RESUMO
BACKGROUND: In this study, the authors quantitatively determined the bisphenol A (BPA) leached from intraoral materials during simulated intraoral exposure. METHODS: The authors subjected samples of intraoral materials to simulated abrasion, immersion in artificial saliva, thermal shock via temperature cycling, and simulated intraoral exposure. The authors collected sample aliquots for up to 2 weeks after artificial saliva immersion, derivatized, and then analyzed the aliquots for BPA by gas chromatography and mass spectroscopy. RESULTS: Quantifiable amounts of leached BPA were observed from only 1 of 13 intraoral materials tested: a silicone baby bottle nipple (20 micrograms). BPA leaching was only observed after 3 days of artificial saliva immersion, with no additional leaching thereafter. CONCLUSIONS: Under the test conditions, BPA was observed to leach from a silicone baby bottle nipple. PRACTICAL IMPLICATIONS: Although the quantities of leached BPA were below the reference dose for daily intake, investigators have shown a possible association between low levels of BPA and many medical disorders. BPA exposure, and thus the use of the leaching material identified in this study, should be reduced or eliminated.
Assuntos
Compostos Benzidrílicos/farmacocinética , Materiais Dentários/química , Fenóis/farmacocinética , Humanos , Saliva Artificial , TemperaturaRESUMO
OBJECTIVE: To quantitatively determine the bisphenol-A (BPA) leached from orthodontic materials during simulated intraoral exposure. MATERIALS AND 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.
Assuntos
Compostos Benzidrílicos/química , Materiais Dentários/química , Disruptores Endócrinos/química , Ortodontia Corretiva , Fenóis/química , Compômeros/química , Elastômeros/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Imersão , Teste de Materiais , Aparelhos Ortodônticos , Braquetes Ortodônticos , Contenções Ortodônticas , Cimentos de Resina/química , Saliva Artificial/química , Propriedades de Superfície , Temperatura , Fatores de TempoRESUMO
We report the formation pathway of ScVO(4) zircon from ScVO(3) bixbyite with emphasis on the synthesis and stability of the novel intermediate defect zircon phase ScVO(4-x) (0.0 < x
