Comparative evaluation of frictional resistance of silver-coated stainless steel wires with uncoated stainless steel wires: An In vitro study

Abstract

Background:Silver is known for its antimicrobial activity. Silver coating effectively reduces Lactobacillus acidophilus and Streptococcus mutans count, thus reducing chances of dental plaque and caries. This silver coating may have effect on frictional property of orthodontic wires.Aim:The aim of this study is to evaluate and compare frictional resistance of silver-coated and uncoated stainless steel (SS) wires.Methods:Forty SS wires were divided into four groups of 10 each: Group 1 – 0.017 × 0.025 inch SS wires (silver coated), Group 2 – 0.017 × 0.025 inch SS wires (control), Group 3 – 0.019 × 0.025 inch SS wires (silver coated), and Group 4 – 0.019 × 0.025 inch SS wires (control). Surface modification of wires was carried out by the thermal vacuum evaporation method with silver (10 nm size) using vacuum-coating unit model. The frictional resistances of all forty wires were checked on forty 0.022 × 0.028 inch slot central incisor brackets (SS wires and brackets from American Orthodontics, St Paul, USA) mounted on metal plates using universal testing machine.Results:There was no significant difference found in frictional resistance between silver-coated and uncoated 0.017 × 0.025 inch SS wires group (P = 0.854). Statistically significant reduction in frictional resistance was observed in 0.019 × 0.025 inch coated SS wires in comparison to uncoated wires (P = 0.032).Conclusion:Overall silver coating either did not affect the frictional resistance (0.017 × 0.025 inch SS wires) or reduced it (0.019 × 0.025 inch coated SS wires) compared to uncoated wires. Findings suggest that the use of silver-coated SS wires in routine orthodontic practice can be implemented after further in vivo human clinical trials.

Functional Surface Coatings on Orthodontic Appliances: Reviews of Friction Reduction, Antibacterial Properties, and Corrosion Resistance

“…Nanosilver coatings can reduce the surface roughness of SS brackets [ 63 ] or NiTi archwires [ 66 ], but the change in friction between brackets and archwires is not obvious [ 63 ]. Moreover, silver (Ag) plating on 0.019 × 0.025-inch coated SS archwires significantly reduces the friction between the brackets and the archwires, while 0.017 × 0.025-inch SS archwires do not significantly reduce the friction [ 67 ]. The 0.019 × 0.025-inch SS archwires, whether coated or not, have higher friction than the 0.017 × 0.025-inch SS archwires.…”

“…The play between 0.019 × 0.025-inch SS archwires and the slots is smaller, so the pressure is higher when the slots are of the same size. After applying the coating, the friction coefficient of the surface should be the same regardless of the size of the archwires, so the alteration of the friction force of the archwires subjected to more pressure may be relatively more obvious when the other conditions are the same [ 67 ]. However, this explanation has not yet been clearly confirmed.…”

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

“…While few studies measured the mechanical properties of SS wires coated with other materials, such as TiN and silver [ 17 , 18 ], the effect of Zn coating on the improvement of mechanical properties, such as tensile strength, flexural strength, and friction resistance of NiTi wires has been supported [ 11 ].…”

Evaluation of friction on self-ligating and conventional brackets associated with different types of archwires submitted to sliding mechanics

“…The frictional resistance present when performing orthodontic sliding mechanics results from interactions between the bracket, arch and method of ligation [1][2][3][4][5][6][7][8][9] .…”

“…A high frictional coefficient may reduce the force used for orthodontic movement by half, diminishing the speed of tooth movement and making it difficult to control anchorage. The frictional force should be as low as possible with the goal of achieving greater mechanical efficiency; that is, the force applied must be sufficient to break the static friction and enable tooth movement 2,6,9,[10][11][12][13] .…”