I am hoping to have my amalgam fillings safely removed. Which is likely to be more important to minimise mercury absorption: the use of a rubber dam or breathing via a separate nasal air supply. I have consulted two mercury free dentists: one offers the dam, the other the nasal air supply. Neither offers both. Is anyone aware of any scientific research which has measured blood mercury levels before, during and after amalgam removal using different removal methods and precautions?