Constant pressure from chewing, grinding, or clenching can cause dental fillings to wear away, chip, or crack. Although you may not be able to tell that your filling is wearing down, your dentist can identify weaknesses in your restorations during a regular checkup.
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 can progress to infect the dental pulp and may cause an abscess.
If the filling is large or the recurrent decay is extensive, there may not be enough tooth structure remaining to support a replacement filling. In these cases, your dentist may need to replace the filling with a crown.