title: A randomized controlled trial to investigate brackets bonded with a hydrophilic primer.
abstract: OBJECTIVE
  To compare the clinical failure rates of brackets bonded using a prototype hydrophilic primer, designed to be insensitive to moisture, with brackets bonded with a conventional primer.
  
  
  METHODS
  Single centre randomised controlled clinical study. Thirty-three patients were bonded using a split mouth technique: randomly allocating the hydrophilic primer to one side of the mouth and a conventional primer to the other.
  
  
  METHODS
  Hospital orthodontic department, Bradford, UK.
  
  
  METHODS
  Orthodontic patients requiring fixed appliances.
  
  
  METHODS
  The site and time to bond failure was recorded for each bracket that failed over 6 months.
  
  
  RESULTS
  Using survival analysis, there was an increased risk of bracket failure when bonded with the hydrophilic primer compared with the conventional primer (hazard ratio = 2.2, 95% confidence interval: 1.1 to 4.5, P = 0.01).
  
  
  CONCLUSIONS
  This hydrophilic primer cannot be recommended for routine clinical use.
authors.affiliation: Department of Orthodontics, St Luke's Hospital, Little Horton Lane, Bradford, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Littlewood
authors.forename: L
authors.initials: L
authors.lastname: Mitchell
authors.forename: D C
authors.initials: DC
authors.lastname: Greenwood
mesh_terms: D000293:Adolescent; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002648:Child; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements / Q000737:chemistry*; D004868:Equipment Failure; D006801:Humans; D016910:Orthodontic Brackets; D016016:Proportional Hazards Models; D016037:Single-Blind Method; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D014867:Water / Q000737:chemistry
chemical_list: D003738:Dental Cements; D014867:Water; C065742:Transbond; D017438:Bisphenol A-Glycidyl Methacrylate