Dental amalgam once used as restorative material for caries will not cause any harm and binds very firmly to the tooth structure mechanically. That is why amalgam is still widely used. The only problem of amalgam contamination is that excess mercury which is mixed with alloy is poured into the water resources which cause mercury poisoning. Safe disposal of mercury must be taken and as such a perfect mix is not of much harm to the body. Know why? Coz am a dentist!