Biopsied? Are they examining it to see if it's mercury? Yes I had an amalgam tattoo around the bottom of my last rear molar. I asked my dentist what it was years ago and she said that it was just a local reaction to my crown. This tooth had a root canal in it. When I went to see my biological dentist, he said that it could be an allergy to crown material or it could be mercury in the gums. The root canal may have even been sealed with mercury! That is why I decided to remove that root canal tooth (which I am sort of regretting). He cut out as much of the tattoo as he could. There was the tiniest bit of discoloration left, but it seems to have pretty much gone away since the surgery. And I am getting better. I read that you could sprinkle chlorella on it along with chelation to draw the mercury out. I didn't try it though as it seems to be resolving on it's own. Maybe it is being pulled out of the gums with DMPS which I am using.