Tip efficiency of a customized lingual appliance: Performance of wires with two different ligatures.

Tip control in lingual orthodontics may be challenging because of the presence of a vertical slot and the particular configuration of the customized appliances. The aim of this in vitro experimental study was to investigate the role of the ligature-wire-slot system in achieving better tip control. A set of customized lingual brackets was obtained for a dedicated typodont made of extracted human teeth. A compression/traction machine tested two types of ligatures in combination with seven different wires, and the tipping angle of each configuration was derived. A statistically significant difference was found between ligatures when the complete set of data was tested. In addition, differences between ligatures were found when testing each wire separately. A statistically significant difference was found among all wires. Full-size wires showed the smallest angles, which correspond to the greatest efficiency of the slot-archwire-ligation system in terms of tip control, and this efficiency appeared to be ligature-related. The role played by the type of ligature was more relevant for undersized wires.