自锁托槽及弓丝材质对转矩效能的影响

目的探讨自锁托槽系统与不同弓丝组合的转矩效能的差异及变化规律。方法分别测试2种被动自锁托槽系统（Damon3、SmartClip）、2种主动自锁托槽系统（Time2、OPA—K）与2种弓丝（0．019×0．025英寸镍钛方丝、0．019×0．025英寸不锈钢方丝）组合的转矩效能。结果（1）除了SmartCliD与Damon3自锁托槽（P=1．000）、OPA—K与Time2自锁托槽（P=0．999）的转矩效能间差异无统计学意义外．其他自锁托槽间的转矩效能的差异均有统计学意义（P〈0．001）;（2）0．019×0．025英寸镍钛方丝、0．019×0．025英寸不锈钢方丝相同自锁托槽组间转矩效能的差异有统计学意义（P〈0．001）。结论被动自锁托槽的转矩效能明显低于主动自锁托槽,不同弓丝转矩效能的差异与边缘斜面有关。     

Debris and friction of self-ligating and conventional orthodontic brackets after clinical use

Objective:To compare the degree of debris and friction of conventional and self-ligating orthodontic brackets before and after clinical use.Materials and Methods:Two sets of three conventional and self-ligating brackets were bonded from the first molar to the first premolar in eight individuals, for a total of 16 sets per type of brackets. A passive segment of 0.019 × 0.025-inch stainless steel archwire was inserted into each group of brackets. Frictional force and debris level were evaluated as received and after 8 weeks of intraoral exposure. Two-way analysis of variance and Wilcoxon signed-rank test were applied at P < .05.Results:After the intraoral exposure, there was a significant increase of debris accumulation in both systems of brackets (P < .05). However, the self-ligating brackets showed a higher amount of debris compared with the conventional brackets. The frictional force in conventional brackets was significantly higher when compared with self-ligating brackets before clinical use (P < .001). Clinical exposure for 8 weeks provided a significant increase of friction (P < .001) on both systems. In the self-ligating system, the mean of friction increase was 0.21 N (191%), while 0.52 N (47.2%) was observed for the conventional system.Conclusion:Self-ligating and conventional brackets, when exposed to the intraoral environment, showed a significant increase in frictional force during the sliding mechanics. Debris accumulation was higher for the self-ligating system.     

自锁托槽对关闭拔牙间隙阶段滑动阻力的影响

目的 比较在牙齿关闭拔牙间隙过程中不同自锁托槽和传统托槽与不锈钢丝组合所产生的滑动阻力。方法 在干燥环境下,分别选择2种自锁托槽(被动Damon^®和主动Tomy^®)和传统托槽的2种结扎方式(橡皮结扎圈和结扎丝)与0.019×0.025英寸不锈钢丝组合,测量严重牙列拥挤患者在拔牙后排齐整平的下颌模型上关闭拔牙间隙阶段的滑动阻力。采用方差分析的方法对各项测量数据进行统计学处理。结果 在关闭拔牙间隙阶段,不同托槽组合、组间的滑动阻力的差异均具有显著的统计学意义(P<0.01),最大静摩擦力和滑动摩擦力由小到大依次为被动Damon组<主动Tomy组<结扎丝结扎组<结扎圈结扎组。结论 在关闭拔牙间隙阶段,被动自锁托槽的滑动阻力明显小于主动自锁托槽的滑动阻力,自锁托槽的滑动阻力明显小于传统托槽的滑动阻力。     

Maxillary canine retraction with self-ligating and conventional brackets: A randomized clinical trial

Objective:To measure space closure during the retraction of upper permanent canines with self-ligating and conventional brackets.Materials and Methods:Fifteen patients who required maxillary canine retraction into first premolar extraction sites as part of their orthodontic treatment completed this study. In a random split-mouth design, the retraction of upper canines was performed using an elastomeric chain with 150 g of force. The evaluations were performed in dental casts (T0, initial; T1, 4 weeks; T2, 8 weeks; T3, 12 weeks). The amount of movement and the rotation of the canines as well as anchorage loss of the upper first molars were evaluated.Results:There was no difference between self-ligating and conventional brackets regarding the distal movement of upper canines and mesial movement of first molars (P > .05). Rotation of the upper canines was minimized with self-ligating brackets (P < .05).Conclusion:Distal movement of the upper canines and anchorage loss of the first molars were similar with both conventional and self-ligating brackets. Rotation of the upper canines during sliding mechanics was minimized with self-ligating brackets.     

Effects of self-ligating and conventional brackets on halitosis and periodontal conditions

Objective:To evaluate the effects of fixed orthodontic treatment with steel-ligated conventional brackets and self-ligating brackets on halitosis and periodontal health.Materials and Methods:Sixty patients, at the permanent dentition stage aged 12 to 18 years, who had Angle Class I malocclusion with mild-to-moderate crowding were randomly selected. Inclusion criteria were nonsmokers, without systematic disease, and no use of antibiotics and oral mouth rinses during the 2-month period before the study. The patients were subdivided into three groups randomly: the group treated with conventional brackets (group 1, n  =  20) ligated with steel ligature wires, the group treated with self-ligating brackets (group 2, n  =  20), and the control group (group 3, n  =  20). The periodontal records were obtained 1 week before bonding (T1), immediately before bonding (T2), 1 week after bonding (T3), 4 weeks after bonding (T4), and 8 weeks after bonding (T5). Measurements of the control group were repeated within the same periods. The volatile sulfur components determining halitosis were measured with the Halimeter at T2, T3, T4, and T5. A two-way repeated measures of analysis of variance (ANOVA) was used to compare the groups statistically.Results:No statistically significant group × time interactions were found for plaque index, gingival index, pocket depth, bleeding on probing, and halitosis, which means three independent groups change like each other by time. The risk of tongue coating index (TCI) being 2 was 10.2 times higher at T1 than at T5 (P < .001). Therefore, the probability of higher TCI was decreased by time in all groups.Conclusions:The self-ligating brackets do not have an advantage over conventional brackets with respect to periodontal status and halitosis.     

Canine retraction rate with self-ligating brackets vs conventional edgewise brackets

Objective:To compare the rates of retraction down an archwire of maxillary canine teeth when bracketed with a self-ligating bracket was used on one side and a conventional bracket on the other.Materials and Methods:In 43 patients requiring maxillary premolar extraction, a self-ligating bracket (Damon3, SmartClip) was used on the maxillary canine on one side and a conventional bracket (Victory Series) on the other. The teeth were retracted down a 0.018-inch stainless steel archwire, using a medium Sentalloy retraction spring (150 g). The rates of retraction were analyzed using a paired t-test.Results:The mean movement per 28 days for the conventional bracket was 1.17 mm. For the Damon bracket it was 0.9 mm and for the SmartClip bracket it was 1.10 mm. The differences between the conventional and self-ligating brackets were statistically significant: paired t-test, SmartClip, P < .0043; Damon3, P < .0001).Conclusion:The retraction rate is faster with the conventional bracket, probably because of the narrower bracket width of the self-ligating brackets.     

自锁托槽矫治器的特点、分类及应用前景

自锁托槽自问世以来,经历了几十年的发展,目前这种矫治器以其较低的摩擦力、便利的临床操作、患者的舒适度等优势得到了广大正畸医师的青睐.本文对自锁托槽矫治器的特点、分类及临床常用的几种自锁托槽作一综合概述.     

自锁托槽与传统托槽矫治器对牙周健康影响的比较研究

目的 对比戴用自锁托槽与传统托槽矫治器后牙周指数的变化.材料和方法选取12～18岁正畸患者80例,按矫治器类型分为两组：实验组,40例采用AO公司生产的T3自锁托槽矫正的患者;对照组,采用杭州西湖公司生产的徐氏托槽矫正的患者40例.由同一牙周专科医师分别检测80例患者治疗前和治疗6个月的各项牙周指数（GI,PLI,SBI,PD）.结果 治疗6个月后两组间牙周指数（GI,PLI,SBI,PD）差异无显著性.结论 自锁托槽矫治器不会更有利于牙周组织的健康,牙周的健康状况取决于患者的口腔卫生状况.     

Treatment time,outcome, and anchorage loss comparisons of self-ligating and conventional brackets

Objective:To compare the treatment time, outcome, and anchorage loss among orthodontic patients treated by self-ligating brackets (SLBs) and conventional brackets (CBs).Materials and Methods:A retrospective cohort study compared 34 patients (SLB group) treated by SmartClip brackets (3M Unitek, Monrovia, Calif) to 35 patients (CB group) treated by conventional preadjusted Victory series brackets (3M Unitek) and ligated by stainless steel wire ligatures. Pretreatment (T1) and posttreatment (T2) lateral cephalograms were traced and analyzed using Pancherz sagittal-occlusion analysis to obtain skeletal and dental changes in the maxilla and the mandible. The dental cast models were assessed by the Peer Assessment Rating (PAR) Index for the treatment outcomes.Results:The mean treatment time for SLBs (19.19 months) did not show a statistically significant difference from 21.25 months of CBs; the treatment time and pretreatment PAR scores were strongly correlated. There was no difference in anchorage loss between the SLB and CB groups. There were significant dental and skeletal changes among adolescent orthodontic patients regardless of the bracket used. The lingual inclination of the mandibular incisors in the CB group was 3.62° more than in the SLB group (P < .01).Conclusions:The treatment time and anchorage loss are not influenced by the type of bracket used. There are significant dental and skeletal changes among adolescent orthodontic patients regardless of the bracket used. There is significantly greater lingual inclination of mandibular incisors in the CB group than in the SLB group.     

Clinical and microbiological parameters in patients with self-ligating and conventional brackets during early phase of orthodontic treatment

Objective:To determine the effect of different bracket designs (conventional brackets and self-ligating brackets) on periodontal clinical parameters and periodontal pathogens in subgingival plaque.Material and Methods:The following inclusion criteria were used: requirement of orthodontic treatment plan starting with alignment and leveling, good general health, healthy periodontium, no antibiotic therapy in the previous 6 months before the beginning of the study, and no smoking. The study sample totaled 38 patients (13 male, 25 female; mean age, 14.6 ± 2.0 years). Patients were divided into two groups with random distribution of brackets. Recording of clinical parameters was done before the placement of the orthodontic appliance (T0) and at 6 weeks (T1), 12 weeks (T2), and 18 weeks (T3) after full bonding of orthodontic appliances. Periodontal pathogens of subgingival microflora were detected at T3 using a commercially available polymerase chain reaction test (micro-Dent test) that contains probes for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola.Results:There was a statistically significant higher prevalence of A actinomycetemcomitans in patients with conventional brackets than in patients with self-ligating brackets, but there was no statistically significant difference for other putative periodontal pathogens. The two different types of brackets did not show statistically significant differences in periodontal clinical parameters.Conclusion:Bracket design does not seem to have a strong influence on periodontal clinical parameters and periodontal pathogens in subgingival plaque. The correlation between some periodontal pathogens and clinical periodontal parameters was weak.     

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）.     

自锁托槽与传统托槽导致正畸牙根吸收的锥形束CT比较

目的:比较被动自锁托槽与传统直丝弓托槽造成牙根根尖外吸收量的差异,分析被动自锁托槽与牙根吸收的关系.方法:将50例患者随机分为2组,每组25例,分别应用被动自锁托槽或传统直丝弓托槽(0.022系统)进行矫治.治疗前、后拍摄锥形束CT(CBCT),测量上切牙的牙根根尖外吸收量.采用SPSS17.0软件包对2组牙根根尖外吸收量的差异进行t检验.结果:被动自锁托槽和传统直丝弓托槽治疗结束后,上颌切牙牙根吸收量无显著差异(P＞0.05).结论:被动自锁托槽和传统直丝弓托槽都会造成一定量的牙根吸收,但两者造成的牙根根尖外吸收量差异无显著性,不能认为被动自锁托槽会诱发更多的牙根吸收.     

自锁托槽解除上颌牙列拥挤后牙弓与牙齿的三维变化研究

目的 探讨自锁托槽解除牙列拥挤后牙弓与牙齿的三维变化.方法 通过DamonQ自锁托槽系统对16例安氏Ⅰ类中度拥挤患者行不拔牙矫治,在上颌牙列排齐前后分别拍摄CBCT,运用Amira ResolveRT软件进行三维重建并测量牙弓和牙齿的三维变化.结果 运用自锁托槽系统排齐后,上颌的基骨弓宽度、牙槽嵴宽度和牙尖宽度有不同程度的增宽,牙弓前段的增宽量大于牙弓后段;牙槽部的宽度与基骨弓的宽度相关性较高;除第一磨牙外,上颌牙齿均发生不同程度颊倾.结论 在牙弓前段,自锁托槽可能体现出少量基骨弓扩大的效果,越靠近牙弓后段,基骨弓的宽度基本维持;牙槽部宽度的变化以基骨弓的宽度为基础,对于牙槽部较窄的个体,自锁托槽系统可能将通过牙齿的倾斜代偿使牙弓宽度在一定程度上增加.     

Labio-lingual root control of lower anterior teeth and canines obtained by active and passive self-ligating brackets

Objective:To investigate the torque capabilities of passive and active self-ligating (SL) brackets on mandibular incisors and canines using three-dimensional (3D) imaging analysis.Materials and Methods:Two types of SL bracket systems were analyzed: a passive and an active. Both brackets had a 0.022 × 0.028-inch slot size. Treatment protocol and wire sequences were followed as recommended by the manufacturers. Twenty-six patients were included in the passive group and 20 were included in the active group; all received pretreatment and posttreatment cone-beam computed tomography (CBCT) scanning. Based on the CBCT scans, a customized 3D analysis was developed to assess labiolingual inclination of the roots of mandibular canines and incisors with respect to the occlusal plane before and after treatment.Results:Following treatment, a statistically significant labiolingual proclination of the teeth was seen in both groups. Moreover, in both SL systems the roots exhibited a large variation in labiolingual inclination between adjacent teeth even after treatment.Conclusions:A significant proclination was seen for the mandibular front teeth; the claimed third-order torque control of SL systems could not be demonstrated. Therefore, a considerable play between the wire and the brackets could be hypothesized, even more in relation to the passive than the active SL brackets.     

Comparison of root resorption between self-ligating and conventional preadjusted brackets using cone beam computed tomography

Objective:To compare the magnitude of external apical root resorption (EARR) of incisors in patients undergoing the initial phase of orthodontic treatment with two sets of brackets.Materials and Methods:According to the results of the power analysis for sample size calculation, 19 Angle Class I patients (anterior crowding: 3 to 5 mm; mean age: 20.6 years) were included in the study and randomly divided into two groups: group I (n  =  11, self-ligating brackets) and group II (n  =  8, conventional preadjusted brackets). The degree of EARR was detected in 152 upper and lower incisors by using cone-beam computed tomography (CBCT) scans and a three-dimensional program (Dolphin 11.5, Dolphin Imaging & Management Solutions, Chatsworth, Calif) with 25% level of sensitivity. The CBCT scans were obtained before (T1) and 6 months after initiation of treatment (T2). Differences between and within groups were analyzed by nonpaired and paired t-test, respectively, with 5% significance level.Results:Significant differences were found for both groups between T1 and T2. However, no differences in the degree of EARR were detected between the groups studied.Conclusions:Although EARR has occurred in all teeth evaluated, the bracket design (self-ligating or conventional) did not demonstrate any influence on the results observed.     

Comparison of static friction with self-ligating,modified slot design and conventional brackets

Objective

To compare the static frictional forces generated at the bracket/wire interface of stainless steel brackets with different geometries and angulations, combined with orthodontic wires of different diameters.

Material and Methods

The frictional forces were evaluated with three different types of metal brackets: a passive self-ligating (SmartClip^TM, 3M/Unitek, Monrovia, USA), with a modified slot design (Mini Uni Twin^TM, 3M/Unitek, Monrovia, USA) and conventional (Kirium, Abzil, São José do Rio Preto, Brazil). The samples were mounted in a testing device with three different angulations and tested with 0.014" and 0.018" stainless steel wires (American Orthodontics, Sheboygan, USA). The static frictional force was measured using a universal testing machine (DL 500, EMIC^®, São José dos Pinhais, Brazil) with a crosshead speed of 1 mm/min. Statistical analysis was performed by two-way ANOVA followed by Bonferroni''s post hoc test.

Results

There was a significant difference (p<0.05) in static friction when the three types of brackets were tested with the same wire size. The wire diameter influenced friction only when the brackets had a 10º angulation (p<0.05). The angulation influenced friction (p<0.05) when the brackets were associated with a 0.018" wire.

Conclusion

Brackets with a modified slot design showed intermediate static frictional force values between the conventional and self-ligating brackets tested.     

自锁托槽与传统托槽对非拔牙矫治牙弓宽度影响的meta分析

目的:系统评价自锁托槽与传统托槽在非拔牙矫治中牙弓宽度的变化。方法:检索Cochrane Library、ScienceDirect、PubMed、CBM、CNKI、维普全文数据库、万方数据库及Google文献检索,查找自锁托槽与传统托槽对非拔牙矫治牙弓形态影响的临床研究,检索时限从建库截至2013年5月。由2名研究者独立评价纳入研究的质量并提取资料,采用Sata10.0软件对纳入的研究进行meta分析。结果:纳入8项研究,共364例患者。Meta分析结果显示,自锁组与传统组相比,矫治前、后在上颌第一前磨牙区[WMD=0.724,95%CI(0.288,1.160);PU﹤0.01]、下颌第一磨牙区[WMD=0.564,95%CI(0.219,0.909);PL﹤0.01]宽度增加量和上前牙倾斜度增加量有显著差异。结论:现有的临床证据表明,在轻中度拥挤非拔牙矫治中,自锁托槽对上颌第一前磨牙和下颌第一磨牙区的扩弓效果优于传统托槽,且能更好地控制上前牙的倾斜度,但仍需更多高质量的临床研究予以验证。     

A comparison of torque expression between stainless steel,titanium molybdenum alloy,and copper nickel titanium wires in metallic self-ligating brackets

Objective:The force moment providing rotation of the tooth around the x-axis (buccal-lingual) is referred to as torque expression in orthodontic literature. Many factors affect torque expression, including the wire material characteristics. This investigation aims to provide an experimental study into and comparison of the torque expression between wire types.Materials and Methods:With a worm-gear–driven torquing apparatus, wire was torqued while a bracket mounted on a six-axis load cell was engaged. Three 0.019 × 0.0195 inch wire (stainless steel, titanium molybdenum alloy [TMA], copper nickel titanium [CuNiTi]), and three 0.022 inch slot bracket combinations (Damon 3MX, In-Ovation-R, SPEED) were compared.Results:At low twist angles (<12 degrees), the differences in torque expression between wires were not statistically significant. At twist angles over 24 degrees, stainless steel wire yielded 1.5 to 2 times the torque expression of TMA and 2.5 to 3 times that of nickel titanium (NiTi). At high angles of torsion (over 40 degrees) with a stiff wire material, loss of linear torque expression sometimes occurred.Conclusions:Stainless steel has the largest torque expression, followed by TMA and then NiTi.     

2种不同类型自锁托槽对前牙转矩控制的对比研究

摘要：目的比较主动和被动自锁托槽在拔牙病例中对前牙转矩的控制 方法 选取40例拔牙病例,20例应用Empower自锁托槽,20例应用Damon自锁托槽,对治疗前后反应骨性指标的SNA、SNB、ANB、MP-SN和上下前牙倾斜度的牙性指标：UI-SN、U1-PP、U1-NA、L1-NB、L1-MP进行头影测量分析,应用SPSS13.0软件对治疗前后测量的结果进行分析。结果 两组病例治疗前各项测量项目无明显差别;两组病例治疗前后骨性指标无明显改变,而牙性指标UI-SN、U1-PP、U1-NA、L1-NB、L1-MP都有明显减小;Empower组病例治疗后UI-SN、U1-PP、U1-NA测量值较Damon组大,有显著性差异(P<0.05),而Empower组L1-MP治疗后测量值较Damon组小,结果有显著性差异(P<0.05),Empower组L1-NB治疗后测量值较Damon组小,但无明显统计学差别(P>0.05)。结论 主动自锁托槽在拔牙病例中对前牙转矩的控制较被动自锁托槽理想。