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。     

超滑结扎橡皮圈和常规结扎橡皮圈对摩擦力影响的对比研究

目的：探讨和比较超滑结扎橡皮圈和常规结扎橡皮圈在干燥和自然唾液条件下对摩擦力的影响。方法：选用超滑结扎橡皮圈和常规结扎橡皮圈、2种弓丝（0．019×0．025英寸方丝,0．018英寸圆丝）、MBT^TM直丝托槽组,模拟弓丝在后牙段在干燥和自然唾液条件下滑动,测量各组合的静、动摩擦力。结果：在于燥的条件下,无论在方丝组合还是圆丝组合,2种结扎橡皮圈静动摩擦力都无显著性差异。超滑结扎橡皮圈在自然唾液1h的条件下,与常规结扎橡皮圈结扎相比,在方丝组合,静摩擦力降低31.18％,动摩擦力降低21．66％;在圆丝组合,静摩擦力降低31．98％,动摩擦力降低28．67％。结论：超滑结扎橡皮圈在干燥条件下对静动摩擦力无显著影响。在自然唾液浸润1h的条件下,无论在方丝组合还是圆丝组合,超滑结扎橡皮圈能起到降低静动摩擦力的作用。     

脱落托槽热处理后对摩擦力影响的实验研究

目的测试热处理对托槽与弓丝间最大静摩擦力的影响。方法在干燥条件下,选取0.022×0.028英寸上颌尖牙不锈钢直丝托槽36枚,弓丝为0.019×0.025英寸不锈钢方丝。将36枚托槽随机分成三组,每组12枚,第一组不做任何处理,第二组、第三组托槽背板粘一薄层京津釉质粘结剂,热处理后用探针去除粘结剂,第三组托槽再进行超声清洗5分钟,分别测试这三组托槽与弓丝间最大静摩擦力。结果测得未经处理的上颌尖牙托槽与0.019×0.025英寸弓丝间最大静摩擦力值为74.67±12.73g;热处理及热处理后经超声清洗的托槽与弓丝间最大静摩擦力值分别是66.31±12.44g、61.97±13.47g。结论热处理及热处理后经超声清洗的托槽与弓丝间产生的最大静摩擦力值较未经任何处理的托槽与弓丝间产生的最大静摩擦力值明显减小。     

临床结扎力量与口内托槽沿不锈钢弓丝滑动的摩擦力

在正畸矫治体系中,弓丝和托槽之间的摩擦力会妨碍牙齿移动的速度,本研究检测托槽沿弓丝滑动时托槽结扎力量和咀嚼对摩擦力的影响。材料和方法根据量化标准,将实验对象分为不锈钢结扎丝紧结扎组、松结扎组和弹性结扎圈组,然后在不同环境条件下(咀嚼和非咀嚼),用特制的摩擦力测定装置进行口内和体外实验。实验矫治系统采用0°轴倾角和0°转矩的0.56mm×0.71mm(0.022in×0.028in)前磨牙不锈钢托槽和0.48mm×0.64mm0.019in×0.025in不锈钢弓丝,结扎圈为弹性橡皮圈和0.25mm0.010in不锈钢结扎丝。试验数据进行方差分析和TukeyHSD检验。结果和讨…     

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）.     

时效对正畸弓丝摩擦力影响的实验研究

目的探讨不锈钢丝在口内使用一段时间后其摩擦力所受到的影响。方法用0.018英寸的国产不锈钢圆丝、0.018英寸进口的不锈钢圆丝、0.019×0.025英寸进口不锈钢方丝分别在口内使用4周、8周、12周、16周、20周(n=20)。取尖牙远中与磨牙近中之间的弓丝,检测其摩擦系数并与新弓丝做比较。结果与新弓丝相比,使用过的进口不锈钢圆丝、进口不锈钢方丝摩擦力无明显变化,而国产的圆丝使用3个月后摩擦力变大。结论就摩擦力而言进口不锈钢丝在口内的使用周期较长。     

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。     

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。     

三种直丝托槽与弓丝组合滑动前后的扫描电镜观察

目的 :通过扫描电镜对三种常用国内、外直丝托槽与弓丝组合在滑动前后表面结构的研究 ,为临床使用这些托槽需注意那些问题提供理论指导。方法 :选用三种常用国内、外直丝托槽与 0 .0 19× 0 .0 2 5英寸不锈钢方丝组合 ,在滑动前后进行扫描电镜观察。结果 :(1)滑动前国内直丝托槽比国外直丝托槽表面粗糙。 (2 )、滑动后国内、外直丝托槽与弓丝都有明显磨损 ;与国内三比公司生产的滑动直丝托槽组合的 0 .0 19× 0 .0 2 5英寸不锈钢方丝有明显的锉刀状损伤痕。结论 :三种直丝托槽的表面粗糙程度明显不同 ,滑动后有明显磨损。因此 ,使用滑动法关闭间隙时 ,应重视托槽表面粗糙、磨损对摩擦力的影响 ,注意支抗控制。     

0．021&#215;0．025英寸方丝引起前牙唇舌向倾斜度变化的研究

目的探讨在0.022×0.028″的直丝弓托槽中先后使用0.019×0.025″和0.021×0.025″的方形弓丝对于前牙的唇舌向倾斜度所产生的影响.方法在20例非拔牙矫治患者中选出10例前牙唇舌向倾斜度欠满意的患者,对其使用0.019×0.025″和0.021×0.025″两种方丝时的头颅侧位片进行测量,对0.021×0.025″的方丝引起的前牙唇舌向倾斜度的变化进行统计分析.结果将0.019×0.025″不锈钢方丝更换为0.021×0.025″方钛丝2个月后,其引起的代表前牙唇舌向倾斜度的测量指标的变化有统计学意义(P＜0.01).结论在使用0.019×0.025″不锈钢方丝后,换用0.021×0.025″的方钛丝并使其有一定的作用时间,可以引起前牙唇舌向倾斜度的明显变化.     

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。     

Evaluation of methods of archwire ligation on frictional resistance

The aim of the study was to investigate the effect of elastomeric type and stainless steel (SS) ligation on frictional resistance using a validated method. To assess the validity of the new test system to measure mean frictional forces, SS and TMA wires, each with dimensions of 0.017 x 0.025 and 0.019 x 0.025 inches, were used in combination with a self-ligating Damon II bracket or a conventional preadjusted edgewise premolar SS bracket without ligation. Four types of elastomeric module, purple, grey, Alastik or SuperSlick, and a pre-formed 0.09 inch SS ligature were then assessed as methods of ligation using preadjusted edgewise premolar SS brackets. The specimens were tested on a Nene M3000 testing machine, with a crosshead speed of 5 mm/minute and each test run lasted for 4 minutes. Each bracket/wire combination with each method of ligation was tested 10 times in the presence of human saliva and the mean frictional force was recorded. The mean frictional forces were compared using three-way analysis of variance. The Damon II self-ligating bracket and unligated conventional SS bracket produced negligible mean frictional forces with any of the wires tested. For the 0.017 x 0.025 SS, 0.019 x 0.025 SS or 0.019 x 0.025 inch TMA wires, SS ligatures produced the lowest mean frictional forces. With the 0.017 x 0.025 TMA wire, purple modules produced the lowest mean frictional force. There was no consistent pattern in the mean frictional forces across the various combinations of wire type, size and ligation method. Under the conditions of this experiment, the use of passive self-ligating brackets is the only method of almost eliminating friction.     

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.     

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.     

Friction produced by types of elastomeric ligatures in treatment mechanics with the preadjusted appliance

The objective was to compare the frictional forces generated by new nonconventional passive elastomeric ligatures (NCL) and conventional elastomeric ligatures (CL) under dry conditions. An experimental model reproducing the right buccal segment of the upper arch and consisting of five stainless steel 0.022-inch preadjusted brackets (from the second premolar through the central incisor) was used to assess both static and kinetic frictional forces produced by NCL and CL. The frictional forces generated by the 0.019 x 0.025-inch stainless steel wire with the two types of elastomeric ligatures were recorded by sliding the wire into the aligned brackets. The friction produced by the 0.014-inch superelastic nickel titanium wire was evaluated both in the presence of aligned brackets and of three-mm misaligned canine bracket. The amount of both static and kinetic frictions were minimal (<10 g) in the NCL group in the presence of aligned brackets with both types of wires, whereas it ranged from a minimum of 95.6 g for the 0.014-inch superelastic nickel titanium wire to a maximum of 590.7 g for the 0.019 x 0.025-inch stainless steel wire when using CL. The amount of both static and kinetic frictions in the presence of a misaligned canine bracket in the NCL group were less than half of that shown by the CL group. A recently developed passive ligature system is able to produce significantly lower levels of frictional forces in vitro when compared with conventional elastomeric modules.     

Evaluation of friction of conventional and metal-insert ceramic brackets in various bracket-archwire combinations.

The purpose of the study was to measure and compare the level of frictional resistance generated between conventional ceramic brackets (Transcend Series 6000, 3M Unitek, Monrovia, Calif), ceramic brackets with stainless steel slot (Clarity, 3M Unitek), conventional stainless steel brackets (Victory Series, 3M Unitek), and 3 different orthodontic wire alloys: stainless steel (stainless steel, SDS Ormco, Glendora, Calif), nickel-titanium (Ni-Ti, SDS Ormco), and beta-titanium (TMA, SDS Ormco). All brackets had a 0.022-in slot, and orthodontic wire alloys were tested in 3 different sections: 0.016 in, 0.017 x 0.025 in, and 0.019 x 0.025 in. Each of the 27 bracket-archwire combinations was tested 10 times, and each test was performed with a new bracket-wire sample. Static and kinetic friction were measured on a specially designed apparatus. All data were statistically analyzed (analysis of variance and Scheffé for the bracket effect, Kruskal-Wallis and Mann Whitney for the alloy and section effects). Metal-insert ceramic brackets generated significantly lower frictional forces than did conventional ceramic brackets, but higher values than stainless steel brackets, in agreement with the findings of the few previous reports. Beta-titanium archwires had higher frictional resistances than did stainless steel and nickel-titanium archwires. No significant differences were found between stainless steel and nickel-titanium archwires. All the brackets showed higher static and kinetic frictional forces as the wire size increased. Metal-insert ceramic brackets are not only visually pleasing, but also a valuable alternative to conventional stainless steel brackets in patients with esthetic demands.     

A comparison of self-ligating and conventional orthodontic bracket systems.

Abstract

This ex-vivo study compared the static frictional resistance of three self-ligating brackets with a conventional steel-ligated Ultratrimm bracket. The effects of archwire size (0.020, 0.019 x 0.025 and 0.021 x 0.025-inch), bracket/archwire angulation (0, 5 and 10 degrees) and the presence of unstimulated human saliva were investigated. The study demonstrated that both increases in wire size and bracket/archwire angulation resulted in increased static frictional resistance for all bracket types tested, with the presence of saliva having an inconsistent effect. Mobil-Lock Variable-Slot had the least friction for all wires for 0 degree angulation. However, with the introduction of angulation, the values were comparable to those of the other brackets. Activa brackets had the second lowest frictional resistance, although high values were found with 0.019 x 0.025-inch wires. SPEED brackets demonstrated low forces with round wires, although with rectangular wires or in the presence of angulation, friction was greatly increased. Ultratrimm brackets produced large individual variation, confirming the difficulty in standardizing ligation force, although under certain conditions, significantly larger frictional forces were observed. In conclusion, self-ligating brackets showed reduced frictional resistance in comparison to steel ligated brackets only under certain conditions.     

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目的对自锁托槽与传统托槽滑动阻力的大小及变化规律进行对比研究。方法本研究于2011年9—12月在山西医科大学口腔医院和太原理工大学应用力学与生物医学研究所共同完成。根据人体实际弹性模量比例制作含牙周膜的上颌仿真模型,测试自锁托槽和传统托槽分别与0．016英寸、0．018英寸的镍钛丝和0．017英寸×0．022英寸、0．018英寸×0．025英寸、0．019英寸x0．025英寸的不锈钢方丝匹配时的滑动阻力大小。结果使用同种弓丝时,滑动阻力由小到大排列：DamonQ被动自锁托槽〈Tomy主动自锁托槽〈传统金属托槽,两两比较差异有统计学意义（P〈0．05）。同一种托槽情况下,除0．019英寸×0．025英寸不锈钢方丝外,其余滑动阻力都随弓丝直径的增大而增大,且两两比较差异有统计学意义（P〈0．05）。结论临床实践中托槽类型与弓丝的匹配对滑动阻力的影响十分重要,从而实现牙齿的快速有效移动。