Aim: The aim of this in vitro study was to evaluate the frictional resistance of esthetic active and passive self-ligating brackets (SLB) and conventional brackets (CB) made up of different materials ligated with different methods at crowded configuration. Materials and methods: One active SLB, two passive SLBs, one metal, one monocrystalline alumina, one polycrystalline alumina, and one copolymer bracket were used. The 0.014” Ni-Ti archwires were ligated in bracket slots on the metal plates and canine brackets were placed 2 mm superiorly and 2 mm buccally. All CBs were ligated with metal ligatures, conventional elastomeric ligatures (CEL), and nonconventional elastomeric ligatures (NCEL), respectively. The pulling speed of the wire was set to 10 mm/min for 30 sec for each sample. Results: Passive SLBs showed significantly lower friction than active SLB and CBs when ligated with metal ligatures and CEL, except copolymer brackets. Brackets ligated with NCEL showed lower friction than active SLB. Conclusion: CBs ligated with NCEL showed similar friction values to passive SLBs and lower compared to active SLB at the initial phase of the treatment.
(Rev Esp Ortod. 2013;43(4):216-221)