The basic structure of a tooth comprises a crown visible in the mouth and a root, which is covered by your gum. Inside each tooth is the pulp, which consists of all the blood vessels and nerves that keep a tooth alive. This occupies a space in the centre of the tooth called the root canal. Sometimes the pulp or tissue inside the tooth becomes infected or dies and this can lead to toothache (acute). The tissue in the tooth may also become infected at a slower pace and die gradually without causing much discomfort (chronic). Your dentist often diagnoses this from an x-ray or occasionally a small blister may be visible on your gum (sinus).

This is basically a deeper filling where the root of the tooth is filled as well as the crown of the tooth. Our endodontist, Dr Sile Lennon, will open up the root canal or space in the centre of the tooth where the pulp or tissue keeping the tooth alive is. This space is cleaned and washed out using small instruments called files. At a second visit, a rubber based filling material called gutta-percha is placed in the root canal of the tooth.

No, once the tooth has been numbed you should not feel any pain. You may be aware of some pressure occasionally in the tooth. If the tooth is very painful before treatment and you are experiencing a raised temperature and heart rate, it may be advised to take antibiotics for a few days before starting the root filling.

This depends on the tooth that is being filled. For front teeth two visits are normally required, but as back teeth have more roots and root canals (sometimes up to four), more than two visits are sometimes required.

After the root filling is completed a permanent filling is placed in the tooth, but it is very advisable to place a crown on the tooth to prevent fracture of the tooth. The dental crown essentially binds the tooth together and prevents, for example, a side wall breaking off the tooth. The tooth is not weaker but you can now bite a lot harder on the tooth before this is detected by your mouth, and hence place a lot more pressure on the tooth.

Very rarely a tooth may not settle down after a root filling. This may result if there is, for example, still an area of infection around the root tip. In these cases it is necessary to remove this area of infection by surgery. This rarely happens and the tooth can generally be saved.