title: Effect of Enamel Preparation and Light Curing Methods on Microleakage under Orthodontic Brackets.
abstract: OBJECTIVE
  This study aimed to compare the microleakage beneath metallic brackets following two different methods of enamel preparation and light curing.
  
  
  METHODS
  A total of 120 bovine deciduous lower incisors were randomly divided into four groups of 30 teeth. The preparations were as follows: Group I: Acid etching + Transbond XT primer + direct illumination, group II: acid etching + Transbond XT primer + transillumination, group III: Transbond XT self-etching primer + direct illumination and Group IV: Transbond XT self-etching primer + transillumination. Dye penetration was used as the method of microleakage evaluation. Sections made at the enamel-adhesive and adhesive-bracket interfaces were evaluated under a stereomicroscope. The Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis. The level of significance was set at P<0.05.
  
  
  RESULTS
  All groups showed greater microleakage at the gingival in comparison to the incisal margin and the differences were significant among groups with transillumination (P<0.001). No significant differences were observed in the microleakage scores at the gingival and incisal margins in any of the interfaces (P>0.05). Mesiodistal margins of the self-etching group with direct illumination showed significantly lower scores in comparison with acid etched group (P<0.05).
  
  
  CONCLUSIONS
  Use of self-etching primers for bonding of orthodontic brackets yields acceptable results if all bracket margins are cured directly.
authors.affiliation: Professor, Orthodontics Research Center, Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Pakshir
authors.affiliation: Assistant Professor, Orthodontics Research Center, Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Shabnam
authors.initials: S
authors.lastname: Ajami
keywords: Orthodontic brackets; Self-etch primer; Transillumination