A study on kinetic frictional properties in Begg/KB orthodontic appliances at posterior sites

In Begg and KB techniques, the kinetic frictional force generated between their characteristic orthodontic appliances at posterior sites and the orthodontic wire affects the efficiency of tooth movement. We compared the kinetic frictional force between the recent orthodontic appliances for posterior sites: the by-pass loop-KB buccal tube system (loop-KB tube system) and the conventional by-pass clamp-round buccal tube system (clamp-round tube system), and elucidated the frictional properties of the loop-KB tube system. We used 016"/018" round wires (016/018 round) and 022" × 016" ribbon wire (022 ribbon) with anchorage bend/curve applied. The results obtained were as follows:

1)	The kinetic frictional energy was significantly larger in the loop-KB tube system than in the clamp-round tube system for all the degrees of anchorage bend with 016/018 round, and not significant between in both systems with 022 ribbon.
2)	With 016/018 round, the kinetic frictional energy became larger with the increase of the degree of anchorage bend in two systems.