NiTi or Stainless Steel wires are coated with Teflon/5META/Tooth colored epoxy resins. four Coating supplies are artificial resin or plastic resins which include epoxy resins.three Coating increases esthetics and lessens friction but there are a few drawbacks too. Stainless Steel: Orthodontists started working with this type of steel for wires https://www.ortix.co.uk/wires/