What is a Root Canal Treatment (RCT)?

RCT is a procedure that involves cleaning out, disinfecting, and sealing off the inside (pulp chamber / nerve) of a tooth. It is a time consuming, ‘fiddly’, but not painful job.

Why do I need it?

It is normally done because the nerve of the tooth is dead and/or infected. This normally happens because decay gets into the inside of the tooth. It can also happen when a tooth dies because it has a very large or deep filling, or if a tooth suffers trauma. Infected teeth cause very painful dental abscesses if not treated. Sometimes RCT is required to build up a tooth with a crown. When there is not enough tooth to build up with routine treatment we can place a ‘post’ into the tooth and use it as an anchor to hold a porcelain crown to build up the tooth to its proper size and shape etc. We cannot place a post inside a tooth unless RCT has been done. The alternative to RCT is usually the extraction of the tooth.

What does it involve?

RCT is normally a two visit procedure. The first stage involves cleaning out any decay and/or old filling, opening up the inside of the tooth and cleaning everything out. Local anaesthetic is normally given for both visits even though the tooth is normally dead and in theory does not need it. I always play safe and use plenty of anaesthetic. Once the tooth is cleaned out, a disinfectant dressing is placed inside and sealed in with a temporary filling. This disinfectant is left inside for two to four weeks to thoroughly disinfect the inside of the tooth. You need to be careful with the temporary filling during this time; often, small chips will come off it or it may sink into the tooth slightly, this is not a problem. The tooth may be slightly sore for one or two days due to inflammation around its root.

The second stage starts with local anaesthetic followed by the removal of the temporary filling and the disinfectant. If there is no infection left the inside is filed and shaped correctly so that I can then seal off the inside of the tooth to prevent infection getting in again. Again the tooth may be slightly sore for one or two days due to inflammation around its root. Sometimes if you are unlucky the infection has not gone and the tooth needs another dose of disinfectant. If the second stage is not completed within two months of the first stage the disinfectant loses its potency and the tooth becomes infected again and the whole RCT needs to be started again.

Once the RCT is completed the tooth is filled with a long term temporary white filling. The tooth needs to be checked three months later with a view to a permanent restoration, either a post retained crown or a posterior composite (a high strenght white filling).

Possible complications

RCT’s are not 100% successful there is a failure rate of 5 to 10%. This means that there is a chance that the tooth can become infected and/or painful in the future. If this happens it normally happens in the first three months after the RCT. If you unlucky enough to be in this position you have two choices:

1) A new RCT normally done by a specialist or
2)Extraction of the tooth.

In the long term a tooth with a RCT (or any dead tooth) becomes brittle. They normally have very large fillings already and increased brittleness means chunks of the tooth can fracture off leaving very little tooth left behind. Often a tooth with a RCT needs a crown to build it up and prevent this sort of fracture. If a tooth fractures under the gum level it often means that the tooth needs extraction despite having a RCT already.

Small metal files are used to clean out and shape the inside of the tooth. Sometimes small pieces of the files break off and get left inside the tooth. This is not normally a problem as they usually seal off the inside off well. It can complicate things if the tooth needs a new RCT in the future.