In the center of the tooth there is a space called the root canal. This canal contains the dental pulp, which includes the nerves and blood supply for the tooth.
Root canal treatment is needed when irreversible damage occurs to this pulpal tissue. The damage to the nerve is often made apparent by either pain and/or darkening round the top of the root of the tooth on X-ray.
Damage to the dental pulp may occur for many reasons, including: -
- Deep fillings
Procedure for Root canal Treatment
There are a number of tests, including x-rays, which can be undertaken to check the vitality of a dental pulp.
A hole is then drilled through the top (premolars and molars), or back (incisors and canines) of the tooth to gain access to the root canal.
The most important factor determining the success of a root canal is that it is free of bacteria when it is filled. For this reason we isolate the tooth with a rubber dam to prevent bacterial contamination from the rest of the mouth. The canals are then located and cleaned and shaped to a fine taper. We have a specialized hand piece which locates exactly where the root filling should extend to and automatically reverses when this point is reached.
Once the canals are shaped, they are sealed close to the tip using the latest technology, a synthetic material called Gutta Percha, it is placed into the bottom part of canal then heat moulded to shape before soft Gutta Percha is then moulded to the top portion of the canal.
To complete a root canal treatment may take several appointments, and between visits, a dressing is placed within the canals. This dressing is bactericidal (that is, kills bacteria), and will sterilize a canal a seven days period- thus a minimum of a week is required between appointments. In addition irrigations, and on some occasions an ozone machine, are also used to help to sterilise the canals.
The root canal itself only involves the filling into the canals in the roots of the tooth. Once the root canal is completed we need to restore the coronal part of the tooth-that is the part which appears above the gum line. A filling is placed to restore the tooth into the bite.
In the long term most root filled teeth ideally require a crown for strength, aesthetics and function. This is because teeth that require root canal treatment often have little remaining of their original tooth tissue, this combined with the additional material removed to complete the root canal means that they are substantially weakened. A crown caps over the tooth and holds it together providing protection from fracture. The tooth can generally be prepared for the crown at the same time as the filling, is placed to save time in the long term. The filling is still required with the provision of a crown as the crown simply caps over the top of the tooth – the filling fills in the space in the centre of the tooth.
The cost of the crown or restoration is additional to the cost of the root canal. We are happy to provide you with a written estimate.
Root canal treatment has a very high success rate if the canals are able to be properly cleaned and sealed, and the tooth restored appropriately. Success rates vary from 92-96% for a tooth with visible infection round the tip of the root to 82% for a tooth with a visible area of infection on x-ray. The success rate for re-treatment of a root canal which has previously failed is 62%. Results from research into why root canal treatment fail has enabled us to employ new techniques and irrigations which we expect will increase these success rates.
Root canals are very fine and often curved, so instruments may occasionally fracture within a canal. Sometimes these can be removed; however, they may also be sealed in as part of the root canal filling without compromising the success of the treatment.
Pain or discomfort may occur between appointments. This is common immediately after an appointment, as the medicaments placed within the canal take time to work. Sometimes an infection may need to be treated with antibiotics.
Difficulty in locating canals can sometimes lead to a perforation (that is, an instrument going outside the tooth) if this occurs it can generally be repaired – although referral to a specialist (endodontist) may be necessary.
If a root canal is required through an existing crown, this may compromise the existing crown either necessitating its replacement or shortening its life span.
Occasionally if can be difficult to negotiate and clean canals completely.
Infection or pain rarely continues after root canal treatment. If this occurs further treatment will be required.