Tooth pain After Filling

With silver-mercury amalgam fillings, some post-operative pain is expected. Since these fillings are metallic, they can conduct hot and cold to the center of the tooth quite easily, and the teeth tend to remain sensitive to temperature for up to eight weeks.

When newer composite fillings hurt, the sensitivity is generally unexpected. These fillings are ordinarily very gentle to the teeth, plus the composite material tends to insulate the tooth rather than conduct heat or cold. So when you do experience pain, we look for other explanations.

Possible causes of tooth pain after a filling:

• Some sensitivity is normal after any tooth has been worked on, especially if there has been tooth decay. Decay irritates the tooth, and working on that tooth irritates it further, to where it can cross the threshold into a painful sensitivity. If this is the only cause, expect the tooth to be getting gradually better, usually within a couple of days, but it can last for several months. As long as the tooth gradually improves, there should be no cause for alarm.
• The technique for doing white composite fillings on back teeth is very demanding, and many general dentists aren't properly trained to do this. The pain after a new filling could be because of improper technique.
• The decay could have been close to the pulp of the tooth. In this situation, some bacteria will always be present in the thin porous dentin between the filling and the tooth. With the tooth being irritated from being worked on, it creates a situation in which the tooth can easily become infected. If the sensitivity persists, it indicates that the tooth is not recovering from this tooth infection and will need a root canal.
• If the tooth is sensitive to biting down, it may need only a simple bite adjustment.
• With composite fillings, there is an unusual kind of sensitivity that sometimes occurs. With this sensitivity, the tooth is not sensitive when you clench your teeth together but will experience a sharp pain when food is chewed. It is not clear what causes this, though it seems to be related to possible bonding failure or contamination of the bond. Some theorize that it is caused by tiny air bubbles that form at the interface between the tooth and the composite that will then hurt when they're compressed. Curiously, it tends to occur most often in smaller fillings. When it occurs, replacing the filling with another composite filling usually eliminates the sensitivity. If left untreated, the sensitivity may go away over a period of several months, or it may get worse.
  The latest technology in placing composite fillings involves the use of what are called "self-etching primers," which appear to practically eliminate this type of sensitivity.
• There are other possible causes for sensitivity or pain after new fillings. A dental examination may be required to discover another source of the problem.