PATIENTS sometimes blame dental professionals after filling their teeth when pain persists for a period. The general reason why teeth may become sensitive after being filled is because of the drilling and cutting of nerves during the preparation of the cavity for filling. Remember, the tooth is alive and needs some time to heal. However, there are several other explanations for pain around fillings.

Dental sensitivity following the placement of a filling is common. A tooth may be sensitive to pressure, air, sweet foods, or temperature. Usually, the sensitivity resolves on its own within a few weeks. During this time, it is advisable to avoid those things that are causing sensitivity. Pain relievers are generally not required.

For example, you may experience pain when you bite down, which may be observed soon after the anaesthesia wears off and continues over time. In this case, the filling is interfering with your bite. You will need to return to your dentist and have the filling reshaped. Then, there is pain when your teeth touch. This pain is a very sharp sensation that occurs only when your teeth make contact. It is likely caused by the touching of two different metal surfaces (for example, the silver amalgam in a newly filled tooth and a gold crown on another tooth with which it touches). Sometimes, the teeth may even be some distance apart. The two metals form the poles of a “battery” with the saliva being the electrolyte. The pain is really from galvanic shock generated by the resulting electrical current. Sometimes, the pain disappears after a week or so.

If the decay is very deep to the pulp (nerve) of the tooth, there may be a “toothache” pain. This response may indicate that the tissue is no longer healthy or the body has not reacted as it should. In either case, root canal treatment is required.

Then there is what is known as referred pain. With this type of pain, you experience sensitivity or discomfort in other teeth besides the one that received the filling. With this sensation, there is likely nothing wrong with your other teeth. The filled tooth is simply passing along “pain signals” it is receiving to other teeth. This pain should decrease on its own over one to two weeks.

Allergic reactions to silver fillings are rare. In fact, there are fewer than a hundred cases reported in over two centuries, according to the American Dental Association. In these rare circumstances, mercury or one of the metals used in an amalgam restoration is thought to trigger an allergic response. Symptoms of amalgam allergy are similar to those experienced in a typical skin allergy and include rashes and itching. Patients who suffer from amalgam allergies typically have a medical or family history of allergies to metals. Once an allergy is confirmed, another restoration material can be used.

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 check-up. If the seal between your filling and the tooth enamel breaks down, food particles and decay-causing bacteria can work their way under the filling. This is called seepage or recidivism. 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 abscessed tooth. This can lead to terrible pain, loss of the tooth, and even death from conditions such as Vincent’s angina or encephalitis.

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.

New fillings that fall out are probably the result of improper cavity preparation, contamination of the preparation prior to placement of the restoration, or a fracture of the repair from bite or chewing trauma. Older fillings will generally be lost due to decay or fracturing of the remaining tooth structure.

Finally, whatever undesirable symptoms or doubts you may have after having a filling done, it is best to check back with your dentist.