Prospective randomized clinical trial to compare pain levels associated with 2 orthodontic fixed bracket systems

Introduction: In this randomized clinical trial, we compared pain levels associated with 2 fixed appliance systems during initial orthodontic tooth movement. Methods: Sixty-six patients (36 female, 30 male) were randomly allocated to either a conventional twin bracket (Tru Straight, Ormco Europe, Amersfoort, The Netherlands) or a self-ligating bracket (Damon 3, Ormco). Both arches were bonded, and a 0.014-in superelastic copper-nickel-titanium archwire was ligated in position. Pain intensity levels were recorded twice a day, over 7 days, by using 10-cm visual analog scales. Patients also recorded whether analgesia was taken. Contact point displacements were measured on study models to calculate Little's irregularity index. Results: Fifty-two patients (78.8%) completed the trial (84.8% in the Tru Straight group and 72.7% in the Damon 3 group). Patients in the Damon 3 group reported lower mean maximum pain intensity (P = 0.053) and significantly lower mean pain intensity (P = 0.012) than did the Tru Straight patients. Patients who consumed analgesics reported significantly higher mean maximum pain intensity and mean pain intensity than those who did not take analgesia (P <0.001). The Damon 3 patients generally reported lower pain intensity than the Tru Straight patients. Conclusions: Although there were wide interindividual variations, in this study, the Damon 3 appliance resulted in lower pain intensity, on average, when compared with the Tru Straight appliance. (Am J Orthod Dentofacial Orthop 2009;136:160-7)