Nordstrom B, et al. - Experts compared in this randomized clinical trial, the clinical effectiveness of nickel-titanium (NiTi) and niobium-titanium-tantalum-zirconium (TiNbTaZr) archwires during initial orthodontic alignment. A similar ability to align teeth was displayed by Gummetal wires and conventional NiTi wires. Additional advantages of Gummetal wires over conventional NiTi included formability and their use in cases with nickel allergy.