The study said the amount of mercury was reduced to 1.5 micrograms per day after 2 years, in a sterile in vitro environment. The mercury was still there of course, it didn't disappear.
Like we said before, if the mercury, which is substantial, dissolves in your mouth, you'd be missing 50% of your filling.
Other studies have shown mercury exposure between 2-12 micrograms per day from fillings that were older than 2 years old. The question is, is low level exposure to mercury safe? We don't really know the answer to that question yet, but judging from people's experiences with having their fillings removed, I'd say no.