Comparative analysis of real and ideal wire-slot play in square and rectangular archwires.

OBJECTIVE To evaluate the degree to which the height, width, and cross-section of rectangular and square orthodontic archwires affect the play between the archwires and the bracket slot. MATERIALS AND METHODS The stated measurements (height and width) of 43 archwires from six different manufacturers were compared with real values obtained using a digital gauge. The curvature (radius) of the edge bevels was also measured to calculate the play within the slot, and this measurement was compared with the ideal value. RESULTS The real height and width of the archwires differed from those stated by the manufacturers, falling within the range -6.47% and +5.10%. The curvature of each bevel on each archwire cross-section was shown to differ, and consequently increased the real play between the archwire and slot with respect to the ideal to different degrees. CONCLUSIONS The archwire-slot play was greater than the ideal for each archwire considered, inevitably leading to a loss of information within the system.