The reasons you would need a root canal are:
- The nerve is dying or has died
This is definitely the most common reason for a root canal to be performed. It is most likely to happen as a result of dental decay
. Less commonly, it is due to trauma or cracked teeth. If the tooth has irreversible pulpitis
, (due to for example a very deep filling or deep decay) then the damage is such, that the tooth is not able to recover and will die off over time. See
- Signs and symptoms of a root canal
for more of a discussion.
If the tooth is very painful to touch and you can't bite down or chew on it, it is likely you have a dental abscess. It is important that we identify the source of the abscess- is it an acute peri-apical abscess coming from an infected tooth or a periodontal abscess
? An abscess of gum origin is quite different and requires other treatment.
If sensitivity is affecting your life and you can't eat and drink without pain something needs to be done. If all other treatments have failed for sensitive teeth then as a last resort a root canal can be performed.
If you want to restore a tooth but there is not enough tooth left to support a filling
or a crown
, then a post
is required. In order to put a post into the root of a tooth it is necessary to first perform a root canal
, then remove some of the root filling material (GP) without disturbing the seal to allow a post to be placed on which the dentists can build up a core to retain a crown.
On occasions, if you are having cosmetic dental work done- particularly crown and bridges
, the shape of the tooth may need to be changed so much that preparing the tooth will expose the nerve in the middle. In these circumstances a root canal must be planned and performed to prevent nerve pain from the procedure. Orthodontics should be considered as an alternative that will make this unnecessary and preserve your natural teeth
If together with your dentist, you decide it is best to keep some roots either for a precision attachment to help hold in a denture or simply to help preserve the supporting bone, then the roots of the teeth on which the denture will sit, need to be root filled and sealed. To simply leave them underneath will cause them to decay away, give pain and eventually require extraction.
Root treatment may be considered for teeth where the nerves are questionable- where perhaps extensive restorations are planned. Especially if a tooth is to serve as part of a bridge, then it can make sense to choose to root fill the tooth before this is done. If root treatment is not carried out and the nerve becomes painful or dies off after the bridge has been fitted, it will be a lot more difficult to treat- the likelihood of success will be lower, and the fit and finish of the bridge affected.
- Sclerosis ('narrowing') of the nerve canal
If you have knocked or banged a tooth then sometimes the tooth responds by laying down more dentine (known as secondary dentine) and progressive X-rays will show the space for the canal inside disappearing. At this point root treatment may be considered while the canal is still easily accessible, though studies have shown that only up to 15% of these 'sclerosed teeth' may actually cause any problems in the future.