Root canal treatment explained: each visit, the crown after, and what to ask

“You need a root canal” is one of the least welcome sentences in a dental clinic, mostly because of its reputation. The treatment itself is far less dramatic than its name. It is a way of saving a tooth whose inside has become inflamed or infected, so that you keep the tooth rather than lose it.

This article explains what a root canal treatment does, what happens at each visit, why a crown usually follows, and what to ask about cost. It does not replace your dentist’s advice about your own tooth.

What is actually inside a tooth

A tooth has a hard outer shell (enamel and dentine) and, in its centre, a soft core called the pulp: nerves and blood vessels that run down narrow channels in each root. These channels are the root canals. A front tooth usually has one, a premolar one or two, and a molar three or four.

When decay goes deep, a crack lets bacteria in, or a tooth takes a hard knock, the pulp can become inflamed. If the inflammation cannot settle, the pulp dies and the space becomes infected. The infection can spread out of the tip of the root into the bone, which is where an abscess comes from.

Signs that a tooth may need one

Only a dentist can tell, usually with an X-ray, but these are the common reasons people end up in the chair:

• Pain to hot or cold that lingers for a minute or more after the drink has gone.
• Pain when biting or pressing on the tooth.
• A throbbing ache that wakes you at night.
• Swelling of the gum near the tooth, or a small pimple on the gum that comes and goes.
• A tooth that has darkened after an injury.

Sometimes there are no symptoms at all and the problem is found on an X-ray.

What happens at each visit

Every dentist works a little differently, but a typical root canal treatment looks like this:

First visit. The dentist takes an X-ray, numbs the area with a local anaesthetic, and places a thin rubber sheet around the tooth to keep it dry and clean. A small opening is made in the top of the tooth to reach the pulp. The infected or inflamed tissue is removed, and the canals are cleaned, shaped with fine instruments, and washed out. If the treatment continues at a later visit, a medicine is placed inside and the opening is sealed with a temporary filling.

Second visit, and sometimes a third. Once the canals are clean and the tooth has settled, they are filled with a rubber-like material and sealed. Another X-ray checks that the filling reaches the end of each root. The top of the tooth is then built up with a filling, often called a core.

The crown. For most back teeth, the dentist will recommend a crown: a cap that covers the whole tooth. The tooth is shaped, an impression or scan is taken, and the crown is made in a dental lab and fitted at a later visit.

Some dentists complete the canal treatment in a single sitting when the tooth allows it. Neither approach is automatically better; it depends on the tooth.

Why the crown matters

A tooth that has had a root canal has lost its pulp and a good deal of its structure, from the original decay and from the opening made to reach the canals. It becomes more brittle. A back tooth takes heavy chewing forces, and without a crown it can crack, sometimes in a way that cannot be repaired.

Until the crown is fitted, avoid chewing hard food on that side. Many root canals that fail do so because the tooth broke while waiting for its crown.

What the cost depends on

Root canal treatment is usually quoted per tooth, and two quotes can look very different. These are the things that move the price:

• Which tooth. A molar with three or four canals takes longer than a front tooth with one.
• How complicated the canals are. Curved, narrow or blocked canals take more time.
• X-rays. Whether they are included in the quote or billed separately.
• The crown. Often quoted separately from the root canal. Metal, ceramic fused to metal and all-ceramic or zirconia crowns differ in price and appearance.
• A redo. Re-treating a tooth that has had a root canal before is usually harder, and priced accordingly.

Ask for a written plan that names the tooth, says whether the crown is included, and names the crown material. The plan you are given is what the final bill should match.

Keep the X-rays and the plan. If you move cities or change dentists, the next dentist will want to see what was done and when. A health record on your phone, such as your 92health record, keeps every prescription and visit summary together.

Root canal or extraction?

When a tooth can be saved, keeping it is usually the better outcome. A removed tooth leaves a gap, and the teeth on either side tend to drift into it. Filling the gap means an implant, a bridge or a denture, each of which costs more and takes longer than a root canal and crown.

There are teeth that cannot be saved: those with a crack running down the root, too little tooth left to restore, or severe gum disease around them. For those, removal is the right choice, and your dentist will explain why.

After the treatment

• Some soreness for a few days is normal.
• Take only the medicines your dentist prescribes, as they prescribe them.
• Avoid chewing hard on the tooth until the crown is fitted.
• Brush and floss as usual.
• Go back for the review your dentist asks for. A follow-up X-ray months later shows whether the bone around the root has healed.

Call your dentist if the pain gets worse after two or three days, the swelling increases, you develop a fever, or the temporary filling falls out.