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

We investigated the surface modification of orthodontic stainless steel wire using electrophoretic deposition (EPD) of bioactive glass (BG). BG coatings were characterized by spectrophotometry, three-dimensional (3D) focal laser scanning microscopy and scanning electron microscopy. The mechanical properties of the BG-coated wires were estimated nanoindentation, three-point bending and drawing friction tests. BG-coated specimens prepared at higher voltage showed higher values for both reflectance and L^* compared to those prepared at lower voltage. Specimens coated at higher voltage had significantly lower surface roughness than those coated at lower voltage, and their BG layers had higher hardness and elastic modulus values. In the three-point bending test, BG-coated wires produced significantly lower elastic modulus than non-coated wires. Most BG-coated specimens produced similar frictional forces to those produced by non-coated specimens. The surface modification technique applying EPD and BG coating to orthodontic stainless steel wire could be used to develop new esthetical orthodontic wire.