Types Of Orthodontic Archwires Research Articles

Electroanalysis of nickel ions released in artificial saliva from three orthodontic arch wires: Stainless Steel (SS), NiTi, and CuNiTi

Background: Nickel titanium wires are superior for first alignment because they have exceptional shape memory and super-elasticity. Increased concerns have been raised about the high rate of nickel (Ni) allergy and the growing usage of dental biomaterials that contain Ni. Aim: The aim of the study was to analyze and evaluate the rate of nickel release from different types of orthodontic arch wires. Materials and methods: A set of arch wires of nickel titanium (NiTi), SS and Cu-NiTi were immersed in artificial saliva for three days and analyzed after three days. The amount of Ni ions released from the sample were evaluated using electrochemical techniques such as Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and polarization (Tafel) plot. Results: The EIS and Tafel graph confirmed the s-NiTi, s-CuNiTi showed an excellent corrosion resistance than the s-SS. From all the above measurements, we can conclude that the saliva can affect the corrosion resistance property of the SS, NiTi, CuNiTi day by day. Conclusion: From this study it was concluded that the saliva can affect the corrosion resistance property of the SS, NiTi, CuNiTi day by day, and there was nickel ion release but at a very negligible rate.

Effects of Laser Application on Leveling Efficiency Using Different Orthodontic Archwires

Purpose: to evaluate the effect of low level laser on leveling and alignment by using two types of orthodontic archwires. Materials and methods: A consecutive sample of 32 patients requiring fixed orthodontic appliances were grouped into four groups: laser group with 0.014 inch copper NiTi wire, laser group with 0.014 inch superelastic NiTi wire, 0.014 inch copper NiTi wire group without laser, 0.014 inch superelastic NiTi wire group without laser. Directly after the first arch wire insertion the investment group received a LLLT dose (laser application group of patients). The LLLT device was adjusted to 635 nm wavelength and with 2.2 J/point (energy dosage). There were four points of application regarding each mandibular incisor’s root, two of them are buccal and the other two points are palatal. This laser dosage was applied repeatedly on 7, 14 and 28 days for each patient in the laser group. The evaluation of alignment by studying four casts taken along the initial stage of treatment (before treatment T0, Two weeks T1, four weeks T2 and six weeks T3 of treatment). Results: Statistical analysis between the groups revealed that there was no statistically significant difference between the four groups at four different intervals (T0-T1), (T1-T1), (T2-T3) and (T0-T3) (P-value = 0.813, 0.601, 0.646, 0.340) respectively. Conclusion: The two forms of NiTi wires (superelastic NiTi wire and Cu NiTi wire) during the alignment process in the initial stage of the treatment were the same regarding the efficiency of alignment, either with or without laser application, and for the acceleration of the tooth movement in orthodontics the application of LLLT wasn’t effective during the initial aligning stage of orthodontic treatment either with superelasti NiTi wire or Cu NiTi wire.

Impact of Simulated Gastric Acid on Surface Roughness and Frictional Resistance of Orthodontic Archwires: An In vitro Study

Introduction: Acid regurgitation caused by gastro-oesophageal reflux disease can lead to decreases in intraoral pH below the critical pH for orthodontic appliances. Exposure of brackets and archwires to such acidic environments causes changes in the surface properties that affect the frictional forces generated during orthodontic sliding mechanics and reduce the clinical efficacy of the wires. Aim: This in vitro study aimed to determine the effects of simulated gastric acid with pH 1.2 and pH 4 on the surface topography, surface roughness, and frictional resistance properties of different types of orthodontic archwires. Materials and Methods: A comparative in vitro study evaluated a total of 135 samples of three commercially available archwires: Stainless Steel (SS), nickel titanium, and beta-titanium (n=45/group). Each archwire was divided into three subgroups (n=15) according to different pH solutions: distilled water (control; pH 6.7), pH 4, and pH 1.2. The samples in the two acidic pH subgroups were immersed in the respective solution for two minutes, rinsed with distilled water, and stored in distilled water at 37°C. The procedure was repeated 6 times a day for nine days with 24-hours interval in between each cycle. The surface topography of the wires was examined by scanning electron microscopy, while the surface roughness was inspected by noncontact surface profilometry. Finally, the frictional resistance was measured by a universal testing machine. One-way ANOVA and a Tukey’s post-hoc test were used for analysis, with values of p≤0.05 considered significant. Results: The results showed an increase in surface roughness of the SS (p<0.001) and beta-titanium (p=0.003) wires as the acidity of the solution increased. The SS wires showed the lowest frictional resistance in pH 1.2 solution among the wires used (p=0.005). No correlation was found between surface roughness and frictional resistance in this study. Conclusion: Increased acidity condition significantly affects the surface roughness of beta-titanium and SS wires, and has no effect on the frictional behaviour of the orthodontic wires expects in the SS wires. Thus, because the surface properties of the archwires can be affected by acidity in the oral cavity, it is recommended to change the orthodontic wires regularly throughout orthodontic treatment, especially in patients with gastro-oesophageal reflux disease.

The Effect of Fluoride on Beta-Titanium Orthodontic Wire's Surface Texture and Friction Resistance

Objectives: The aim of this study is to investigate the effect of fluoride application on the surface properties and frictional resistance of two types of orthodontic archwires. Materials and Methods: A total of sixty stainless-steel, and beta-titanium orthodontic archwires in-addition to fifty ceramic brackets were examined in-vitro and in-situ. The friction resistance of all wires with ceramic brackets before/after topical fluoride application were examined in-vitro and in-situ. Moreover, surface properties of the tested wires before/after fluoride application and before/after friction test were examined by scanning electron microscope (SEM). Paired t-test and Dunnett t-test were used to compare frictional resistance of the stainless-steel wires to the beta titanium wires as-received, in-vitro and in-situ (p≤ 0.05). Results: Beta-titanium wires recorded significant high friction resistance when compared to stainless-steel wires. Fluoride application did not significantly affect the friction resistance of the tested wires. SEM observation revealed the roughness of as-received beta-titanium wires and the deterioration of its surface texture after fluoride application in-vitro and in-situ. Conclusion: Beta-titanium wires recorded high friction resistance when compared to stainlesssteel wires under the as- received, in-vitro and in-situ conditions, moreover, fluoride application did not affect friction resistance of beta-titanium wires while it affected its surface properties.

Effects of clinical use and sterilization on surface topography and surface roughness of three commonly used types of orthodontic archwires.

To evaluate the changes in surface topography and roughness of stainless steel (SS), nickel-titanium and beta-titanium (β-Ti) archwires after clinical use and sterilization. Thirty wires each of SS, nitinol, and β-Ti (3M Unitek) were tested in as received, as received and autoclaved, and clinically retrieved then autoclaved conditions. A sterilization protocol of 134°C for 18 min was performed using an autoclave. Surface topography of specimens from each subgroup was examined using an environmental scanning electron microscope (ESEM model Quanta 200, The Netherlands) at ×100, ×1000, and ×2500 magnifications. Surface roughness was measured using arithmetic mean roughness (Ra) values obtained from optical profilometric scanning (Taylor Hobson, Leicester, UK). Data were analyzed by one-way analysis of variance and Tukey's post-hoc procedures. Scanning electron microscope images revealed an increase in surface irregularities in SS and nitinol wires after clinical use. There was a significant increase in Ra values of SS orthodontic wires after intra-oral exposure (P = 0.0002). Surface roughness of SS wires increased significantly after clinical use. Autoclave sterilization did not affect considerably on surface characteristics of any archwire.

GALVANIC CORROSION AMONG DIFFERENT COMBINATION OF ORTHODONTIC ARCHWIRES AND STAINLESS STEEL BRACKETS

Introduction: The aim of this study was to assess the galvanic behavior of different bracket and archwire combinations that are commonly used in orthodontic treatments. Methods: Three types of orthodontic archwires with a diameter of 0.016×0.022 inch and 80 standard edgewise maxillary central incisor brackets were selected. Three groups consisted of different wire-bracket couples and one group was just brackets as a control group. Each group had five samples. Four brackets were then connected to each wire by elastic bands made from electrochemically neutral material. The samples were immersed into capped containers of Fusayama-Meyer artificial saliva. After six weeks, the released nickel ions were quantified via ion absorption technique. The mean and the standard deviation of all four groups were calculated and the data were compared together with Kruskal-Wallis non-parametric statistical test. Results: The highest concentration of released nickel ions was for bracket+ steel archwire and the least for the bracket without archwire. Conclusion: There were not significant differences among experimental groups, so it could be concluded that galvanic corrosion would not be a serious consideration through orthodontic treatment.

Mechanical properties of coated superelastic archwires in conventional and self-ligating orthodontic brackets

Coated archwires have been introduced to improve esthetics during orthodontic treatment. Our aim was to investigate the mechanical properties of coated superelastic archwires compared with conventional superelastic archwires with conventional and self-ligating brackets. Four types of orthodontic archwires were investigated, 2 superelastic nickel-titanium and 2 coated Ultraesthetic archwires in 0.016-in and 0.018 x 0.025-in dimensions (all from G&H Wire, Greenwood, Ind). To achieve the same nominal size, the coated archwire is constructed from a smaller archwire that, when coated, reaches the nominal dimensions stated for the archwire. Conventional edgewise Orthos and Damon 2 self-ligating brackets (both from Ormco, Orange, Calif) were used with each wire. All specimens were tested in a universal testing machine in a 3-point bending test at a speed of 1 mm per minute and deflected for 2 mm. Loading and unloading forces were recorded and load-deflection curves plotted. Coated superelastic wires produced statistically significantly lower forces in loading and unloading when compared with the superelastic nickel-titanium wires at most archwire deflections (P <0.01). For nickel-titanium wires, loading values ranged from 189 to 1202 g, whereas the respective values for coated wires were 124 to 772 g. For all wires, an increase in size resulted in an increase in force. Interactions between wire type (coated or uncoated) and bracket type were observed. Ultraesthetic coated archwires produced lower force values in loading and unloading compared with uncoated wires of same nominal size. The Damon 2 self-ligating bracket system produced lower force values in loading and unloading. The lowest forces were generated by the combination of Ultraesthetic coated archwires and Damon 2 self-ligating brackets.

Evaluation of The Effect of Immersion Periods in The Artificial Saliva on The Surface Roughness of Three Types of orthodontic Arch Wires

Aims: To evaluate the effect of immersion periods in artificial saliva on the surface roughness of an arch wire. Materials and Methods: The roughness of three types of orthodontic arch wires: stainless steel (SS), titanium molybdenum alloy (TMA) and composite coated wire (CC) were first measured at dry condition then incubated in artificial saliva at 37 o C with saliva pH (7.25) for different immersion periods (1, 14 and 28 days). Then the surface roughness was measured by using Taylor Hobson Profi-lometer (Talysurf type 10). Results: There was a significant increase in surface roughness of the three types of wires during the first day of immersion but as the immersion periods increased, it showed a non significant difference in the roughness of SS and TMA. The roughness of CC however, increased. Conclusions: It was concluded that the surface roughness of SS and TMA wires increased during the first day of immersion, such increase is not significant after that, while in case of CC, as the immersion periods increase the surface roughness significantly increased.

Comparison between Force Deflection Values of Different Types of Orthodontic Arch Wires.

Aims: To evaluate the force values of different types of arch wires. Materials and Methods: Five types of arch wires used. The sample consisted of 150 wires specimens divided into three deflections (1 mm, 2mm and 3 mm). A universal tensile testing machine with the use of special designed fixture was used to perform Three Point Bending Test and the force value related to gram (gm) was measured during loading (activation) of the wire to 1 mm, 2 mm or 3 mm deflections. Results: The results of this investigation showed a significant difference (P≤ 0.05) in force values among all arch wires. Conclusions: The conclusions of this study showed that the solid stainless steel wires provided a heavy force, while the multistranded gave rise to the lowest force value.

Influência do Tipo de Fio Ortodôntico e da Angulação de Segunda Ordem sobre as Forças de Fricção

This study evaluated static and kinetic friction generated by four types of orthodontic arch wires: Stainless steel (Stainless Steel, Ormco), β-Titanium (TMA, Ormco), Nickel Titanium (Ni-Ti, Ormco), and ion implanted β- Titanium (TMA Low friction, Ormco) at three different second order angulations (0°, 4° and 8). The arch wires (0.019 × 0.025 inch) were drawn through 0.022-in slot stainless steel brackets (Mini-Diamond, Ormco) fixed on acrylic cylinders mounted on a specially designed apparatus. Friction was measured using an Instrom universal testing machine. Data was analysed by a 3 × 4 factorial Anova followed by Student Neuman-Keuls comparison of means. Static and kinetic friction were significantly affected (p<0.0001) by both second order angulation and arch wire type. With increasing angulation, friction increased for all arch wire types. At 0° angulation, Stainless Steel arch wires produced significantly lower static friction than the TMA arch wires. At the 4° angulation, both the TMA Low Friction and Ni-Ti arch wires produced lower levels of static and kinetic friction than the Stainless Steel and TMA arch wires. At the 8° angulation, Ni-Ti arch wires produced the lowest values of static and kinetic friction. Conclusion(1) When second-order angulation was increased, friction increased for all bracket types. (2) Stainless steel wires reduced static friction only in the passive state. (3) The nickel titanium arch wires produced lower levels of friction at higher angulations. (4) Ion implantation of arch wires is an effective way of reducing friction