Failure to detect any effect of amalgam restorations on peripheral blood lymphocyte populations.

Dental amalgam has been considered to have adverse side effects on the immune system. Reports have been contradictory, indicating both an increase and a decrease in peripheral blood lymphocyte counts associated with amalgam restorations. We investigated two groups of patients, one of which was treated with amalgam restorations for the first time. In the other group, all existing amalgam fillings were removed. Prior to and after treatment, we determined the absolute and relative numbers of granulocytes, lymphocytes, monocytes, T cells, B cells, cytotoxic T cells, helper T cells and natural killer cells. In addition, functional investigations of T cells were performed. We failed to find any effect of amalgam restorations on the immune system in terms of the parameters investigated.