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

to incisor irregularity after initial alignment was
found. 78,79
Other Factors Influencing Friction
Saliva
Although the role of saliva as a potential lubricant
for the sliding of wires through slots has been studied by
several researchers, there has been no clear answer as to
the effect of saliva on intraoral friction. In one of the
earliest studies, Andreasen and Quevedo 44 found no
significant difference in friction between “wet” and “dry”
samples. Possible explanations for this finding were the
following: 1. Saliva may not be good lubricant for the slot
and wire materials; or 2. Forces at the contact area shared
by the wire and bracket-slot were so great that the fluid
was expelled from that area. Tselepis, Brockhurst and
West 33 found a significant reduction in friction in the
“wet” state. Saunders and Kusy 87 similarly found a decrease
in friction when saliva was introduced between two
contacting titanium surfaces. Others have found, however,
some increases in frictional resistance with the addition
of saliva. 17,53,83 These conflicting results were suggested
by Kusy, Whitley and Prewitt 27 to be related to the surfaces
in contact. They found that the lubricating or adhesive
27