The reputation root canal treatment has acquired is almost entirely borrowed from the pain of the infection, not from the procedure. The infected pulp is what hurts, sometimes badly. The root canal removes the source of that pain. By the time the anaesthetic goes in for the first appointment, the process is going in the right direction.
That said, knowing what is happening and why helps. A procedure that is narrated is a lot easier than one that is not.
When a root canal is actually needed
The nerve and blood supply of a tooth sits in the pulp, which occupies a chamber in the crown of the tooth and extends down into canals in each root. When that pulp becomes irreversibly inflamed or infected, it cannot heal on its own. The causes are usually deep decay that has reached the pulp, a crack that lets bacteria in over time, or a large restoration that has repeatedly stressed the tooth. Occasionally it follows trauma: a knock to the front teeth as a child can leave a tooth that looks and functions normally for years before the pulp quietly dies.
The signs vary. Some teeth declare themselves dramatically with a hot swelling and severe throbbing. Others are diagnosed on an X-ray showing a shadow at the root tip, with nothing more than occasional mild sensitivity. A tooth can have a dead pulp for a long time with no pain at all, and still have an active infection brewing silently.
The alternative to treating it is extracting the tooth. That is a legitimate choice in some situations, and we have written about how that decision gets made. But if the tooth is structurally sound and the patient wants to keep it, a root canal and crown is the pathway.
What happens at the first appointment
We do root canal treatment here in-house. Dr Patricia Tan handles most of our endodontic work; she also teaches dental students at La Trobe University in Bendigo, which keeps her current on technique in a way that general practice alone does not always.
The first appointment is the longer one, usually ninety minutes to two hours.
Local anaesthetic. A properly anaesthetised tooth is comfortable throughout. If you have had root canal treatment where you felt things you should not have, it is usually a case where the anaesthetic was inadequate for the degree of infection, because acidic infected tissue resists local anaesthetic, or where it simply was not given enough time. We add block anaesthetics and supplement where needed. We are not in a hurry on this point.
Rubber dam. Once the tooth is numb, rubber dam goes on. A small sheet of latex is placed over the tooth with a clamp, isolating it from the rest of the mouth. This is not optional. Saliva is full of the same bacteria we are trying to clean out, and contaminating the root canal during preparation is how treatment fails. The rubber dam also prevents small instruments from being swallowed or inhaled, which is a real if uncommon risk without it.
Opening the tooth. We make an access cavity through the crown of the tooth to reach the pulp chamber. If there is still living tissue here, it comes out. If the pulp is already dead, we are cleaning out necrotic material and the bacteria that have colonised it.
Negotiating the canals. Each root has one or more canals, and the number varies. A lower incisor usually has one. An upper molar typically has three, sometimes four. Each canal is scouted with very fine files to find its full length, measured with an electronic apex locator, and confirmed on a radiograph. Getting the working length right is the measurement that everything else in the procedure depends on.
Shaping and cleaning. The canals are widened with a sequence of files, moving apically from the crown end. We use rotary instruments for the mechanical work, and in between files the canals are irrigated with sodium hypochlorite, which dissolves organic debris and kills bacteria in parts of the canal anatomy the files cannot physically reach. Then a final rinse with a chelating solution to remove the smear layer from the dentine walls, which prepares the surface for the obturation material.
Temporary dressing. If the infection is active or the appointment time runs out before we are confident the canals are fully clean, we dress the canals with a calcium hydroxide medicament and seal the tooth with a temporary filling. The temporary seals out the saliva and the bacteria while the medicament works over the following weeks. Some root canals are completed in one appointment; others take two. The decision is clinical, not a billing preference.
Between appointments
The tooth may be sore for a few days after the first appointment, especially if it was acutely infected beforehand. Over-the-counter anti-inflammatories handle most of this. If you develop swelling or the pain escalates rather than settling over 48 hours, contact us.
Avoid chewing on the treated tooth. A tooth with a large access cavity and a temporary filling is not at its structural best, and until the crown goes on it is at higher risk of fracturing under load. If the temporary filling feels high when you bite, ring to have it adjusted; a high bite can make an already sore tooth significantly worse.
The obturation appointment
Once the canals are clean and dry, they are filled. The material is gutta-percha, a rubber-like material that has been the standard for this purpose for well over a century, sealed with a root canal sealer. Gutta-percha is inert and radiopaque, which means we can see it on the final X-ray to verify that the canals are completely filled to the working length, with no voids and no overfill.
The obturation appointment is shorter, usually thirty to forty-five minutes, and generally more comfortable because the infection is cleared.
A post-treatment X-ray is taken and kept in the record. It is the baseline against which any future symptoms or changes at the root tip will be measured.
What happens after
The endodontic treatment itself preserves the nerve space. The tooth still needs a crown.
A tooth that has had root canal treatment is more brittle than a vital tooth. The access cavity has removed a significant portion of the internal crown structure, and the tooth is no longer moisturised from within. Without a crown, it is at high risk of fracturing vertically, and a vertical fracture in a root canal-treated tooth is usually an extraction situation. So while the root canal and the crown feel like two separate jobs, they are really one job in two stages.
We will talk about the crown at the obturation appointment and book it before the temporary restoration fails. The crown preparation and fit follows the same protocol as any crown here: Medit intraoral scanner, e.max or zirconia depending on the location and the bite load, a temporary for the laboratory interval, and air abrasion at the cementation appointment.
For patients who are nervous
Root canal treatment is the most anxiety-provoking procedure most patients anticipate and one of the most straightforwardly comfortable ones they experience. That gap between expectation and reality is real, and it tends to close completely after a first treatment.
For patients who are still very anxious, we have a ceiling TV above every chair, oral premedication for those who want to arrive already settled, and happy gas is available. Tell us what specifically worries you when you book. If it is the noise of the instruments, the length of the appointment, or the idea of what is happening, those are all things we can address differently.
If you have been told you need root canal treatment and you have been sitting on that advice, the infection does not improve over time. Contact us or call (03) 8838 8820. We are at 129A Canterbury Road, Blackburn, with on-site parking and early starts on Wednesdays and Fridays from 8am.
Related reading: seven signs your tooth might need a root canal covers the warning signs before the pain becomes severe. Crown or implant for a badly damaged tooth is the comparison most people need after the root canal discussion. The root canal service page covers the full process.