<<Disclaimer: Verify this information before applying it to your situation.>> Two responses were received regarding whether anyone had tried the Nupro-Gold teeth whitening treatments for whitening teeth. Again, the company Dentsply (1-800-989-8825) did verified that the bleaching solution is g-f. One stated he had used the Nupro-Gold treatment with no problems. He used it daily for 2 weeks then once or twice a month thereafter for two hours at a time. He said using it overnight could cause temporary sensitivity and pain. He also said, according to his dentist, after two hours you get no additional benefit. It improved his teeth a lot but not to the point where he would call them white. The other person who responded used a different brand (Nite White Excel2 from Discus Dental) and said his teeth were significantly whitened. He did the treatment five or six nights but had to remove the trays two times in the middle of the night because the bleach made his tongue uncomfortable. Hope this information is helpful to others. Mary Anne