If my filling is still in place and my tooth does not hurt, why does my dentist want to replace the filling?
Constant pressure from chewing, grinding and clenching can cause dental fillings to wear away, chip and even crack. If the seal between the tooth enamel and the filling breaks down, food particles and decay-causing bacteria can work their way under the filling. You then run the risk of developing additional decay in that tooth. Decay that is left untreated will eventually progress to deeply infect the tooth, a condition that can lead to abscesses and even tooth loss.
In cases of large restorations or extensive decay, there is sometimes not enough remaining tooth structure to support a replacement filling. In these cases, we may need to replace the filling with a natural-looking dental crown.