Pharmacokinetics of bisphenol A released from a rental sealant

Background. Limited information is available regarding potentially estrogen ic bisphenol A, or BPA, released from dental sealants. This study determine d the rate- and time-course of BPA released from a dental sealant (Delton O paque Light-cure Pit and Fissure Sealant, Preventive Care/Dentsply) when ap plied at a dosage of 8 milligrams (one tooth) or 32 mg (8 mg on each of fou r teeth) to 40 healthy adults. Methods. The authors recruited 40 healthy subjects (18 men and 22 women, 20 -55 years of age) who did not have histories of pit and fissure sealant pla cement or composite resin restorations. The authors collected saliva (30 mi lliliters) and blood (7 mt) specimens from all subjects immediately before sealant placement (baseline) and at one hour, three hours, one day, three d ays and five days after sealant placement. They used high-pressure liquid c hromatography to determine BPA (detection sensitivity 5 parts per billion, or ppb) in all specimens. Results. The authors detected BPA in some saliva specimens (5.8-105.6 ppb) collected at one hour and three hours. The BPA, however, was not detectable beyond three hours or in any of the serum specimens. For the one- and thre e-hour saliva samples, the BPA concentration in the high-dose (32 mg) group was significantly greater than in the low-dose (8 mg) group (P < .05, Wilc oxon signed rank test). In the high-dose group, there was a significant dec rease in saliva BPA concentrations from one hour to three hours (P < .01, W ilcoxon signed rank test). Conclusion. This study showed that BPA released orally from a dental sealan t may not be absorbed or may be present in nondetectable amounts in systemi c circulation. The concern about potential estrogenicity of sealant may be unfounded.