A composite resin is a tooth-coloured plastic mixture filled with glass (silicon dioxide) first introduced in the 1960s. Initially, they were only used for front teeth as they were not strong enough for back teeth. However, modern improvements to their composition make them generically suitable today.
The main advantage of composite fillings is their aesthetic appeal. The main disadvantage is their life expectancy as it depends on the depth of cavity and its position in the mouth as to how long they will last; your dentist is best positioned to advise you.