There are two types of filling available.
1) Tooth coloured filling
2) Silver filling
Tooth coloured filling is made up of a nontoxic composite resin that can be exactly matched to your existing natural tooth colour. This material bonds to the tooth creating a tight, superior fit to the natural tooth. Composite resins are a better alternative because it is tooth coloured which helps to create a long lasting beautiful smile. Fortunately, silver fillings can safely be replaced with tooth coloured restorations.
Traditionally, people use to have Silver/ Amalgam fillings in their mouth. But there are many disadvantages of using it as it contains 50 percent of mercury, a highly toxic and harmful metal which causes minor to lethal following complications and hence avoided by the dentist now a days but still in some cases it is indicated.
-The metal of a silver filling expands/ contracts, resulting in fracture of filling.
-Discolouration of tooth.
-Spongy gums and bleeding teeth.
-Tooth becomes loose in the socket.
-Digestive disturbances, psychological problems and asthma.
-UK Department of Health issued a warning to pregnant women to avoid having dental amalgam fillings during pregnancy to avoid possible harm to foetus.