Evaluating the Mechanical Properties of Zinc-Coated Stainless Steel Orthodontic Wires Using Physical Vapor Deposition.

Maryam Karandish,Milad Moghimi,Dana Jafarpour,Mahmoud Pakshir,Caren Bavaresco

doi:10.1155/2021/6651289

Maryam Karandish, Milad Moghimi + Show 3 more

Open Access

https://doi.org/10.1155/2021/6651289

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Abstract

The aim of this study was to evaluate the mechanical properties of stainless steel (SS) orthodontic wires coated with zinc (Zn), using a Physical Vapored Deposition (PVD) machine. A total of 100 straight SS orthodontic wires were cut into pieces of 5 centimeters in length and were divided into two groups. Half of the wires were coated with Zn using a PVD machine, and the others remained uncoated. Tensile strength (n = 15), three-point bending (n = 15), and frictional resistance at 0° (n = 10) and 10° (n = 10) were measured to compare the mechanical properties of the Zn-coated and uncoated orthodontic wires using the universal testing machine. The surface of the coated wires was observed by SEM and AFM. An independent t-test, multivariate ANOVA, and measurement ANOVA were used for data analysis. SEM and AFM showed a homogenous Zn layer of 0.28 ± 0.006 µm on the SS wires. The tensile strength and three-point bending strength significantly increased after Zn coating of wires with the PVD method (P < 0.05). The friction resistance significantly reduced at both angulations following the coating procedure. The angle between the wire and bracket had no significant effect on the frictional resistance (P > 0.05). Coating with Zn improved the tensile and load-bending strength of SS orthodontic wires and reduced their frictional resistance which might be advantageous in terms of reducing the risk of root resorption during the orthodontic treatment.

Highlights

In recent years, new generations of wire alloys have been introduced in orthodontics
Results e wires were observed by scanning electron microscope (SEM). e Zn particles were homogenously spread all over the wire (Figure 2(a)). e backscatter waves were used to identify the Zn layer, and the mean Zn thickness was measured at 0.28 ± 0.006 μm (Figure 2(b))
To the best of our knowledge, this study is the first to investigate the effect of Zn coating on Stainless steel (SS) orthodontic wires, using the Physical Vapored Deposition (PVD) machine. e null hypothesis was rejected as the findings revealed that Zn coating was able to improve the tensile and load-bending strength and reduce the frictional resistance of SS orthodontic wires

Summary

Introduction

New generations of wire alloys have been introduced in orthodontics. Coated and uncoated specimens were further divided into four groups and subjected to the following tests: (I) tensile strength, (II) three-point bending, and (III) frictional resistance at 0° and 10°. Ere was a significant difference between coated and uncoated wires in terms of three-point bending strength (p < 0.001).

Results

Conclusion