How can fresh cavities form at the margins of sliver amalgam fillings on teeth?

Question

Silver amalgam fillings predominantly contain silver a known bactericidal agent and mercury which a known toxin and has bactericidal property. So how is it that the plaque bacteria survive near the filling margins and produce fresh caries?

Answer 1

Simply put, bacteria overcame the bactericidal properties of the filling. How remains to be determined. The mechanism for this is being heavily researched in labs all around the world. So you are not alone in asking this question.