Root canal therapy (potential complications)

Potential Complications of Root Canal treatment

Complications of Root Canal Treatment (Endodontics)

A message from the Australian Dental Association

The pulp is made up of nerve and associated blood vessels that lie within the root canal. Disease in this tissue is a slow cumulative process.

 Root canal treatment (RCT) is a complex procedure requiring a high level of clinical skill that will prevent the loss of a tooth due to the infection of the pulp.

This treatment has a general success rate of 80-85%.

7% of cases will fail to respond to any treatment and will require extraction.

This can be attributed to resistant bacteria, cracks, infection outside the root canal, cyst formation or a foreign body reaction.

The pulp in a tooth becomes diseased for a variety of reasons:

Decay. Once decay is large enough, the bacteria within the decay can enter the pulp.

Large fillings. Although the decay may be arrested just short of the pulp of the tooth by the placement of a filling, some of the bacteria may still cross the thin barrier and cause infection and pain.

Cracks within the tooth can also lead to bacteria entering the pulp

Periodontal or gum disease can lead to bacteria entering the pulp via the gum space

Some medical conditions can lead to unexpected pulp death

Possible complications- although rare, below are listed the complications that could possibly occur during RCT. If any of these situations happen then the patient will be completely informed and a note made on the treatment record. A referral to a specialist endodontist may be required

Fracture of endodontic instruments within the canal. The canals are very fine and can be very curved. Although all care will be taken there is always the risk of a breakage of the fine files. This may or may not lead to failure of the treatment depending on where the fracture is and at what stage of the treatment this occurs.

Perforation of the root during the opening of the canals or placement of a post after the root filling is placed. This would cause the failure of the treatment, as this hole cannot be repaired

Failure to find, and hence treat one or more canals. If a canal cannot be found it may be because of the shape of the particular tooth, or it may be blocked (calcified) by natural means. All efforts will be made to locate all canals but there comes a point where the risk of perforation of the root becomes too high to allow further search. If the tooth does not settle down then this risk will be re-evaluated.

Split tooth   This is where there is a fracture through the tooth from the biting surface to the roots. This will require extraction of the tooth. Splitting can occur before RCT, due to heavy pressures on the tooth and may indeed have caused the symptoms of pain. It is also a risk during and after RCT due to the lack of pain in the tooth combined with the decreased amount of tooth structure compared with the amount of filling. This will allow extra pressure to be placed on the tooth than before, as there is no pain feedback to restrict this. This risk can be minimised with a restoration that covers the entire biting surface of the tooth and/or a crown to spread the load evenly over the tooth.

Under filling of the canal leading to reinfection and retreatment.

Passing of materials through the end of the canal into the surrounding bone

Reinfection of the canals after treatment is finished due to breakdown of the restoration on the biting surface of the tooth.


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