Self-ligating vs conventional twin brackets during en-masse space closure with sliding mechanics.
BACKGROUND
The aim of this study was to compare the rate of en-masse space closure with sliding mechanics between passive self-ligating SmartClip brackets (3M Unitek, Monrovia, Calif) and conventional twin brackets ligated with stainless steel ligatures.


METHODS
Nineteen patients including 20 arches participated in this prospective trial with 0.018-in slot brackets. All patients had first premolar extractions in at least 1 arch, with the second premolar and the first molar distal to the extraction site bonded with SmartClip brackets on 1 side and conventional twin brackets on the other. The sides were alternated with each consecutive patient. Space closure was achieved on 0.016 x 0.022-in stainless steel wires with nickel-titanium coil springs activated 6 to 9 mm. The patients were recalled every 5 weeks until 1 side had closed. The distances from the mesial aspect of the canine bracket to the distal aspect of the first molar bracket were recorded before and after space closure, and an average rate of space closure per month was calculated.


RESULTS
Thirteen patients completed the trial (14 arches); the median rates of tooth movement for the SmartClip bracket side (1.1 mm per month) and the conventional twin bracket side (1.2 mm per month) were not significantly different (P = .86).


CONCLUSIONS
There was no significant difference in the rate of en-masse space closure between passive SmartClip brackets and conventional twin brackets tied with stainless steel ligatures.
Miles
Peter G
PG
University of Queensland Dental School, Brisbane, Australia. pmiles@beautifulsmiles.com.au
D000293:Adolescent; D000328:Adult; D001641:Bicuspid; D001696:Biomechanical Phenomena; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D016910:Orthodontic Brackets; D019516:Orthodontic Space Closure / Q000295:instrumentation* / Q000379:methods; D009969:Orthodontic Wires; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D013997:Time Factors; D014081:Tooth Extraction