However , compared to multistranded stainless steel wires , pain in subjects with superelastic nickel-titanium archwires was significantly greater at 12 h ( t = 2.34 ; P = 0.0193 ) , as well as at day 1 in the morning ( t = 2.21 , P = 0.0273 ) , afternoon ( t = 2.11 , P = 0.0346 ) and at bedtime ( t = 2.03 , P = 0.042 ) .