Unfortunately fillings don’t last forever, in fact it is even possible for them to fall out. The average duration of a filling is about 3 – 7 years though you will need to go for regular dental exams to make sure that it is still holding up. If you notice any discolouration, chipping or darkening beneath the filling, then it is time to make an appointment with your dentist. These are all signs that the filling needs to be replaced due to more extensive tooth decay beneath the filling itself.