What really made a difference for me was the "laser" whitening. It is bit pricey about $500, at least at my overpriced dent
, for treatment but your teeth whiten several shades in just one sitting. Totally painless too. The Apollo Teeth Whitening System, Xenon Plasma Arc thats the name of this laser. After that he also gave me the regular bleaching tray and that worked a bit too but nothing like the laser.