[The cause of brackets lost in fixed appliance].
OBJECTIVE
To discusses the causes of brackets lost in fixed appliance.


METHODS
Thirty-eight patients received three kinds of adhesives, with a total of adhesive brackets 1,303, including 325 edgewise brackets and 978 Begg brackets. The three adhesives were JJ enamel adhesive, TF non mixed orthodontic adhesive and 3M light-cured composite.


RESULTS
The overall rate of bracket lost was 54.3% (707/1,303), including 63.8% in mandibular teeth brackets, 36.2% of maxillary teeth brackets. On statistical analysis, there were significant differences between 3M light cured composite and other two adhesives (chi(2)=24.39, 8.63, P<0.01), but no significant difference between the JJ enamel adhesive and TF no-mixed orthodontic adhesive (chi(2)=1.48, P>0.05).


CONCLUSIONS
There were many factors related to bracket lost. The lowest rate of bracket lost was noted in 3M light cured composite among three adhesives.
Department of Dentistry, Yueyang Hospital of Shanghai Chinese Medical University, Shanghai 200437, China.
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