title: Bisphenol A release from orthodontic adhesives measured in vitro and in vivo with gas chromatography.
abstract: BACKGROUND
  The objectives of this study were to quantify in vitro the Bisphenol A (BPA) release from 5 orthodontic composites and to assess in vivo the BPA level in patients' saliva and urine after bracket bonding with an orthodontic adhesive system.
  
  
  METHODS
  For the in-vitro portion of this study, 5 orthodontic composites were evaluated: Eagle Spectrum (American Orthodontics, Sheboygan, Wis), Enlight (Ormco, Orange, Calif), Light Bond (Reliance Orthodontic Products, Itasca, Ill), Mono Lok II (Rocky Mountain Orthodontics, Denver, Colo), and Transbond XT (3M Unitek, Monrovia, Calif). Simulating intraoral conditions, the specimens were immersed in a water/ethanol solution, and the BPA (ng.g-1) liberation was measured after 30 minutes, 24 hours, 1 day, 1 week, and 1 month by the gas chromatography system coupled with mass spectrometry. Twenty patients indicated for fixed orthodontic treatment participated in the in-vivo study. Saliva samples were collected before bracket bonding and then 30 minutes, 24 hours, 1 day, 1 week, and 1 month after bonding the brackets. Urine samples were collected before bonding and then at 1 day, 1 week, and 1 month after bonding. The results were analyzed statistically using analysis of variance and Tukey posttest, with a significance level of 5%.
  
  
  RESULTS
  All composites evaluated in vitro released small amounts of BPA. Enlight composite showed the greatest release, at 1 month. Regarding the in-vivo study, the mean BPA level in saliva increased significantly only at 30 minutes after bonding in comparison with measurements recorded before bonding.
  
  
  CONCLUSIONS
  All orthodontic composites released BPA in vitro. Enlight and Light Bond had, respectively, the highest and lowest BPA releases in vitro. The in-vivo experiment showed that bracket bonding with the Transbond XT orthodontic adhesive system resulted in increased BPA levels in saliva and urine. The levels were significant but still lower than the reference dose for daily ingestion.
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. Electronic address: marilia.moreira@ig.com.br.
authors.forename: Marília Rodrigues
authors.initials: MR
authors.lastname: Moreira
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Leonardo Gontijo
authors.initials: LG
authors.lastname: Matos
authors.affiliation: Department of Chemistry, College of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Israel Donizeti
authors.initials: ID
authors.lastname: de Souza
authors.affiliation: Department of Chemistry, College of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Tamires Amabile Valim
authors.initials: TA
authors.lastname: Brigante
authors.affiliation: Department of Chemistry, College of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Maria Eugênia Costa
authors.initials: ME
authors.lastname: Queiroz
authors.affiliation: Department of Orthodontics, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Fábio Lourenço
authors.initials: FL
authors.lastname: Romano
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Paulo
authors.initials: P
authors.lastname: Nelson-Filho
authors.affiliation: Department of Orthodontics, Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Mírian Aiko Nakane
authors.initials: MA
authors.lastname: Matsumoto
mesh_terms: D001559:Benzhydryl Compounds / Q000032:analysis*; D002849:Chromatography, Gas; D003188:Composite Resins; D003738:Dental Cements / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D016910:Orthodontic Brackets; D010636:Phenols / Q000032:analysis*; D019279:Resin Cements / Q000737:chemistry*; D012463:Saliva / Q000737:chemistry*; D014556:Urine / Q000737:chemistry*; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D003188:Composite Resins; D003738:Dental Cements; D010636:Phenols; D019279:Resin Cements; C000617892:Eagle Spectrum; C418867:Enlight; C000617893:Light Bond; C000617894:Mono Lok II; C477790:Transbond XT; C006780:bisphenol A; D000098826:Bisphenol A Compounds