Change in the bisphenol A content in a polycarbonate orthodontic bracket and its leaching characteristics in water.

The change in the bisphenol A (BPA) content in a polycarbonate (PC) orthodontic bracket and its leaching characteristics were studied by immersing the bracket in water because BPA has been the matter of controversy in dentistry due to its estrogenic potential. PC brackets were placed in water at 37 degrees C and 60 degrees C and the BPA content in the bracket and the amount of BPA released into the water were analyzed at appropriate intervals by high performance liquid chromatography. The BPA content increased in the water with time and was 3.8-fold after 12 months at 37 degrees C and 12.4-fold after 14 weeks at 60 degrees C compared with the virgin value. The rate of BPA release also increased with time. The results suggested that BPA was released from the bracket time-dependently in the oral cavity. However, it was assessed that little or no estrogenic effect due to the released BPA is expected in the human body.