Like nicotine from cigarettes, alcohol,chemicals, drugs, onions and everything else that you swallow, the particles that drop off your fillings and the vapour you breathe in off these fillings, (which are 60% mercury to help bind all the other metals together in an amalgam of metals), are uptaken in your bloodstream.
Through digestion and entry to the bloodstream, mercury also comes through your breastmilk and straight into your baby-- IF you have fillings and eat mercury-laden fish like Tuna, salmon, crustacea etc.
What to do? stop the fish at least.
But its too dangerous to have the fillings removed because so much particulate is drilled out and vapourised in the dental surgery. You inhale this.
Of course, safe removal is possible but its best not to whilst breast feeding.
Have fillings out BEFORE conception and do chelation treatments to rid your body of it.