title: Upper bonded retainers.
abstract: OBJECTIVE
  To assess the frequency and type of upper bonded retainer failure and to identify possible predisposing factors.
  
  
  METHODS
  The records of 466 consecutive patients with upper bonded retainers were analyzed retrospectively with respect to retainer failures and failure type as well as timing of failure, differences among operators, and the number of defects of the multibracket appliances (MB) prior to the retention period.
  
  
  RESULTS
  A total of 58.2% of all patients experienced retainer failures. The average failure odds were 1.26 failures per retainer. The odds were highest for 3-3 retainers (1.37) and lowest for the 1-1 retainer (0.54). The detachment and total loss rates were significantly influenced by operator experience-both rates were lower for experienced practitioners. Total retainer losses occurred more frequently in case of previous MB defects, while retainer fractures were seen more frequently when the retainer included the canines.
  
  
  CONCLUSIONS
  Upper bonded retainer failures are a frequent problem during the retention period (58.2% of patients). Less operator experience correlated with higher failure rates. An increased number of total retainer losses must also be expected with a decreasing number of bonding sites and in cases involving previous MB defects.
authors.affiliation: Department of Orthodontics, University of Giessen, Germany. sabine.ruf@dentist.med.uni-giessen.de
authors.forename: Eva
authors.initials: E
authors.lastname: Schneider
authors.forename: Sabine
authors.initials: S
authors.lastname: Ruf
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D002648:Child; D002983:Clinical Competence; D001840:Dental Bonding; D004868:Equipment Failure; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008437:Maxilla; D016910:Orthodontic Brackets / Q000009:adverse effects; D018704:Orthodontic Retainers / Q000009:adverse effects; D012189:Retrospective Studies; D055815:Young Adult