Frictional force released during sliding mechanics in nonconventional elastomerics and self-ligation: An in vitro comparative study

AIM AND OBJECTIVES: The aim of this study is to evaluate the frictional forces generated by five different orthodontic brackets when used in combination with stainless steel (SS), titanium molybdenum alloy (TMA), and nickel-titanium (NiTi) archwires in dry conditions at physiological temperature. MATERIALS AND METHODS: Five different types of maxillary upper right side self-ligating brackets (SLBs) (Damon 3MX, Smart Clip and Carriere LX) and conventional SS brackets (Mini 2000, Optimum Series and Victory Series) with a slot size 0.022 inch were coupled with 0.016” NiTi and 0.019 × 0.025” SS/titanium molybdenum alloy (TMA) archwires. Tests were carried out for each group of the bracket-wire combination at physiological temperature and in the dry state. Frictional forces were measured by Instron universal testing machine. RESULTS: SLB showed lower fictional values in comparison with elastic ligatures. Frictional force increased proportionally to the wire size; TMA and NiTi archwires presented higher frictional resistance than SS archwires. CONCLUSION: SS brackets tied with conventional ligatures produced high and low friction when ligated with SLBs with passive clip.