In vitro evaluation of different methods of ligation on friction in sliding mechanics

The aim of this study was to evaluate the effect of different methods of ligation in tie configurations on friction in dry and wet conditions.

Four methods of ligations were used: regular round tie, figure eight, twist, and diagonal. Materials used were Alastik (3M Unitek), Power O module (ORMCO), O-ring ligatures (JES), stainless steel ligatures (TP Orthodontics), 0.019 × 0.025-inch straight-length stainless steel archwires and stainless steel MBT 0.022-inch slot brackets (3M Unitek).

Figure eight ligation had the highest friction, followed by round, twist, and diagonal ligation, in the descending order. Comparisons were statistically significant with a 100-g load. Dry group samples had higher friction than the wet group. These comparisons were statistically significant with a 50-g load.

The study concluded that figure eight ligation had the highest friction, and diagonal ligation produced the least friction. Among the dry and wet groups, lubrication showed significant reduction in friction.