Effects of sp2/sp3 Ratio and Hydrogen Content on In Vitro Bending and Frictional Performance of DLC-Coated Orthodontic Stainless Steels

Abstract

Abstract:This study investigated a diamond-like carbon (DLC) coating formed on stainless steels (disk and wire specimens) using a plasma-based ion implantation/deposition method with two different parameters (DLC-1, DLC-2). These specimens were characterized using high-resolution elastic recoil analysis, microscale X-ray photoelectron spectroscopy and nanoindentation testing to determine the hydrogen content, sp 2 /sp 3 ratio and mechanical properties of the coating. Three-point bending and frictional properties were estimated. DLC-1 had a diamond-rich structure at the external surface and a graphite-rich structure at the inner surface, while DLC-2 had a graphite-rich structure at the external surface and a diamond-rich structure at the inner surface. Mean mechanical property values obtained for the external surface were lower than those for the inner surface in both types of DLC-coated specimens. The hydrogen content of DLC-2 was slightly higher versus DLC-1. Both DLC-coated wires produced a significantly higher elastic modulus according to the three-point bending test versus the non-coated wire. DLC-2 produced significantly lower frictional force than the non-coated specimen in the drawing-friction test. The coating of DLC-1 was partially ruptured by the three-point bending and drawing-friction tests. In conclusion, the bending and frictional performance of DLC-coated wire were influenced by the hydrogen content and sp 2 /sp 3 ratio of the coating.

Perspectives of the Friction Mechanism of Hydrogenated Diamond-Like Carbon Film in Air by Varying Sliding Velocity

“…Therefore, lots of low-friction materials, coatings, and lubricants have been prepared and discovered to regulate the process of friction and wear in machine elements [2,3]. Among the various materials, diamond-like carbon (DLC) film is considered to be one of the most promising solid lubrication materials for industry applications owing to its outstanding physical, chemical, tribological, and optical properties [4][5][6][7].…”

The Influence of Carbon Coatings on the Functional Properties of X39Cr13 and 316LVM Steels Intended for Biomedical Applications

“…From the data of Table 2, it can be concluded that the thickness of the DLC layer was similar on each substrate. In contrast, the hydrogen content of the DLC layer was very dependent on the surface treatment applied to the metals, as also observed by Muguruma [35] and Bewilogua [30]. In this sense, RF PACVD showed more than double hydrogen content in DLC layer than that produced by RMS.…”

Effects of bioactive glass coating by electrophoretic deposition on esthetical, bending, and frictional performance of orthodontic stainless steel wire

“…The frictional force between the bracket and archwire during tooth movement is a primary issue in orthodontics. If the frictional force can be decreased, then the efficiency of tooth movement can be improved 31,32) . These frictional properties are attributed to multiple factors such as surface roughness, hardness, elastic modulus, and the cross-sectional dimensions of the orthodontic wires and brackets 31,32) .…”

“…If the frictional force can be decreased, then the efficiency of tooth movement can be improved 31,32) . These frictional properties are attributed to multiple factors such as surface roughness, hardness, elastic modulus, and the cross-sectional dimensions of the orthodontic wires and brackets 31,32) . A recent study reported that commercially available esthetic coating wire influences the frictional properties of the wire 11) ; esthetic polymer coating may increase frictional resistance due to increased wirebinding at the edge of the bracket.…”

“…The frictional forces generated by each wire/bracket combination were measured under dry conditions at room temperature (25°C) using a custom-fabricated drawing-friction testing device attached to a universal testing machine (EZ Test, Shimadzu) 31) . Each bracket was bonded to a stainless steel plate with a non-filled adhesive resin (Superbond, Sun Medical), and a bracketmounting device provided 0° or 10° angular positioning for the bracket.…”