title: Failure evaluation after a 6-year retention period: a comparison between glass fiber-reinforced (GFR) and multistranded bonded retainers.
abstract: OBJECTIVE
  The aim of this study was to compare bond failure and breakage rates of two types of bonded lingual orthodontic retainers (GFR and .0175" multistranded stainless steel wire [MST]) after a 6-year retention period.
  
  
  METHODS
  Eighty-five young adults were randomly divided into two groups: 40 subjects received 48 GFR retainers (14 maxillary and 34 mandibular retainers), and 45 subjects received 50 MST retainers (18 maxillary and 32 mandibular retainers). A Fisher's exact test was performed in order to identify significant differences in the percentage of detachment and breakage of the retainers between the groups.
  
  
  RESULTS
  The maxillary detachment rates were 21.42% for the GFR group and 22.22% for the MST group; the mandibular detachment rates were 11.76% for the GFR group and 15.62% for the MST group. The maxillary breakage rates were 7.14% for the GFR group and 16.66% for the MST group; the mandibular breakage rates were 8.82% for the GFR group and 15.62% for the MST group. The differences were not statistically significant.
  
  
  CONCLUSIONS
  GFR and multistranded stainless steel retainers showed similar results in terms of bond failure and breakage after 6 years of retention. The use of GFR retainers as a retention strategy should not be discouraged and could be considered a viable esthetic alternative to stainless steel wire retainers.
authors.affiliation: Via XX Settembre 20, 16121 Genova, Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Bolla
authors.forename: Mauro
authors.initials: M
authors.lastname: Cozzani
authors.forename: Tiziana
authors.initials: T
authors.lastname: Doldo
authors.forename: Mattia
authors.initials: M
authors.lastname: Fontana
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate; D016009:Chi-Square Distribution; D003722:Dental Alloys; D001840:Dental Bonding; D004868:Equipment Failure; D005260:Female; D005898:Glass; D006801:Humans; D008297:Male; D018704:Orthodontic Retainers; D009969:Orthodontic Wires; D013193:Stainless Steel; D055815:Young Adult
chemical_list: D003722:Dental Alloys; C009753:fiberglass; D013193:Stainless Steel; D017438:Bisphenol A-Glycidyl Methacrylate