title: Microleakage between composite/wire and composite/enamel interfaces of flexible spiral wire retainers: direct versus indirect application methods.
abstract: OBJECTIVE
  The aim of this in vitro study was to compare the microleakage of flexible spiral wire retainers (FSWR) at composite/wire and composite/enamel interfaces produced by an indirect application method to that of a conventional direct application method.
  
  
  METHODS
  Forty freshly extracted human mandibular incisor teeth were randomly divided into two equal groups. Group 1 was bonded directly according to the manufacturer's recommendations. Group 2 consisted of 20 teeth bonded indirectly with Transbond LR as the adhesive and Sondhi Rapid Set A/B Primer (3M Unitek, Monrovia, CA, USA), a filled resin primer. After bonding, specimens were further sealed with nail varnish, stained with 0.5% basic fuchsine for 24 h, sectioned and examined under a stereomicroscope that measured microleakage at the composite/wire and composite/enamel interfaces from both mesial and distal margins. Statistical analyses were performed using Wilcoxon and Mann-Whitney U-tests with Bonferroni correction.
  
  
  RESULTS
  Statistical comparisons indicated that no statistically significant differences were observed between composite/wire and composite/enamel interfaces for direct vs. indirect application procedures (Direct method p = 0.630 and Indirect method p = 0.930). Comparisons of the microleakage scores between direct and indirect FSWR application groups at composite/wire and composite/enamel interfaces indicated no statistically significant microleakage differences at mesial or distal margins (Composite/enamel interface p = 0.361 and Composite/wire interface p = 0.270).
  
  
  CONCLUSIONS
  The type of FSWR application procedures (direct vs. indirect) did not significantly affect the amount of microleakage at the enamel/composite/wire complex.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey. dtahmetyagci@hotmail.com
authors.forename: A
authors.initials: A
authors.lastname: Yagci
authors.forename: T
authors.initials: T
authors.lastname: Uysal
authors.forename: H
authors.initials: H
authors.lastname: Ertas
authors.forename: M
authors.initials: M
authors.lastname: Amasyali
mesh_terms: D003188:Composite Resins; D001840:Dental Bonding / Q000379:methods*; D003763:Dental Leakage / Q000209:etiology*; D006801:Humans; D007180:Incisor; D015588:Observer Variation; D018704:Orthodontic Retainers / Q000009:adverse effects*; D009969:Orthodontic Wires / Q000009:adverse effects; D019279:Resin Cements; D018709:Statistics, Nonparametric
chemical_list: D003188:Composite Resins; D019279:Resin Cements; C481385:Transbond LR