RESUMEN
Aim: The objective of this study was to measure and compare the in vitro performance of active and passive self-ligating brackets in orthodontic rotation by means of an electromagneticfield simulation. Methods: The study sample consisted of 32 mandibular right central incisor brackets (n=8), slot 0.022", that were divided into the following groups: 1) BioQuick® (Forestadent, Pforzheim, Germany) active brackets; 2) In- Ovation®R (Dentsply-GAC, Central Islip, New York, USA) active brackets; 3) Damon-Q® (Ormco, Orange, California, USA) passive brackets, and 4) Smartclip® (3M, Monrovia, California, USA) passive brackets. The orthodontic wire used was CuNiTi round section 0.016", thermoactivated at 35o C (ORMCO- Orthodontics Glendora, California, USA). The experiment wasperformed in a simulator machine, composed of two fixedlateral axes and a movable central axis, which simulated the dental rotation. Qualitative analysis (n = 4) was performed using SEM. After the descriptive and exploratory analysis, the yield and grade data were submitted to one-way analysis of variance (ANOVA) followed by the Tukey test, considering the level ofsignificance of 5%. Results: In-Ovation®R brackets showedsignificantly higher yield than BioQuick® and Damon-Q®. Damon-Q® brackets presented a significantly lower mean valuethan In-Ovation R and Smartclip®. BioQuick® did not differsignificantly from Damon-Q® and Smartclip®. In-Ovation®R did not differ significantly from Smartclip®. Conclusion: In the present study, it was observed that there is a difference in rotational control in the different self-ligating brackets tested being the best rotational control was the In-Ovation R® group (active), followed in descending order by the groups Smartclip® (passive), Bioquick® (active) and Damon Q® (passive)