The effects of third-order torque and self - Saint Louis University

with elastomeric ligatures). Friction values obtained from
both passive self-ligating sets at ±5 degrees remained
significantly smaller than the friction produced by the
Victory set, likely due to the absence of any other than
incidental contact from ligation within these self-ligating
bracket-slots.
With the exception of the In-Ovation R set and
positive angles, increasing the torque from ± 5 to ±10
degrees brought the frictional resistances from the self-
ligating attachment-sets to magnitudes similar to those
from the Victory sets. This finding contrasted outcomes
from a previous study 44 that found self-ligating brackets to
produce smaller frictional forces than traditionally
ligated brackets with torque placed. In the present
research, interaction of the wire with the slot walls, as
well as with the ligating mechanism, would be expected to
occur when approaching ±10 degrees of torque, possibly
tempering the alleged advantage of smaller frictional
resistance that is commonly associated with self-ligating
brackets. The marked increase in friction found in the
self-ligating (but not in the Victory) sets when increasing
the torque from ±5 degrees to ±10 degrees suggest that
there were faciolingual force additions from substantial
contacts with the ligating mechanisms. The In-Ovation R
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