Comparison of physical properties of commonly used stainless steel orthodontic wires with recently introduced newer wires

Author: 
Ramakant M. Doddamani

Introduction: Stainless steel wires have been the workhorse of the orthodontic profession for generations and have found great acceptance in modern day orthodontic treatment. The purpose of the present study is to evaluate and compare the physical properties, mainly the ultimate tensile strength and microhardness of the wires as well as to study the surface topography and crystalline structure.
Materials and Method: Seven types of wires were used in this study. To eliminate operator bias, each wire had been designated a particular alphabets In addition, scanning electron microscopic studies of the Crystalline structure at the fracture site and surface topography. Tests for comparing the tensile properties, micro hardness, surface topography and crystalline structure were performed.
Results
Tensile Properties
It is found that ultimate tensile strength and yield strength was highest for Wilcock wires and lowest for Dentaurum's super spring hard. The difference between means is very highly significant.
Microhardness
It is found that microhardness valuesWORD was highest for Wilcock's extra special test followed by special plus and lowest for T.P. Original wire premier plus.
Surface Topography
The qualitative assessment revealed that T.P. Original wire has a smooth surface finish and is also treated with a chemical cleanser.)
Fracture Characterization
Wilcock wires demonstrated a ductile type of fracture. Unisil demonstrated a cup and cone type of fracture.
Conclusion: The present study has revealed that laboratory tests alone do not seem capable of identifying major short comings of a new wire material. From this study, it appears that a combination of simple mechanical tests & electron microscopic studies, ought to be most relevant. However, to determine the exact properties of the wire, it must be subjected to in-vivo clinical conditions and then tested for various properties.

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DOI: 
http://dx.doi.org/10.24327/ijcar.2023.2193.1479
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Volume12