Root Canal Therapy

Root canal therapy is needed when the dental pulp (blood vessels and nerves in the centre of the tooth) becomes infected.

Infection occurs most commonly through a deep cavity that allows bacteria through the enamel and dentin layers and into the pulp. Sometimes the pulp simply dies due to a fracture or a blow to the tooth.

Symptoms of infection

You may realise that you have an infected tooth when:

• The tooth is sensitive to hot or cold.
• The tooth hurts with biting or pressure.
• There is throbbing, severe tooth pain.
• The area is swollen.
• You have a bad taste in your mouth.
• The tooth becomes discoloured (grey or black).

You may also be unaware of the problem because you have no symptoms at all.

Diagnosis

To determine if your tooth has an infected pulp, we do a thorough examination, which often includes X-rays. We may also check for temperature sensitivity (hot/cold), tap lightly on the tooth to see if it is sensitive, look for changes in the tooth’s colour, or press gently on the gums next to the tooth to check for pain.

If we determine that you have an infected tooth, we will talk with you about root canal therapy to remove the infection and save the tooth. It is important to treat an infected tooth in order to prevent the infection from travelling through the root tips and causing a painful abscess in the jawbone.

The Procedure

Root canal therapy is an excellent way to save a tooth that would otherwise die and need to be removed. The procedure usually requires one or two visits and is performed under local anaesthesia.

• A thin sheet of rubber (rubber dam) is placed in the mouth to help maintain a contamination-free environment by preventing saliva and blood from coming into direct contact with the tooth throughout the procedure. It also protects the patient’s airway from any materials which may fall down there during treatment.
• The tooth is opened and very small instruments are used to clean the entire canal space of diseased pulp tissue and to shape the space for filling. The debris is flushed out periodically, and the canals are disinfected.
• Once the tooth is thoroughly cleaned, a temporary filling is placed. The tooth is not permanently filled until it is completely free of active infection.
• At the next appointment, the root canals are sealed with a permanent root canal filling material to prevent bacteria from entering the tooth in the future. The tooth is then restored with a new filling or crown.

Root-treated teeth are weaker and more brittle than live teeth and carry the additional recognised risk of fracturing under pressure. For this reason, it is often advisable to restore the root-filled tooth with a crown to reinforce it. We normally wait a few months after treatment so that we can be sure that the root treatment is okay prior to assessing whether crowning is advisable.