Detection of Bisphenol A in dental wastewater after grinding of dental resin composites.

OBJECTIVES: This study evaluated the release of bisphenol A (BPA) in wastewater after grinding of resin composites and tested three filtration materials. METHODS: Three resin composites (Ceram X, Filtek Supreme XTE and Core-X flow) were used. Samples (5mm×2mm, n=10) were prepared using a metal mold and were polymerized for 20s according to manufacturers' instructions. A dental unit was disconnected from wastewater circulation and composite samples were ground under standardized procedures (200,000rpm; 90s). Wastewater was collected in glass bottles. Water samples were collected as control by performing the same procedure without grinding resin composite. All samples were stored at 7°C for 6 months to simulate storage. Then they were analyzed by HPLC-FLD. Three filtration materials (Zeosorb, Katalox Light and Catalytic Carbon) were used for water treatment to remove BPA. BPA-water solutions were prepared; corresponding to the highest amount released by the resin composites. These solutions were analyzed before and after filtration by HPLC-FLD and their efficacy (%) was calculated. RESULTS: BPA was detected in all composite solutions: Ceram X and Filtek Supreme XTE showed similar findings (p>0.05) which were significantly higher than the control (p<0.001) and Core-X flow (p=0.001). The efficacy of the filtration materials was: Katalox Light (5.09%)