457 2 mm×0.634 9 mm不锈钢方丝组合时,Lock-loose托槽结扎全翼可以获得最大动、静摩擦力,与传统四翼托槽和自锁托槽的差异有统计学意义（P<0.05）;人工唾液环境中的摩擦力小于干燥环境中的摩擦力（P<0.05）。结论 Lock-loose托槽可以通过不同的结扎方式调节并获得临床所需的摩擦力,有效解决了低摩擦力与强支抗控制的矛盾问题。     

不同自锁托槽摩擦力的实验研究

目的：探讨干燥条件下,被动自锁托槽系统与主动自锁托槽系统分别和不同弓丝组合时,在后牙段所产生的摩擦力差异.方法：在干燥条件下,分别测试2种被动自锁托槽系统（Damon 3,3M Smart clip）、2种主动自锁托槽系统（Tomy,Time 2）与3种弓丝（0.019×0.025英寸NiTi方丝、0.019×0.025英寸SS方丝、0.014英寸NiTi圆丝）组合在后牙段的动、静摩擦力.结果：0.019×0.025英寸NiTi方丝组中,被动自锁托槽与主动自锁托槽的摩擦力比较均有显著性差异,大小依次为Tomy＞Time2＞3M SmartClip＞Damon3自锁托槽的摩擦力;0.019×0.025英寸方丝组中,Tomy自锁托槽的摩擦力最大,然后依次为Time 2、3M SmartClip与Damon3自锁托槽（被动自锁托槽的摩擦力无显著性差异）;0.014英寸NiTi圆丝组中,4种自锁托槽的摩擦力无明显差异p＞0.05）.同一自锁托槽系统时,0.019×0.025英寸NiTi方丝的摩擦力最大,其次为0.019×0.025英寸SS方丝、0.014英寸NiTi圆丝.结论：在0.019×0.025英寸SS弓丝-自锁托槽组合中,被动自锁托槽系统产生的摩擦力＜主动自锁托槽系统（p＜0.05）：在0.014英寸SS弓丝-自锁托槽组合中,被动自锁托槽系统产生的摩擦力与主动自锁托槽系统的无明显差异（p＞0.05）.     

自锁托槽和传统托槽摩擦力的实验研究

目的:测量自锁托槽和传统托槽与正畸弓丝成不同接触角角度时沿着各种弓丝滑动时所需克服的摩擦力大小,分析托槽、接触角、弓丝材料对弓丝与托槽之间摩擦力的影响.方法:本实验用于检测的托槽包括自锁托槽(DamonⅢ,In-ovation)和传统金属直丝弓托槽,所有托槽均选用上颌第一前磨牙托槽.应用Instron8841万能材料测试机测量托槽沿着各种弓丝(0.016in镍钛丝、0.016in澳丝、0.018×0.025in镍钛丝、0.018×0.025in不锈钢丝)滑动时摩擦力的大小.改变托槽与弓丝之间的角度,测量托槽与弓丝成不同角度时(0°、3°、6°、9°)摩擦力的大小.结果:自锁托槽的摩擦力在各种角度下均明显小于传统托槽.随着接触角的增加,自锁托槽和传统托槽摩擦力均增大,不锈钢丝和澳丝比镍钛丝摩擦力增加得更迅速.结论:托槽的类型、弓丝的材料和尺寸、接触角的变化对弓丝与托槽间摩擦力有显著的影响.自锁托槽能明显减小摩擦力.     

不同结扎方式对舌侧托槽静摩擦力的影响

目的：探讨在不同结扎方式下,舌侧托槽在牙弓后段所产生静摩擦力的差异。方法：测试2种舌侧托槽系统（STb、e·Brace）与4种弓丝（0．016英寸镍钼合金丝、0．016英寸不锈钢圆丝、0．016×0．022英寸镍钼合金丝、、0．016×0．022英寸不锈钢方丝）组合在3种结扎方式下的静摩擦力。结果：不同结扎状态下,舌侧托槽－弓丝间的静摩擦力有显著性差异（P＜0．05）。结论：舌侧托槽－弓丝组合的静摩擦力随结扎力的增大而增大。     

FAS自锁托槽与传统自锁托槽的摩擦力对比研究

目的测量FAS托槽在两种不同调节状态下与正畸钢丝之间的摩擦力大小,并与DamonⅢ和SPEED两种传统自锁托槽进行对比。方法制作尺寸放大20倍的FAS、DamonⅢ和SPEED托槽钢制模型,同时制作放大20倍的钢制圆丝和方丝,采用拉力传感器测量托槽与弓丝间摩擦力的大小。实验中FAS托槽分为两种调节状态：垫片完全收入和与弓丝平面无压力状态相切后旋转0.5圈。结果在垫片完全收入的状态下,FAS托槽与直径8.128 0 mm的不锈钢圆丝之间的动静摩擦力与DamonⅢ和SPEED托槽均无统计学差异（P>0.05）;在使用9.144 0 mm×12.700 0 mm不锈钢方丝时,FAS托槽与方丝之间的动静摩擦力与DamonⅢ托槽无统计学差异（P>0.05）,而低于SPEED托槽,且有统计学差异（P<0.05）。当垫片与弓丝平面无压力状态相切后旋转0.5圈时,FAS托槽与圆丝、方丝的动、静摩擦力均明显高于DamonⅢ和SPEED托槽（P<0.01）。结论FAS托槽可以有效调节摩擦力的大小,在无压力状态下,托槽与弓丝间的摩擦力与DamonⅢ托槽相似;在有压力状态下,可以有效锁定弓丝,防止弓丝滑动。     

两种不同弹力结扎对滑动摩擦力大小影响的体外实验研究

目的通过体外实验研究MBT金属托槽应用两种不同的弹力结扎时滑动摩擦力的大小。方法选择3M公司的上颌第二双尖牙MBTmini金属托槽和0．46×0．64mm（0．018×0．025英寸）不锈钢弓丝,分别采用意大利Leone公司生产的Slide^TM结扎圈和美国TP公司生产的传统弹力圈结扎,应用自行设计开发的摩擦力测试仪,弓丝沿托槽低速滑动,并在滑动中保持特定的托槽——弓丝成角,共计12个角度。测量每一种弓丝、不同角度下的滑动摩擦力大小。结果在被动状态下两种结扎方式的滑动摩擦力均基本保持不变,Slide^TM结扎的摩擦力非常小,几乎可以忽略不计;在主动状态下,摩擦力随角度增加而增大,slide^TM结扎产生的滑动摩擦力仍明显小于传统弹力结扎。结论应用LeoneSlide^TM结扎圈,可以显著减小矫治器的滑动摩擦力。     

国产陶瓷托槽与金属弓丝间滑动摩擦力的研究

目的检测体外条件下国产多晶体氧化铝陶瓷托槽与金属弓丝在不同夹角时的滑动摩擦力,为其改良提供参考信息。方法利用摩擦力测量装置检测弓丝与槽沟的夹角分别为0°和5°时,国产陶瓷托槽分别与0.016、0.016×0.022、0.019×0.025英寸不锈钢丝和镍钛丝间的滑动摩擦力,每组样本量为10。对照组为临床常用多晶体氧化铝陶瓷托槽(Crystaline IV)。结果国产陶瓷托槽的摩擦力显著高于Crystaline IV,且除0°夹角、0.016英寸不锈钢圆丝和镍钛圆丝及0.016×0.022英寸不锈钢方丝外,其余情况下两种陶瓷托槽间摩擦力的差异有显著性(P0.01)。镍钛丝产生的摩擦力高于不锈钢丝,弓丝尺寸增加,摩擦力增加,弓丝与槽沟夹角为5°产生的摩擦力高于0°。结论国产陶瓷托槽的摩擦力性能不能满足临床使用的要求,需要进一步改良。     

湿润状态下托槽与弓丝间动摩擦力的实验研究

目的:探究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动摩擦力状况.方法:在人工唾液条件下,4个时间段:0、15、30、45 d,使用Instron万能材料力学实验机,模拟弓丝在后牙段滑动,按正交设计测试4种直丝托槽与4种弓丝组合在后牙段的动摩擦力.结果:3M MBT托槽的动摩擦力最小,0.48mm×0.64哪方丝的动摩擦力最大,0.46 mm圆丝的动摩擦力最小.弓丝、托槽组合在人工唾液条件下作用15 d动摩擦力最大、30 d动摩擦力最小.结论:0.46 mm圆丝的动摩擦力最小;人工唾液作用30 d动摩擦力最小;3M MBT托槽比较适合于滑动法关闭问隙.     

唇舌侧托槽转矩控制性能的有限元对比分析

目的：分析唇舌侧托槽转矩控制性能的差异,同时探讨不同材质不同尺寸的弓丝对舌侧托槽转矩控制的影响规律。方法：建立左上尖牙到右上尖牙的唇舌侧托槽三维有限元模型,在弓丝尺寸及材质不同的情况下,模拟临床左上中切牙转矩加载±20°。结果：随着转矩角度的增大,唇舌侧托槽转矩值逐渐增大,舌侧托槽转矩值为唇侧托槽的3～5倍;0．48 mm ×0．64 mm 弓丝的转矩值大于0．43 mm ×0．64 mm;弓丝尺寸相同时,不锈钢丝（SS）,β－钛丝（TMA）,镍钛丝（NiTi）,转矩值依次减小。结论：唇舌侧托槽转矩均随着转矩角度和弓丝的弹性模量的增大而增大;在相同的转矩角度下,舌侧托槽产生的转矩值大于唇侧托槽;舌侧托槽的转矩值与弓丝尺寸及材质有关。     

Frictional forces between lingual brackets and archwires measured by a friction tester

Frictional resistance tends to rapidly increase as the angle between a bracket and an archwire increases beyond a critical angle. The purpose of this study was to determine a new measuring method with a pin on disk friction tester for the measurement of the frictional force between lingual brackets and archwires. A lingual bracket is different from a labial bracket in dimensions and in some clinical aspects. The influence of artificial saliva was also surveyed. Two brands of lingual brackets and one brand of labial standard bracket with an 0.018-inch slot size were used. Archwires of three alloys (stainless steel [SS], Ormco; beta-Titanium [TM], Ormco; cobalt-chrome, [EL], RMO) with 0.016 x 0.022- and 0.017 x 0.025-inch dimensions were used. Measurements were conducted with an angular velocity of 0.6 degrees/s for 90 seconds and a normal force of 100 g at 25 degrees C in a dry and 34 degrees C in an artificial saliva environment. For SS and EL archwires, the frictional force with the FJT bracket was greater than that with ORM bracket (P < .01). Compared with SS and TM archwires, 0.016 x 0.022-inch EL archwire showed a higher frictional force with two lingual brackets (P < .01). Significant differences in frictional force existed between dry and artificial saliva environments (P < .05), and the effects varied by the bracket-archwire couples. The estimated critical contact angles were greater than the theoretical values. This new method can be a useful protocol for measurement of frictional force because it can measure the frictional force under the conditions of continuous angular change between bracket and archwire.     

不同陶瓷托槽与金属弓丝间摩擦力的研究

目的 研究不同类型陶瓷托槽与金属弓丝间的摩擦力,为临床应用及研制摩擦性能优良的陶瓷托槽提供参考.方法 选取正畸临床上常用的三种陶瓷托槽作为研究对象,一种金属托槽作为对照组.利用MTSTytron250微力实验机检测托槽与三种金属弓丝在不锈钢丝结扎下的最大静摩擦力和平均动摩擦力.结果 金属托槽与不锈钢圆丝间的最大静摩...     

陶瓷托槽与金属弓丝第二序列成角状态下摩擦性能的研究

目的研究陶瓷托槽与金属弓丝在第二序列成角状态下的摩擦力,探讨影响托槽弓丝间摩擦力的因素。方法进行托槽外观形貌的测量与观察,计算托槽与弓丝第二序列成角下的临界角,并设计带可调节罗盘的载物台,用MTS Tytron250微力试验机体外测试三种陶瓷托槽（A、B、C）和一种金属托槽（D）与0.016英寸不锈钢圆丝（SS）在第二序列成角分别为0度、2度、5度、8度时的最大静摩擦力和滑动摩擦力。结果与0.016英寸SS的摩擦力总体表现出B托槽〉C托槽〉A托槽〉D托槽的趋势,在四种成角状态下的最大静摩擦力随角度加大而增大,总体表现为0度到2度的摩擦力增加没有显著性,增大夹角后摩擦力增加量不同托槽间有差异：A托槽与弓丝在2度到5度成角状态下的摩擦力增加没有显著性,而5度到8度的摩擦力有显著增加;B托槽在2度到5度摩擦力有显著增加,而5度到8度摩擦力增加不显著;虽然2度到5度摩擦力增大没有显著性,但8度与0度状态下相比,C托槽与弓丝间的摩擦力有显著增加;D托槽在2度、5度、8度时摩擦力间差异无显著性。结论选用带金属槽沟的陶瓷托槽,增加陶瓷托槽边缘的圆钝程度等能减缓牙齿移动中托槽-弓丝成角引起的滑动阻力增加;使用传统陶瓷托槽要注意充分排齐。     

国产直丝陶瓷托槽摩擦力性能的研究

目的研究国产直丝陶瓷托槽的摩擦力性能。方法利用MTS Tytron250微力试验机测定我院与清华大学联合研制开发的下颌尖牙位直丝陶瓷托槽与0．016英寸不锈钢圆丝、0．016×0．022英寸不锈钢方丝、0．016英寸镍钛丝在不锈钢丝结扎方式下的摩擦力,并以一种进口陶瓷托槽作为对照组。结果国产直丝陶瓷托槽的最大静摩擦力与对照组陶瓷托槽相比差异无显著统计学意义,平均动摩擦力比对照组陶瓷托槽显著降低。结论国产直丝陶瓷托槽的摩擦性能可以满足临床需要。     

A comparative in vitro study of frictional resistance between lingual brackets and stainless steel archwires

Friction between archwires and labial brackets has received considerable attention; however, information on the frictional behaviour of commercially available lingual brackets is limited. The aim of this study was to investigate the frictional resistance resulting from a combination of lingual orthodontic brackets (7th Generation, STb, Magic, and In-Ovation L) and stainless steel archwires at 0, 5, and 10 degrees of second-order angulation. Each bracket type (n = 30) was tested with three different sizes of archwires. Static and kinetic frictional forces were evaluated with a universal testing machine. Statistical analysis of the data was performed with non-parametric Kruskal-Wallis and Dunn's multiple comparison tests. All tested brackets showed higher frictional forces as the wire size and second-order angulation increased. The lowest friction was found with In-Ovation L brackets and 0.016 inch archwires at 0 degrees angulation, and the greatest friction with a combination of STb brackets and 0.017 × 0.025 inch archwires at 10 degrees angulation. For all combinations, Magic and In-Ovation L brackets showed lower frictional resistance when compared with 7th Generation and STb brackets. The slot width (occluso-gingival dimension) of the brackets, measured using the optics of a microhardness machine, showed that all brackets were oversized and that Magic brackets had the largest slot width. Surface roughness of the brackets investigated using atomic force microscopy and scanning electron microscopy, demonstrated that the 7th Generation brackets had the greatest surface roughness.     

An in vitro investigation of the influence of self-ligating brackets, low friction ligatures, and archwire on frictional resistance

This study, performed using a specially designed apparatus that included 10 aligned brackets, evaluated the frictional resistance generated by conventional stainless steel (SS) brackets (Victory Series), self-ligating Damon SL II brackets, Time Plus brackets, and low-friction ligatures (Slide) coupled with various SS, nickel-titanium (NiTi), and beta-titanium (TMA) archwires. All brackets had a 0.022-inch slot and the orthodontic wire alloys were 0.016, 0.016 x 0.022, and 0.019 x 0.025 inch NiTi, 0.017 x 0.025 inch TMA, and 0.019 x 0.025 inch SS. Each bracket-archwire combination was tested 10 times. Coupled with 0.016 inch NiTi, Victory brackets generated the most friction and Damon SL II the least (P < 0.001); with 0.016 x 0.022 inch NiTi, the self-ligating brackets (Time and Damon SL II) generated significantly lower friction (P < 0.001) than Victory Series and Slide ligatures; with 0.019 x 0.025 inch SS or 0.019 x 0.025 inch NiTi, Slide ligatures generated significantly lower friction than all other groups. No difference was observed among the four groups when used with a 0.017 x 0.025-inch TMA archwire. These findings suggest that the use of an in vitro testing model that includes 10 brackets provides information about the frictional force of the various bracket-archwire combinations.     

Quantified simulation of canine retraction: evaluation of frictional resistance

The purpose of this study was to evaluate the frictional resistance of various bracket/archwire combinations. The friction testing apparatus allowed dynamic and progressive bracket tipping and uprighting concurrent with linear bracket traction which experimentally approximated canine retraction with sliding mechanics. Multiple ANOVA using general linear models procedure demonstrated significant effects (P < 0.05) for bracket type, archwire type, archwire size, and archwire shape, as well as pair-wise interactions for bracket type/archwire type, bracket type/archwire size, bracket type/archwire shape, archwire type/archwire size, archwire type/archwire shape, and archwire size/archwire shape. Duncan’s multiple range test (P < 0.05) revealed the general trends regarding frictional performance of brackets and archwires tested, while Least squares means table (P < 0.05) illustrated significant interactions of pair-wise factors that differed from the general trends. It was concluded that: (1) Ceramic brackets with and without metal slots had the greatest friction followed by metal brackets, active self-ligating brackets, variable self-ligating brackets, and passive self-ligating brackets. (2) Stainless steel and braided stainless archwires measured greater friction than nickel-titanium. (3) Smaller dimension wires had less friction than larger wires, and round wires had less friction than rectangular wires. In addition, consideration of specific bracket-archwire coupling appear to reduce the frictional resistance with sliding.     

Factors affecting friction in the pre-adjusted appliance

A jig was constructed to measure the frictional forces created by various tip and torque values in association with two types of straightwire bracket moving along tainless steel (SS) archwires. Forces were measured during translation of the bracket using an Instron machine. Steel and cobalt chromium brackets were tested in association with 0.019 x 0.025 and 0.021 x 0.025 inch steel archwires at tips from 0 to 3 degrees and torque values in 2 degree increments from 0 to 6 degrees.The mean values for static (2.2 N) and kinetic (2.1 N) friction were very similar (P = 0.71), as were the overall friction values for stainless steel (2.1 N) and chromium cobalt (2.2 N) brackets of similar dimensions (P = 0.44). Use of 0.021 x 0.025 inch wire produced three times as much friction as 0.019 x 0.025 inch wire, 3.0 N against 1.2 N (P < 0.01). Increased tip and torque were associated with highly significant increases in friction (P < 0.01). Every degree of tip produced approximately twice as much friction as comparable torque. The main conclusion of the study was that space closure should be completed on a 0.019 x 0.025 inch archwire before a 0.021 x 0.025 inch wire is used to complete tooth alignment.