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BMC Oral Health Sep 2022The T-loop has been used clinically to close gap between teeth. And it is a typical orthodontic archwire bending method. However, the design of the T-loop parameters for...
BACKGROUND
The T-loop has been used clinically to close gap between teeth. And it is a typical orthodontic archwire bending method. However, the design of the T-loop parameters for different patients is based on the clinical experience of the dentists. The variation in dentists' clinical experience is the main reason for inadequate orthodontic treatment, even high incidence of postoperative complications.
METHODS
Firstly, the tooth movement prediction model is established based on the analysis of the T-loop structure and the waxy model dynamic resistance. As well as the reverse reconstruction of the complete maxillary 3D model based on the patient CBCT images, the oral biomechanical FEM analysis is completed. A maxillary waxy dental model is manufactured to realize the water-bath measurement experiment in vitro mimicking the oral bio-environment. Thus, the calculated, simulation and experimental data are obtained, as well as obtaining a cloud of total deformation from the simulation analysis.
RESULTS
The growth trend of the 11 sets of simulation data is the same as that of the experimental data. And all of them show that the tooth displacement is positively correlated with the cross-sectional size of the archwire, and the clearance distance. As well as the higher Young's modulus of the archwire material, the greater the tooth displacement. And the effect of archwire parameters on tooth displacement derived from simulation and experimental data is consistent with the prediction model. The experimental and calculated data are also compared and analyzed, and the two kinds of data are basically consistent in terms of growth trends and fluctuations, with deviation rates ranging from 2.17 to 10.00%.
CONCLUSIONS
This study shows that the accuracy and reliability of the tooth movement prediction model can be verified through the comparative analysis and deviation calculation of the obtained calculated, simulation and experimental data, which can assist dentists to safely and efficiently perform orthodontic treatment on patients. And the FEM analysis can achieve predictability of orthodontic treatment results.
Topics: Cross-Sectional Studies; Humans; Orthodontic Wires; Reproducibility of Results; Tooth Movement Techniques; Water
PubMed: 36115965
DOI: 10.1186/s12903-022-02430-9 -
International Orthodontics Mar 2017In sliding mechanics, frictional force is an important counter-balancing element to orthodontic tooth movement, which must be controlled in order to allow application of... (Comparative Study)
Comparative Study
In sliding mechanics, frictional force is an important counter-balancing element to orthodontic tooth movement, which must be controlled in order to allow application of light continuous forces. The purpose of this study was to compare the frictional forces between a stainless steel bracket and five different wire alloys under dry and wet (artificial saliva) conditions. TiNi, TiNiCu, TiNiCo, commercial wires A and commercial wires B with equal dimensions of 0.016×0.022'' were tested in this experiment. The stainless steel bracket was chosen with a slot dimension of 0.022''. Micro-hardness of the wires was measured by the Vickers micro-hardness test. Surface topography of wires was measured by an optical microscope and quantified using surface roughness testing. Static and kinetic friction forces were measured using a custom-designed apparatus, with a 3-mm stretch of wire alloy at a crosshead speed of 1mm/min. The static and dynamic frictions in the wet condition tended to decrease more slowly than those in the dry condition. Therefore, the friction of TiNiCu and commercial wires B would increase. Moreover, these results were associated with scarred surfaces, i.e. the increase in friction would result in a larger bracket microfracture. From the results, it is seen that copper addition resulted in an increase in friction under both wet and dry conditions. However, the friction in the wet condition was less than that in dry condition due to the lubricating effect of artificial saliva.
Topics: Cobalt; Copper; Dental Alloys; Hardness; Humans; Nickel; Orthodontic Brackets; Orthodontic Friction; Orthodontic Wires; Saliva, Artificial; Stainless Steel; Titanium
PubMed: 28162971
DOI: 10.1016/j.ortho.2016.12.017 -
The Angle Orthodontist Jan 2019To compare the flexural properties of rectangular nickel-titanium (Ni-Ti) orthodontic wires in occlusoapical and faciolingual orientations using a standardized test...
OBJECTIVE
To compare the flexural properties of rectangular nickel-titanium (Ni-Ti) orthodontic wires in occlusoapical and faciolingual orientations using a standardized test method.
MATERIALS AND METHODS
Twenty-two rectangular Ni-Ti wire groups were tested in occlusoapical (ribbon) orientation: eight conventional Ni-Ti products, five superelastic Ni-Ti products, and nine thermal Ni-Ti products (n = 10 per group). Six products of thermal Ni-Ti wire were tested in faciolingual (edgewise) orientation. A three-point bending test was performed to measure deactivation force at 3.0-, 2.0-, 1.0-, and 0.5-mm deflections of each rectangular wire at 37.0 ± 0.5°C. Analysis of variance and post hoc Student-Newman-Keuls tests were used to compare the mean values of the different groups (α = .05).
RESULTS
The ranges of deactivation forces varied greatly with different kinds, sizes, products, and deflections of Ni-Ti wires. One product of conventional and superelastic Ni-Ti wires had steeper force-deflection curves. Four products had similarly shaped flat force-deflection curves, whereas the sixth product had a moderately steep force-deflection curve. Thermal Ni-Ti wires had smaller deactivation forces ranging from 0.773 N (78.8 g) to 2.475 N (252.4 g) between deflections of 1.0 and 0.5 mm, whereas wider ranges of force from 3.371 N (343.7 g) to 9.343 N (952.7 g) were predominantly found among conventional Ni-Ti wires between deflections of 3.0 and 2.0 mm.
CONCLUSIONS
Clinicians should critically select archwires for use in the occlusoapical orientation not only based on Ni-Ti wire type, size (0.022 × 0.016-in or 0.025 × 0.017-in), and product but also with deactivation deflections from 0.5 and 1.0 mm to obtain light forces in the occlusoapical orientation.
Topics: Dental Alloys; Dental Stress Analysis; Elasticity; Flexural Strength; Humans; Materials Testing; Nickel; Orthodontic Wires; Titanium
PubMed: 30080130
DOI: 10.2319/021717-118.1 -
Dental Press Journal of Orthodontics 2021This paper aims to verify the thermodynamic, mechanical and chemical properties of CuNiTi 35ºC commercial wires.
OBJECTIVE
This paper aims to verify the thermodynamic, mechanical and chemical properties of CuNiTi 35ºC commercial wires.
METHODS
Forty pre-contoured copper-nickel-titanium thermodynamic 0.017 x 0.025-in archwires with an Af temperature of 35°C were used. Eight wires from five different manufacturers (American Orthodontics® [G1], Eurodonto® [G2], Morelli® [G3], Ormco® [G4] and Orthometric® [G5]) underwent cross-sectional dimension measurements, tensile tests, SEM-EDS and differential scanning calorimetry (DSC) tests. Parametric tests (One-way ANOVA and Tukey post-test) were used, with a significance level of 5%, and Pearson's correlation coefficient test was performed between the Af and chemical elements of the wires. All sample tests and statistical analyses were double-blinded.
RESULTS
All wires presented standard dimensions (0.017 x 0.025-in) and superelastic behavior, with mean plateau forces of: G1 = 36.49N; G2 = 27.34N; G3 = 19.24 N; G4 = 37.54 N; and G5 = 17.87N. The Af means were: G1 = 29.40°C, G2 = 29.13°C and G3 = 31.43°C, with p>0.05 relative to each other. G4 (32.77°C) and G5 (35.17°C) presented statistically significant differences between each other and among the other groups. All samples presented Ni, Ti, Cu and Al in different concentrations.
CONCLUSIONS
The chemical concentration of the elements that compose the alloy significantly influenced the thermodynamic and mechanical properties.
Topics: Cross-Sectional Studies; Dental Alloys; Elasticity; Materials Testing; Orthodontic Wires; Stress, Mechanical; Titanium
PubMed: 34008740
DOI: 10.1590/2177-6709.26.2.e211945.oar -
L' Orthodontie Francaise Jun 2022Plaque control remains a concern in oral health but also in orthodontics.
INTRODUCTION
Plaque control remains a concern in oral health but also in orthodontics.
OBJECTIVE
The aim of this paper was to investigate the dental plaque adhesion to different orthodontic appliances.
MATERIALS AND METHODS
Four literature reviews were initiated to clarify the accumulation of dental plaque to different orthodontic appliances, namely the type of brackets (conventional versus self-ligating, metal versus clear), the type of ligatures (metal versus elastomeric) in addition to the type of archwires. Moreover, a gallery of Scanning Electron Microscopy (SEM) images was made on different orthodontic appliances before and/or after time in the oral cavity.
RESULTS
Considering the strong methodological heterogeneity of the included studies, there is no consensus on which type of bracket should be preferred for the prevention of plaque retention. Metal ligatures would be less prone to plaque accumulation compared to elastomeric ligatures, which are themselves color-dependent. The type of archwire was not investigated in this topic. SEM images highlighted the presence of anfractuosities on the surface of new orthodontic archwires as well as the presence of biofilm at different degrees of maturation on the appliances after time in the oral cavity.
CONCLUSION
Although it is not possible to establish a consensus on which orthodontic appliances should be preferred to decrease plaque retention, different stages of biofilm evolution are observable on their surface and therefore potentially associated with a proportional virulence.
Topics: Biofilms; Dental Alloys; Dental Plaque; Elastomers; Humans; Microscopy, Electron, Scanning; Orthodontic Appliance Design; Orthodontic Brackets; Orthodontic Wires; Stainless Steel
PubMed: 35818281
DOI: 10.1684/orthodfr.2022.74 -
International Orthodontics Jun 2021The present study was performed to affirm surface characterization, as well as to compare the effect of coating of stainless-steel (SS) orthodontic brackets and wires by... (Comparative Study)
Comparative Study
OBJECTIVE
The present study was performed to affirm surface characterization, as well as to compare the effect of coating of stainless-steel (SS) orthodontic brackets and wires by nanoparticles Chitosan (CTS) or Zinc oxide (ZnO) during friction.
MATERIAL AND METHODS
Seventy SS brackets for the upper right central incisors with a 0.022-inch system and seventy 0.019×0.025-inch SS rectangular wires, with and without ZnO and CTS nanoparticle coating, were used. Coating was analysed by SEM. A universal testing machine was used to calculate the friction between the wires and brackets. Statistical analysis was performed using one-way ANOVA and Tukey's tests.
RESULTS
Significant differences were detected between coated and uncoated wires and brackets for friction with either ZnO or CTS nanoparticles. The mean values of the wires and brackets coated with ZnO and CTS nanoparticles were 0.64±0.24N and 0.85±0.23N, respectively, while they were 1.79±0.61N for the uncoated group. In addition, there was a significant decrease of about 64% and 53% found after coating with ZnO and CTS nanoparticles, respectively. The results of CTS nanoparticle coating were consistent with those of ZnO nanoparticles.
CONCLUSIONS
Friction force decreased significantly after coating of CTS or ZnO nanoparticles. These nanoparticles provide an opportunity to reduce friction during tooth movement, resulting in better anchorage control, reduced treatment time and risk of root resorption.
Topics: Chitosan; Dental Alloys; Friction; Humans; Materials Testing; Nanoparticles; Orthodontic Appliance Design; Orthodontic Brackets; Orthodontic Wires; Stainless Steel; Surface Properties; Titanium; Zinc Oxide
PubMed: 33610486
DOI: 10.1016/j.ortho.2021.01.009 -
American Journal of Orthodontics and... Aug 2014The manufacturing process for copper-nickel-titanium archwires is technique sensitive. The primary aim of this investigation was to examine the interlot consistency of...
INTRODUCTION
The manufacturing process for copper-nickel-titanium archwires is technique sensitive. The primary aim of this investigation was to examine the interlot consistency of the mechanical properties of copper-nickel-titanium wires from 2 manufacturers.
METHODS
Wires of 2 sizes (0.016 and 0.016 × 0.022 in) and 3 advertised austenite finish temperatures (27°C, 35°C, and 40°C) from 2 manufacturers were tested for transition temperature ranges and force delivery using differential scanning calorimetry and the 3-point bend test, respectively. Variations of these properties were analyzed for statistical significance by calculating the F statistic for equality of variances for transition temperature and force delivery in each group of wires. All statistical analyses were performed at the 0.05 level of significance.
RESULTS
Statistically significant interlot variations in austenite finish were found for the 0.016 in/27°C (P = 0.041) and 0.016 × 0.022 in/35°C (P = 0.048) wire categories, and in austenite start for the 0.016 × 0.022 in/35°C wire category (P = 0.01). In addition, significant variations in force delivery were found between the 2 manufacturers for the 0.016 in/27°C (P = 0.002), 0.016 in/35.0°C (P = 0.049), and 0.016 × 0.022 in/35°C (P = 0.031) wires.
CONCLUSIONS
Orthodontic wires of the same material, dimension, and manufacturer but from different production lots do not always have similar mechanical properties. Clinicians should be aware that copper-nickel-titanium wires might not always deliver the expected force, even when they come from the same manufacturer, because of interlot variations in the performance of the material.
Topics: Calorimetry, Differential Scanning; Copper; Dental Alloys; Dental Stress Analysis; Humans; Materials Testing; Nickel; Orthodontic Wires; Pliability; Quality Control; Stress, Mechanical; Surface Properties; Temperature; Titanium; Transition Temperature
PubMed: 25085305
DOI: 10.1016/j.ajodo.2014.05.017 -
International Orthodontics Dec 2022The aim of this in vitro study was to compare friction forces generated by the following archwires: rhodium-plated aesthetic Gummetal® (E-GM), Gummetal® (GM),...
OBJECTIVE
The aim of this in vitro study was to compare friction forces generated by the following archwires: rhodium-plated aesthetic Gummetal® (E-GM), Gummetal® (GM), stainless steel (SS) and titanium-molybdenum alloy (TMA), according to bracket-wire angulation and archwire cleanliness.
METHODS
One hundred and ninety-two samples of four orthodontic alloys (E-GM, GM, SS, and TMA) were prepared. The samples were divided into two groups: uncleaned and cleaned using 99% isopropanol in an ultrasonic bath, then subdivided into three subgroups according to bracket-wire angulation: 0°, 5° and 10°. Using a universal testing machine, the wires were pulled through SS maxillary right canine brackets to test static friction forces according to bracket-wire angulation and wire cleanliness. Representative specimens were evaluated to assess surface morphology and roughness.
RESULTS
There were significant differences in static friction forces between archwires when analysed by bracket-wire angulation and cleanliness (P<0.001) except for the 0° uncleaned group. Overall, TMA archwires produced the highest friction while SS wires showed the lowest friction at 0° and 5°. E-GM wires showed comparable friction to SS at 0 (cleaned and uncleaned), but significantly higher friction than SS at 5 (uncleaned) and 10° (cleaned). GM wires had comparable friction to SS at 0° (cleaned and uncleaned), but significantly less friction at the 5° (cleaned) and 10° (cleaned and uncleaned). Compared to GM, E-GM had significantly higher friction at 5 and 10° (cleaned and uncleaned). Cleaning wires reduced surface roughness but increased overall friction.
CONCLUSION
E-GM wires generate higher frictional resistance forces compared to GM and SS, especially at higher bracket-wire angulations and when cleaned. GM friction forces are comparable to SS and thus could be used for space closure with sliding mechanics. However, E-GM wires are not ideal for the same purpose.
Topics: Orthodontic Wires; Friction; Dental Alloys; Orthodontic Brackets; Titanium; Dental Stress Analysis; Materials Testing; Esthetics, Dental; Niobium; Stainless Steel; Orthodontic Appliance Design
PubMed: 35995715
DOI: 10.1016/j.ortho.2022.100683 -
Clinical and Experimental Dental... Jun 2021To investigate the efficacy of polyether-ether-ketone (PEEK) wire as a fixed orthodontic retainer, by comparing its performance to other retainer wires and optimizing...
OBJECTIVES
To investigate the efficacy of polyether-ether-ketone (PEEK) wire as a fixed orthodontic retainer, by comparing its performance to other retainer wires and optimizing its adhesion to composite bonding materials.
MATERIALS AND METHODS
Retainer wires of 15 mm segments were used, PEEK wires were prepared in cylindrical form with 0.8 mm diameter, and had two surface treatments namely air-abrasion and conditioning with adhesive system. Three different metallic retainer wires were used for comparison and three tests were performed; two tests measured debonding force and associated wire deflection from acrylic blocks and bovine teeth and one test for pull-out force. To test debonding force, a vertically directed compressive force was applied to the retainer wires bonded to the acrylic blocks and bovine teeth, while for pull-out test; a vertically directed tensile force detached the retainer wire.
RESULTS
In both debonding tests, PEEK wires (regardless the surface treatment) had non-significant difference when compared to each other, or to the other metallic wires, except the dead-soft coaxial wire group. The dead-soft coaxial wire group had significant difference when compared to other groups regarding both the force magnitude and maximum deflection, the only exception was the debonding force of the flat braided retainer wires bonded to bovine teeth. In pull-out test PEEK wires conditioned with adhesive system and the air-abraded recorded the second and third highest readings respectively.
CONCLUSIONS
Within the limitations of this study, the 0.8 mm round PEEK wires have comparable performance-in terms of debonding and pull out forces-to conventional retainers when bonded with 4 mm composite bonding spots; using air-abrasion for 10 s at 3.5 MPa provided sufficient adhesion of the composite to the wire, and conditioning with adhesive system may provide no further clinical benefit.
Topics: Animals; Benzophenones; Cattle; Dental Bonding; Ethers; Humans; Ketones; Orthodontic Appliance Design; Orthodontic Wires; Polymers
PubMed: 33314768
DOI: 10.1002/cre2.377 -
The Angle Orthodontist Mar 2015To test the hypothesis that treatment time, debris/biofilm, and oral pH have an influence on the physical-chemical properties of orthodontic brackets and arch wires.
OBJECTIVE
To test the hypothesis that treatment time, debris/biofilm, and oral pH have an influence on the physical-chemical properties of orthodontic brackets and arch wires.
MATERIALS AND METHODS
One hundred twenty metal brackets were evaluated. They were divided into four groups (n = 30) according to treatment time: group C (control) and groups T12, T24, and T36 (brackets recovered after 12, 24, and 36 months of treatment, respectively). Rectangular stainless-steel arch wires that remained in the oral cavity for 12 to 24 months were also analyzed. Dimensional stability, surface morphology, composition of brackets, resistance to sliding of the bracket-wire set, surface roughness of wires, and oral pH were analyzed. One-way analysis of variance, followed by a Tukey multiple comparisons test, was used for statistical analysis (P < .05).
RESULTS
Carbon and oxygen were shown to be elements that increased expressively and in direct proportion to time, and there was a progressive increase in the coefficient of friction and roughness of wires as a function of time of clinical use after 36 months. Oral pH showed a significant difference between group T36 and its control (P = .014).
CONCLUSIONS
The hypothesis was partially accepted: treatment time and biofilm and debris accumulation in bracket slots were shown to have more influence on the degradation process and frictional force of these devices than did oral pH.
Topics: Adolescent; Adult; Biofilms; Carbon; Chemical Phenomena; Dental Alloys; Dental Deposits; Electron Probe Microanalysis; Friction; Humans; Hydrogen-Ion Concentration; Materials Testing; Microscopy, Electron, Scanning; Orthodontic Brackets; Orthodontic Wires; Oxygen; Saliva; Stainless Steel; Surface Properties; Time Factors; Young Adult
PubMed: 25023707
DOI: 10.2319/032914-234.1