title: An investigation into bisphenol-A leaching from orthodontic materials.
abstract: OBJECTIVE
  To quantitatively determine the bisphenol-A (BPA) leached from orthodontic materials during simulated intraoral exposure.
  
  
  METHODS
  Samples of orthodontic materials were subjected to simulated abrasion, immersion in artificial saliva, thermal shock via temperature cycling, and simulated intraoral exposure. Sample aliquots were collected for up to 2 weeks after artificial saliva immersion, derivatized, then analyzed for BPA by gas chromatography/mass spectroscopy.
  
  
  RESULTS
  Quantifiable amounts of leached BPA were observed from a thermoformed orthodontic retainer material (7.63 µg/g of material) and an orthodontic adhesive (2.75 µg/g of material). BPA leaching was only observed within the first 3 days of artificial saliva immersion.
  
  
  CONCLUSIONS
  Under the test conditions, BPA was observed to leach from two orthodontic materials. While the quantities of leached BPA were below the reference dose for daily intake, existing data of low-dose effects and medical disorders associated with elevated urinary BPA levels suggest that BPA exposure, and thus the use of the leaching materials identified in this study, should be reduced or eliminated.
authors.affiliation: a  Private Practice, East Saint Paul, Manitoba, Canada.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Kotyk
authors.forename: William A
authors.initials: WA
authors.lastname: Wiltshire
mesh_terms: D001559:Benzhydryl Compounds / Q000737:chemistry*; D020770:Compomers / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D020724:Elastomers / Q000737:chemistry; D052244:Endocrine Disruptors / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007101:Immersion; D008422:Materials Testing; D009967:Orthodontic Appliances; D016910:Orthodontic Brackets; D018704:Orthodontic Retainers; D009971:Orthodontics, Corrective; D010636:Phenols / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D012464:Saliva, Artificial / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D020770:Compomers; D003764:Dental Materials; D020724:Elastomers; D052244:Endocrine Disruptors; D010636:Phenols; D019279:Resin Cements; D012464:Saliva, Artificial; C477790:Transbond XT; C006780:bisphenol A; D000098826:Bisphenol A Compounds