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The Angle Orthodontist Jul 2017To analyze the coatings covering esthetic orthodontic wires and the influence of such coatings on bending and frictional properties.
OBJECTIVE
To analyze the coatings covering esthetic orthodontic wires and the influence of such coatings on bending and frictional properties.
MATERIALS AND METHODS
Four commercially available, coated esthetic archwires were evaluated for their cross-sectional dimensions, surface roughness (R), nanomechanical properties (nanohardness, nanoelastic modulus), three-point bending, and static frictional force. Matched, noncoated control wires were also assessed.
RESULTS
One of the coated wires had a similar inner core dimension and elasticity compared to the noncoated control wire, and no significant differences between their static frictional forces were observed. The other coated wires had significantly smaller inner cores and lower elasticity compared to the noncoated wires, and one of them showed less static frictional force than the noncoated wire, while the other two coated wires had greater static frictional force compared to their noncoated controls. The dimension and elastic modulus of the inner cores were positively correlated (r = 0.640), as were frictional force and total cross-sectional (r = 0.761) or inner core (r = 0.709) dimension, elastic modulus (r = 0.777), nanohardness (r = 0.802), and nanoelastic modulus (r = 0.926). The external surfaces of the coated wires were rougher than those of their matched controls, and the R and frictional force were negatively correlated (r = -0.333).
CONCLUSIONS
Orthodontic coated wires with small inner alloy cores withstand less force than expected and may be unsuitable for establishing sufficient tooth movement. The frictional force of coated wires is influenced by total cross-section diameter, inner core diameter, nanohardness, nanoelastic modulus, and elastic modulus.
Topics: Coated Materials, Biocompatible; Dental Alloys; Dental Stress Analysis; Elastic Modulus; Humans; Materials Testing; Orthodontic Appliance Design; Orthodontic Friction; Orthodontic Wires
PubMed: 27731649
DOI: 10.2319/022416-161.1 -
Journal of the World Federation of... Dec 2020Nickel-titanium archwires have unique mechanical properties that make them the archwire of choice during the first phase of orthodontic treatment. However, during its...
BACKGROUND
Nickel-titanium archwires have unique mechanical properties that make them the archwire of choice during the first phase of orthodontic treatment. However, during its clinical use when subjected to oral conditions, these properties can undergo great changes.
MATERIALS AND METHODS
A sample of 24 randomly chosen superelastic NiTi orthodontic archwires (12 TE and 12 PSE) with a 0.014-inch round section from the same manufacturer were distributed into four groups of six archwires each. The first two groups were new wires (as-received), which were used as controls (T0), and the other two were collected after 3 months of clinical usage (as-retrieved) in orthodontic patients (T1). Mechanical properties were measured by mechanical tensile testing and three-point bending tests under the same experimental and temperature conditions (36°C) in a universal testing machine. Comparisons between the groups at T0 and T1 were performed with t-tests and Mann-Whitney U tests. A paired t-test and Wilcoxon signed rank sum test were used for intragroup comparisons (T1-T0).
RESULTS
At baseline, PSE wires presented significantly (P < 0.05) higher load at fracture, range, ultimate tensile strength (UTS), yield strength, springback, maximum tension and flexural ultimate strength (FUS) than those of TE wires. At T1, a significant decrease in load at fracture and UTS in PSE wires and in FUS in TE wires was found. After 3 months of clinical usage, the changes (T1-T0) in the mechanical properties of both alloys were similar.
CONCLUSIONS
After 3 months of clinical usage, wires lost some of their mechanical properties and had less resistance to breakage. However, the as-received differences between both wires were maintained after clinical usage.
Topics: Alloys; Elasticity; Humans; Materials Testing; Nickel; Orthodontic Wires; Titanium
PubMed: 33168487
DOI: 10.1016/j.ejwf.2020.10.001 -
Dental Press Journal of Orthodontics 2018To identify the appropriate power level for electric welding of three commercial brands of nickel-titanium (NiTi) wires.
OBJECTIVE
To identify the appropriate power level for electric welding of three commercial brands of nickel-titanium (NiTi) wires.
METHODS
Ninety pairs of 0.018-in and 0.017 × 0.025-in NiTi wires were divided into three groups according to their manufacturers - GI (Orthometric, Marília, Brazil), GII (3M OralCare, St. Paul, CA) and GIII (GAC,York, PA) - and welded by electrical resistance. Each group was divided into subgroups of 5 pairs of wires, in which welding was done with different power levels. In GI and GII, power levels of 2.5, 3, 3.5, 4, 4.5 and 5 were used, while in GIII 2.5, 3, 3.5 and 4 were used (each unit of power of the welding machine representing 500W). The pairs of welded wires underwent a tensile strength test on an universal testing machine until rupture and the maximum forces were recorded. Analysis of variance (ANOVA) and post-hoc tests were conducted to determine which subgroup within each brand group had the greatest resistance to rupture.
RESULTS
The 2.5 power exhibited the lowest resistance to rupture in all groups (43.75N for GI, 28.41N for GII and 47.57N for GIII) while the 4.0 power provided the highest resistance in GI and GII (97.90N and 99.61N, respectively), while in GIII (79.28N) the highest resistance was achieved with a 3.5 power welding.
CONCLUSIONS
The most appropriate power for welding varied for each brand, being 4.0 for Orthometric and 3M, and 3.5 for GAC NiTi wires.
Topics: Dental Alloys; Dental Stress Analysis; Humans; Materials Testing; Nickel; Orthodontic Wires; Tensile Strength; Titanium; Welding
PubMed: 30088566
DOI: 10.1590/2177-6709.22.3.058-062.oar -
Romanian Journal of Morphology and... 2020The fixed orthodontic measures taken induce significant stress to the gingival growth process during arch wire maneuvers of aligning and leveling. We observed, for a...
The fixed orthodontic measures taken induce significant stress to the gingival growth process during arch wire maneuvers of aligning and leveling. We observed, for a period of one to four years, fixed orthodontic devices in 80 human subjects. From these, we selected 44 subjects (22 women and 22 men) where the inflammatory process exhibited following the orthodontic fixed treatment, and with vacuum-formed orthodontic retainers (VFR) succeeding to fixed treatment. Samples were collected from each patient and histological and immunohistochemical (IHC) methodology was made to analyze the cytoarchitecture. Statistics were made after one-way analysis of variance (ANOVA), with the Bonferroni's correction. The IHC examination performed in the early stage revealed the presence in the inflammatory infiltrate of CD8-type T-lymphocytes, and of dendritic cells in large numbers. The examination performed in the late stage revealed the presence in the inflammatory infiltrate of CD20-type B-lymphocytes, which are mature cells capable of immunoglobulin synthesis, their activation being an important step in the maturation of the antibody response. The stress generated by arch wires in both genders was significantly higher than in the case of VFR. This observation was pointed out also by the cytohistological investigation outcome but was also based on an original scale conceived by our research team, following gingival hyperplasia evaluation. Also, with statistical significance, the comparative obtained values for men (p=0.01) and for women (p=0.001) illustrate clinical observations, allowing to affirm that, in our case, men were more stressed in bearing arch wire devices (AWD) and VFR, in comparison with women.
Topics: Analysis of Variance; Female; Gingiva; Humans; Male; Orthodontic Appliance Design; Orthodontic Retainers; Orthodontic Wires; Orthodontics, Corrective; Vacuum
PubMed: 34171076
DOI: 10.47162/RJME.61.4.29 -
Current Osteoporosis Reports Aug 2018Gentle and continuous loads are preferred for optimum orthodontic tooth movement. Nitinol, an alloy of nickel and titanium developed for the aerospace industry, found... (Review)
Review
Review of Superelastic Differential Force Archwires for Producing Ideal Orthodontic Forces: an Advanced Technology Potentially Applicable to Orthognathic Surgery and Orthopedics.
PURPOSE OF REVIEW
Gentle and continuous loads are preferred for optimum orthodontic tooth movement. Nitinol, an alloy of nickel and titanium developed for the aerospace industry, found its first clinical applications in orthodontics because it has ideal load-deflection behavior. The purpose of this review is to elucidate the criteria for effective orthodontic mechanics relative to emerging Nitinol technology. The specialized materials with variable stiffness that were originally developed for orthodontics are increasingly attractive for in the temporomandibular joint, orthognathic surgery, and orthopedics.
RECENT FINDINGS
The evolution of orthodontic archwires is driven by a need to achieve low load-deflection characteristics and Nitinol is the alloy of choice. Scientific knowledge of the biological response to orthodontic forces continues to grow, but definitive guidance on optimal force levels for individual teeth is elusive. Finite element models (FEM) that take into account periodontal ligament (PDL) stresses indicate differential force archwires are needed to realize optimal treatment. However, previous wire fabrication methods, including welding of different materials and selective resistive heating, are limited by poor mechanical performance and spatial resolution. Recently, a novel laser processing technique was developed for precisely programing relative levels of stiffness in a single archwire. FEM was used to estimate the optimal force for each tooth by calculating the 3D bone-PDL surface area. There remains a general consensus that light and continuous forces are desirable for orthodontic treatment. New developments in archwire materials and technology have provided the orthodontist with a complete spectrum of load-deflection rates and differential force options to express these forces with maximized archwire economy. These technologies also appear to have application to orthopedic implant devices.
Topics: Alloys; Elasticity; Finite Element Analysis; Humans; Lasers; Materials Science; Orthodontic Wires; Orthognathic Surgical Procedures; Orthopedic Procedures; Pliability; Temporomandibular Joint
PubMed: 29926347
DOI: 10.1007/s11914-018-0457-5 -
Dental Materials Journal Dec 2019Corrosion of metallic materials in the oral cavity could trigger metal allergy in patients. To clarify the risk elevation of magnetic fields (MFs) exposure on metallic...
Corrosion of metallic materials in the oral cavity could trigger metal allergy in patients. To clarify the risk elevation of magnetic fields (MFs) exposure on metallic corrosion when combined with fluoride-containing dental care products and indigenous oral bacteria, we investigated electric toothbrush-derived MF-induced corrosion of orthodontic stainless steel (SUS) and nickel titanium (Ni-Ti) wires in the presence of fluoride and oral bacteria, i.e. Streptococcus (S) mutans and S. sanguinis. MFs induced an electric current in the wires under both environments. Oral bacteria corroded SUS wires, and fluoride corroded SUS and Ni-Ti wires as previously reported; however, no additive or synergistic effects of MF exposure on fluoride- and microbiologically-induced metallic corrosion were observed. These results suggest that the MFs from electric toothbrushes do not increase the risk of corrosion of metallic appliances, given that the oral environment of patients is exposed to oral bacteria and fluoride-containing products.
Topics: Bacteria; Corrosion; Dental Alloys; Fluorides; Humans; Magnetic Fields; Materials Testing; Orthodontic Wires; Surface Properties; Titanium
PubMed: 31366769
DOI: 10.4012/dmj.2018-293 -
Journal of the Formosan Medical... Jan 2018The application of an appropriate force system is indispensable for successful orthodontic treatments. Second-order moment control is especially important in many...
BACKGROUND/PURPOSE
The application of an appropriate force system is indispensable for successful orthodontic treatments. Second-order moment control is especially important in many clinical situations, so we developed a new force system composed of a straight orthodontic wire and two crimpable hooks of different lengths to produce the second-order moment. The objective of this study was to evaluate this new force system and determine an optimum condition that could be used in clinics.
METHODS
We built a premolar extraction model with two teeth according to the concept of a modified orthodontic simulator. This system was activated by applying contractile force from two hooks that generated second-order moment and force. The experimental device incorporated two sensors, and forces and moments were measured along six axes. We changed the contractile force and hook length to elucidate their effects. Three types of commercial wires were tested.
RESULTS
The second-order moment was greater on the longer hook side of the model. Vertical force balanced the difference in moments between the two teeth. Greater contractile force generated a greater second-order moment, which reached a limit of 150 g. Excessive contractile force induced more undesired reactions in the other direction. Longer hooks induced greater moment generation, reaching their limit at 10 mm in length.
CONCLUSION
The system acted similar to an off-center V-bend and can be applied in clinical practice as an unconventional loop design. We suggest that this force system has the potential for second-order moment control in clinical applications.
Topics: Bicuspid; Biomechanical Phenomena; Dental Stress Analysis; Humans; Orthodontic Brackets; Orthodontic Space Closure; Orthodontic Wires; Stress, Mechanical; Tooth Movement Techniques
PubMed: 28408197
DOI: 10.1016/j.jfma.2017.03.002 -
Brazilian Dental Journal 2022A new device was developed to enable the visualization and measurement of canine angulation while at the same time visualizing and measuring the force transmitted to...
A new device was developed to enable the visualization and measurement of canine angulation while at the same time visualizing and measuring the force transmitted to adjacent teeth. This study aimed to evaluate the mesiodistal tilt angle of the upper canine brackets, the wire deflection, and its effects on adjacent teeth with five different slot designs of upper canines. Wires (0.020" and 0.019" x 0.025") were tested on different five bracket types at five different distal angles. The force applied to adjacent teeth was measured as the angle was increased, and its consequences were observed in the posterior and anterior regions as well. The force tension (gf) was measured in a universal testing machine. Data were submitted to a 3-way ANOVA and Tukey's test (α=0.05). For both arches, regardless of the type of tooth and bracket type, the highest means tension mean values were shown by the 20° angle, followed by the 15°,10°, and 5° angles, which differed statistically among themselves. Overall, for 5°, 10°, and 15° angles, conventional and versatile brackets showed significantly higher force values in all teeth, tip-edge and control brackets showed the lowest. The highest force values were observed in central and lateral incisors with conventional and versatile brackets and on first and second premolar teeth with self-ligating passive and control brackets. Conventional brackets presented the highest forces, tip-edge and control brackets showed the lowest. The teeth that suffered the greatest forces were lateral incisors, and those that suffered the least were second premolars.
Topics: Orthodontic Wires; Orthodontic Appliance Design; Orthodontic Brackets; Stainless Steel; Friction; Dental Stress Analysis; Materials Testing
PubMed: 36287499
DOI: 10.1590/0103-6440202205104 -
The Angle Orthodontist Jul 2018To evaluate the esthetics and frictional force of an orthodontic wire passed through a newly designed tube made of a polyether ether ketone (PEEK) resin.
OBJECTIVES
To evaluate the esthetics and frictional force of an orthodontic wire passed through a newly designed tube made of a polyether ether ketone (PEEK) resin.
MATERIALS AND METHODS
Two types of standard PEEK tubes were prepared at 0.5 × 0.6ф and 0.8 × 0.9ф, and different archwires were passed through the tubes. Color values were determined according to brightness and hues. Friction was assessed with different bracket-wire combinations, and surface roughness was determined by stereomicroscopy before and after the application of friction.
RESULTS
The PEEK tube showed a color difference that was almost identical to that of coated wires conventionally used in clinical practice, indicating a sufficient esthetic property. The result of the friction test showed that the frictional force was greatly reduced by passing the archwire through the PEEK tube in almost all of the archwires tested.
CONCLUSIONS
Use of the new PEEK tube demonstrated a good combination of esthetic and functional properties for use in orthodontic appliances.
Topics: Benzophenones; Color; Esthetics, Dental; Friction; Ketones; Orthodontic Wires; Polyethylene Glycols; Polymers; Surface Properties
PubMed: 29561658
DOI: 10.2319/082417-572.1 -
IEEE Transactions on Bio-medical... Jul 2020This study investigated the performance of a dynamic orthodontic moment prediction model by analyzing orthodontic treatment processes with different utility archwires.
OBJECTIVE
This study investigated the performance of a dynamic orthodontic moment prediction model by analyzing orthodontic treatment processes with different utility archwires.
METHOD
The prediction model was based on a wax resistance model, the combined load theory of beams and the lateral buckling theory of prisms. The experimental samples used herein comprised 12 different archwire configurations (3 different materials and 4 different diameters). The utility archwire was ligated to the 11th tooth of the wax mold, which was immersed in a constant temperature water environment at 75 °C for 2 min.
RESULT
As the archwire diameter increased, increasing the elastic modulus of the archwire produced greater increases in the change rate of the orthodontic moment with respect to the lateral arc length. A comparison of the orthodontic moment values from three common orthodontic archwire materials revealed the following trend: stainless steel wire > Australian wire > Ni-Ti wire.
CONCLUSION
The accuracy of the utility archwire dynamic orthodontic moment prediction model was verified through a comparison of the experimental measurements and theoretical calculations.
SIGNIFICANCE
The presented model can help make timely adjustments to orthodontic treatment schemes, improve the orthodontic effect, shorten the treatment cycle, and provide reference and guidance that enables orthodontists to carry out orthodontic treatment safely and efficiently.
Topics: Australia; Materials Testing; Orthodontic Appliance Design; Orthodontic Brackets; Orthodontic Wires; Stainless Steel; Surface Properties; Titanium
PubMed: 31725367
DOI: 10.1109/TBME.2019.2953135