[Different applications of various wire alloys in fixed appliance technic]

Steel, beta-Titanium and NiTi archwires (0.016 inch) as well as twisted steel wires (0.0175 inch) were subjected to a bending test. The results were presented graphically. Steel (Tru-Chrome), beta-Titanium (TMA), the twisted steel wires and only one NiTi wire (Nitinol) showed linear force-deflection-diagrams. The other NiTi alloys showed a curved line with a constant force in the middle part. The superelastic wires delivered the same initial force, whether 2 or 4 mm activated. The larger the deformation the longer became the range with a constant force (superelasticity). With an activation of 1 mm a conventional force deflection diagram was found. The steel wire (Tru-Chrome) showed the steepest curve, followed by TMA, Nitinol, some superelastic wires, Twistflex and Respond as well as Pentacat. The last two wires showed an identical diagram. The NiTi-alloy Sentalloy yellow was comparable to Wild Cat, Sentalloy blue to Respond. Some examples of the application of the different arch wires in patients are presented.