Improvement of binding friction between stainless steel orthodontic wire and bracket by performing Rh-PTFE composite plating on the wire

ABSTRACT Purpose: During orthodontic treatment, it is important to ensure that the least frictional force is applied to the teeth to ensure optimal tooth movement. We applied electrolytic rhodium-polytetrafluoroethylene (Rh-PTFE) composite plating to stainless steel (SS) orthodontic wires with the aim of suppressing friction and corrosion in the wire and facilitating the longevity of treatment. Materials and methods: SS orthodontic wires were plated with a polytetrafluoroethylene (PTFE) particle suspended solution. The surface colour was changed to black with Rh-PTFE plating, and a homogeneous distribution of PTFE particles was observed in the plated layer using scanning electron microscopy (SEM). Results: The friction of Rh-PTFE plated wire with the SS bracket decreased to ½ to 1/3rd of the original force by increasing the PTFE content in the plated layer, despite the increase in surface roughness with plating. Corrosion suppression was also observed when Rh-PTFE plating was applied to a nickel wire. Conclusion: Ensuring smooth movement between the wire and bracket decreases the risk of metal dissolution, which can be effectively be achieved with Rh-PTFE plating. This finding will significantly assist orthodontists in choosing plated wires to ensure a more effective course of treatment for their patients in the future.