Root canal treatment: when you need it, how it works and what it costs

What having a tooth's nerve removed means, when it can no longer be avoided, how endodontic treatment with rotary instruments and the laser works, what pain is normal afterwards and what it costs for a molar.

When do you need root canal treatment?

Root canal treatment is needed when the pulp of the tooth, the soft tissue inside that is usually called “the nerve”, is inflamed beyond healing or infected. Once bacteria have reached the root canals, a filling can no longer stop them. The usual situations are:

• a deep cavity that has reached the pulp;
• pulpitis: pain that comes on by itself, wakes you at night or lasts for minutes on end after something cold or hot;
• an abscess: pain when biting, swelling of the gum or a small “pimple” on the gum that comes and goes;
• a dead pulp: the tooth doesn't hurt, but it has darkened or an X-ray shows an infection at the tip of the root.

When the cavity is deep but the pulp is still healthy, pulp capping, a protective layer placed over the pulp, can avoid the need for root canal treatment.

What having the nerve removed actually means

“Root canal”, “having the nerve out” and “endodontic treatment” all mean the same thing: the dentist removes the diseased pulp, cleans and disinfects the canals, then fills them and seals them tightly. The tooth stays where it is, anchored in the bone, and you carry on chewing with it. It no longer feels cold or heat and, over time, it becomes more fragile, mainly because of the tooth structure lost to decay, old fillings and the opening needed for the treatment. That is why the way it is restored afterwards matters so much.

How endodontic treatment works, step by step

1. Local anaesthetic. We only start once the tooth is completely numb.
2. The rubber dam. A thin rubber sheet isolates the tooth, so that saliva and the bacteria in it can't get into the canals.
3. Cleaning the canals. The dentist finds each canal, measures its length and cleans it with flexible FKG nickel-titanium rotary instruments that follow the curve of the root, rinsing it repeatedly with disinfecting solutions.
4. Laser sterilisation. The Er:YAG laser completes the disinfection in the fine side branches of the canals and in their walls, where instruments can't reach.
5. Filling the canals. The canals are filled and sealed right down to the tip of the root, and a check X-ray confirms the result.
6. Closing the tooth with a temporary filling or straight away with the final restoration.

How many visits it takes and whether it hurts

When the infection hasn't reached the bone, treatment is often completed in a single visit: about an hour for a front tooth and 60 to 90 minutes for a molar. When there is an abscess, the canals are usually filled temporarily with calcium hydroxide, a medicated dressing, and the treatment is completed at a second visit, one or two weeks later.

The treatment doesn't hurt: you only feel slight pressure, and the tiring part is keeping your mouth open for a long time. When the nerve is very inflamed, the anaesthetic is sometimes slower to take effect; the dentist tops it up and only carries on once you can't feel anything.

Pain after a root canal: what's normal and when to call us

Once the anaesthetic wears off, the tooth may be tender to bite on for two or three days, sometimes a week, and the tenderness eases from one day to the next. An ordinary anti-inflammatory (such as ibuprofen) or paracetamol helps, following the doses on the leaflet, if you have no contraindications. Until the final restoration, chew on the other side.

Call us if the pain gets worse after the third day instead of better, if swelling appears, if the tooth feels “higher” when you close your mouth or if the temporary filling has fallen out. A fever, swelling that grows quickly or difficulty swallowing or breathing mean a medical emergency: call 112 or go to the nearest hospital emergency department.

Why a treated molar often needs a crown

After a large cavity and the opening needed for treatment, a molar is often left with only thin walls, which can crack when you chew, even under a well-made filling. A crown covers the tooth all the way round, holds it together and seals it tightly, so that bacteria can't reinfect the canals. If very little of the tooth is left, a post and core is made first: a post fixed in the canal that supports the crown. Ideally, the final restoration is done within a few weeks of the treatment. For front teeth with solid walls, a filling is often enough.

Retreatment: when an old root canal has to be redone

Sometimes a tooth treated years ago starts to hurt, or an X-ray shows an infection at the tip of the root, usually because of an incomplete root filling or bacteria that have leaked in under old dental work. The old filling material is then removed from the canals, and the canals are cleaned again, sterilised with the laser and refilled. If retreatment isn't possible, there is a surgical option for front teeth and premolars: an apicoectomy. Extraction remains the last resort.

How much does root canal treatment cost for a molar?

The price depends mainly on the number of canals: front teeth usually have one, premolars one or two, and molars three or four.

For example, for a molar with three canals, the indicative calculation is: 3 canals × 350 lei = 1,050 lei, plus 250 lei for laser sterilisation, 70 lei for the anaesthetic and 80 lei for the rubber dam, making 1,450 lei. The final restoration is paid for separately: for example, a porcelain-fused-to-metal crown costs 1,050 lei and a ceramic crown on a zirconia framework 1,850 lei. You receive the exact price in your written plan, after the consultation and X-ray.

Frequently asked questions