title: Long-term evaluation of clinical performance of direct-bonded brackets: an epidemiologic survey.
abstract: OBJECTIVE
  The objective of the current epidemiologic study was to investigate characteristics associated with bracket failure in bonded brackets.
  
  
  METHODS
  A retrospective study on data of 144 patients treated during 2009 to 2012 was done. Baseline data including age, gender, malocclusion, bite type and debonding incidences per teeth were retrieved. ANOVA analysis and t-test were used to evaluate the data.
  
  
  RESULTS
  Second premolar teeth had significantly higher debonding incidences. Patients' age was negatively correlated with debonding incidences. No difference was observed for various types of malocclusion (class I, II and III), arch side (right or left) or arch location (upper or lower). However, deep bite patients had significantly higher failure incidents.
  
  
  CONCLUSIONS
  For a total of 144 patients with 2,524 bonded brackets, the overall failure rate was 7.8%. Deep bite was the only factor that was associated with higher bracket failure. The bracket failure incidents tend to decrease as patients age increase.
  
  
  CONCLUSIONS
  Deep bite patients and also second premolar teeth seem to be especially prone to debonding incidents. Care must be taken to avoid premature contacts in deep bite patients. Also strict adherence to moisture control protocols when bonding second premolar teeth is recommended since these teeth are at increased risk for debonding.
authors.affiliation: Associate Professor, Department of Orthodontics, Tabriz School of Dentistry, Iran.
authors.forename: Mohamad Hossein
authors.initials: MH
authors.lastname: Ahangar Atashi
authors.forename: Mohamadreza
authors.initials: M
authors.lastname: Shahamfar
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001641:Bicuspid / Q000473:pathology; D002648:Child; D001840:Dental Bonding / Q000706:statistics & numerical data*; D016021:Epidemiologic Studies; D004868:Equipment Failure / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008310:Malocclusion / Q000145:classification; D016910:Orthodontic Brackets / Q000706:statistics & numerical data*; D057887:Overbite / Q000145:classification; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult