Assessment of frictional resistance and surface roughness in orthodontic wires coated with two different nanoparticles

2022 ◽  
Author(s):  
Ramiro Estacia Silveira ◽  
Carlos Nelson Elias ◽  
Flávia Lucisano Botelho Amaral
Keyword(s):  
Surface Roughness ◽  
Frictional Resistance ◽  
Orthodontic Wires

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

2020 ◽  
Author(s):  
Laila Baidas ◽  
Huda Alkawari ◽  
Nada Alshihah ◽  
Ghaida Almashaan ◽  
Haya Alwaalan
Keyword(s):  
Surface Roughness ◽  
Reflux Disease ◽  
In Vitro Study ◽  
Frictional Resistance ◽  
Vitro Study ◽  
Distilled Water ◽  
Orthodontic Wires ◽  
Beta Titanium ◽  
Orthodontic Archwires

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.

scholarly journals Surface roughness of three types of modern plastic bracket slot floors and frictional resistance

2013 ◽  
Vol 84 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Sung-Hwan Choi ◽  
Da-Young Kang ◽  
Chung–Ju Hwang
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Three Dimensional ◽  
Frictional Resistance ◽  
Lower Surface ◽  
Reinforced Plastic ◽  
Ceramic Brackets ◽  
Sliding Test ◽  
Plastic Brackets

ABSTRACT Objective: To quantitatively analyze the surface roughness of the slot floors of three types of modern plastic brackets and to measure static frictional force during sliding mechanics in vitro. Materials and Methods: Control groups comprised stainless steel brackets and monocrystalline ceramic brackets. Test groups comprised three types of 0.022-in slot, Roth prescription, plastic, maxillary right central incisor brackets. Test groups included glass fiber-reinforced polycarbonate, filler-reinforced polycarbonate, and hybrid polymer with inserted metal slot brackets. The static frictional resistance caused by sliding movements with an archwire (stainless steel) in vitro was quantitatively analyzed. Both scanning electron microscope and three-dimensional optical surface profiling were used. Results: Scanning electron microscope and three-dimensional optical surface profiler revealed that all as-received brackets had irregular slot floor surfaces, and both irregularity and roughness increased after the archwire sliding test. The ceramic brackets in the control group showed significantly lower surface roughness values and higher frictional values during the archwire sliding test compared with the other brackets. The glass or filler-reinforced plastic brackets exhibited significantly higher static frictional values than the metallic slot type brackets (P &lt; .001). The hybrid polymer with inserted metal slot brackets showed relatively lower surface roughness and frictional values compared with the stainless steel control bracket. Conclusion: Glass or filler-reinforced plastic brackets showed higher frictional resistance than metallic slot–type brackets. A plastic bracket with inserted metal slot may be the best choice among plastic brackets for low frictional resistance and to avoid damage from sliding movements of the archwire.

scholarly journals Analysis of Aspect Ratio in a Miniature Rectangle Channel for Low Frictional Resistance

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1580
Author(s):  
Takashi Fukuda ◽  
Makoto Ryo Harada
Keyword(s):  
Surface Roughness ◽  
Reynolds Number ◽  
Aspect Ratio ◽  
Rectangular Channel ◽  
Frictional Resistance ◽  
Experimental System ◽  
Cross Sectional ◽  
Friction Resistance ◽  
Calculation Results ◽  
Volume Range

We conducted a theoretical investigation of the cross-sectional aspect ratio of a rectangular channel to have sufficiently low frictional resistance under less than 150 of the Reynolds number. From the theoretical consideration, it was clarified that 3.40 or more is recommended as a criterion for determining the aspect ratio. This addresses the problem of determining the interval of rectangle channels, installed in a plate reactor. There is a concern that the real system does not follow the analytical solution, assuming laminar flow, since the higher aspect ratio leads to disturbances of the flow such as the emergence of vortices. However, in the channel’s volume range of (W × H × L) = (7.0 mm × 0.38 mm × 0.26 m), such a turbulence was not observed in the detailed numerical calculation by CFD, where both calculation results were in agreement to within 3% accuracy. Moreover, even in an experimental system with a surface roughness of ca. 7%, friction resistance took agreement within an accuracy of ±30%.

scholarly journals Frictional resistance of orthodontic wires tied with 3 types of elastomeric ligatures

2011 ◽  
Vol 25 (6) ◽  
pp. 526-530 ◽  
Author(s):  
Amanda Carneiro da Cunha ◽  
Mariana Marquezan ◽  
Amanda Osório Ayres de Freitas ◽  
Lincoln Issamu Nojima
Keyword(s):  
Frictional Resistance ◽  
Orthodontic Wires

THE EFFECTS OF SURFACE ROUGHNESS ON FRICTION REDUCTION AS THE RESULT OF SURFACE TEXTURING BY ABRASIVE JET MACHINING

Tribologia ◽  
2016 ◽  
Vol 267 (3) ◽  
pp. 195-204
Author(s):  
Sławomir WOŚ ◽  
Waldemar KOSZELA ◽  
Paweł PAWLUS
Keyword(s):  
Surface Roughness ◽  
Friction Force ◽  
Surface Texturing ◽  
Frictional Resistance ◽  
Friction Reduction ◽  
Textured Surfaces ◽  
Sliding Surfaces ◽  
Abrasive Jet Machining ◽  
Oil Pockets

Various machining methods are currently used to obtain the best co-action of sliding surfaces. Application of two-process surfaces led to a decrease of frictional resistance. Textured surfaces after abrasive jest machining are practical examples of two-process topographies. The results of the application of textured discs with the same array of oil pockets of similar sizes, but with different roughness in areas free of dimples, are presented in this paper. It was determined that after this type of machining, the effect of the friction force decrease was caused by surface texturing.

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