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.