Amalgam (silver) fillings have been used for over 150 years, and do contain mercury. As Amalgam fillings do not bond to the teeth, they do not add extra strength. Over the years, eventually leakage and cracks can occur around the filling. With advances in technology there are now newer mercury free, teeth coloured fillings which are just as strong and durable.
Resin fillings provide a natural aesthetic appearance and technological advances mean they are very realistic and strong for posterior fillings. Tooth coloured filling materials can also be used for aesthetic reasons to close gaps, change the shape of the tooth, thus enhancing smiles in a non-invasive manner.