Root Canal: The Tooth-Saving Treatment

At a Glance

• What it is: cleaning, disinfecting and sealing the inside of a tooth whose nerve is infected or badly inflamed.
• Visits: usually one or two, under local anaesthetic.
• Comfort: pain is usually worst before treatment and falls quickly afterwards.
• Afterwards: most back teeth need a crown or a strong restoration.
• The alternative: taking the tooth out, then living with the gap or replacing it with a bridge, denture or implant.

What Is Happening Inside the Tooth

Every tooth has a soft core of nerve and blood vessels called the pulp. Deep decay, a crack or an old leaking filling can let bacteria reach it. Once the pulp is badly inflamed or infected it cannot heal on its own, and the infection can spread to the bone at the tip of the root.

Signs include pain that lingers after hot or cold, pain on biting, a tooth that has darkened, swelling, or a pimple on the gum. Sometimes there are no symptoms at all and the infection shows up first on an X-ray.

What the Research Says About Comfort

Root canal treatment has a reputation it does not deserve. A systematic review of 72 studies found that around 81% of patients had pain before treatment, around 40% a day after, and around 11% a week after, with pain falling to minimal levels by the end of that week (Pak & White, 2011).

In other words, the treatment usually relieves the pain rather than causing it. We use profound local anaesthesia, check you are numb before we start, and give you a clear plan for the few days afterwards.

Save the Tooth or Replace It?

It is a fair question, and the research gives a useful answer. A systematic review comparing restored root-treated teeth with single-tooth implants found no significant difference in how long they survived, and concluded the choice should rest on other factors (Iqbal & Kim, 2007).

Those other factors usually favour keeping your own tooth when it can be predictably restored: no surgery, no bone healing time, usually lower cost, and your natural tooth stays where it is. When a tooth cannot be predictably saved, for example because a crack runs down the root or too little tooth is left, we will tell you plainly and talk through the alternatives.

Why the Crown Matters

A root-treated back tooth is more brittle than it was, and the restoration on top matters as much as the root filling. In one study, root-treated back teeth that were not crowned were lost about six times as often as those that were (Aquilino & Caplan, 2002).

Not every tooth needs a crown. A front tooth with most of its structure intact may do well with a bonded filling. We will tell you which applies to your tooth, and why.

What to Expect

• 1. Settle the pain. Diagnosis, digital imaging and relief as our first priority.
• 2. Clean and seal. The infected space is gently cleaned, disinfected and sealed over one to two calm, fully anaesthetised visits.
• 3. Protect the tooth. A root-treated tooth usually needs a crown or strong restoration so it can chew confidently.

Does a Root-Treated Tooth Affect the Rest of the Body?

Claims that root-treated teeth cause illness elsewhere trace back to the "focal infection" theory of the early 1900s, which later research did not support. Endodontic organisations state there is no valid evidence that root canal treatment causes disease elsewhere in the body (American Association of Endodontists, 2023).

The bigger concern is the opposite: leaving an infection at the root tip untreated. Research has linked chronic root-tip infection with cardiovascular disease, although an association does not prove one causes the other (Berlin-Broner et al., 2017). Treating the infection, whether by root canal treatment or extraction, aims to remove it.

Finding the Cause, and When We Refer

Deep decay and cracked teeth have causes. Cracks often trace back to night-time grinding, and repeat decay to diet, dry mouth or brushing habits, so we look for the cause as well as fixing the tooth.

Some teeth have unusually complex or blocked canals, or need an old root filling redone. Where that is in your best interest, we refer you to an endodontist, a registered specialist in root canal treatment.

The research behind this page

• Pak JG, White SN. Pain prevalence and severity before, during, and after root canal treatment: a systematic review. Journal of Endodontics, 2011.
• Iqbal MK, Kim S. For teeth requiring endodontic treatment, what are the differences in outcomes of restored endodontically treated teeth compared to implant-supported restorations? International Journal of Oral & Maxillofacial Implants, 2007.
• Aquilino SA, Caplan DJ. Relationship between crown placement and the survival of endodontically treated teeth. Journal of Prosthetic Dentistry, 2002.
• Berlin-Broner Y, et al. Association between apical periodontitis and cardiovascular diseases: a systematic review of the literature. International Endodontic Journal, 2017.
• American Association of Endodontists. Root canal safety (fact sheet), 2023.

Inline Smiles Dental & Orthodontics. Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner. This page is general information only, not a diagnosis or a personal treatment recommendation. Research findings describe groups, and individual results vary; suitability for any treatment is assessed individually.