When a tooth hurts badly, many people’s first thought is to have it out, because that seems quicker and simpler. But if the root is healthy and the tooth can be rebuilt, root canal treatment is usually the better choice: you keep your own tooth, whereas an extraction often has to be followed by a bridge, an implant or a denture. The choice of root canal vs extraction depends on the condition of the tooth, root and bone, and on your wishes.
What is root canal treatment, and can a tooth live without its nerve?
Inside every tooth is soft tissue known as the pulp, which most people call the nerve. Deep decay, a crack, a knock or a leaking filling can inflame or infect the pulp, and bacteria can then spread to the bone around the tip of the root.
Root canal treatment removes the inflamed or infected pulp and cleans, disinfects and seals the canals so that bacteria cannot get back in. The tooth is then restored with a filling or a crown (a cap). You may also hear it called a root filling, ‘having the nerve out’ or ‘killing the nerve’.
A fully developed tooth can survive without its pulp, because the tissues around the root keep nourishing it, as the American Association of Endodontists (AAE) explains. So even a ‘dead tooth’, whose nerve has died, does not automatically have to come out, although it usually needs treatment.
Our root canal treatment page explains the procedure step by step.
Root canal vs extraction: when saving the tooth is better
The decision is made after an examination, tests and an X-ray. Root canal treatment usually makes sense when:
- the root is intact and not cracked
- after cleaning, enough healthy tooth remains for a filling or crown, with a post in the canal if needed
- there is enough healthy bone around the root and the tooth is not loose
- you need the tooth for chewing or for the look of your smile
- you can attend every appointment, including the one for the permanent filling or crown
Why keeping the tooth is usually better
An extraction alone is quick and costs less at first. But the missing tooth often needs replacing, which means more visits and usually costs more than root canal treatment with a suitable permanent filling or crown (AAE, Cleveland Clinic):
- A bridge. A conventional bridge rests on the teeth either side of the gap, which are filed down for it, and the tissue removed does not grow back. It is usually made a few months after the extraction, once the gum and bone have healed.
- An implant. This needs surgery, then usually 3–6 months of healing before the crown is fitted.
- A partial denture. A removable option that many people find less comfortable than a fixed one.
- No replacement. Over time, neighbouring teeth may drift into the gap.
When extraction is the better decision
‘Save the tooth’ does not mean every tooth can or should be kept. Extraction is usually recommended when:
- the tooth has broken deep below the gumline, or the root is cracked along its length
- decay has left too little of the tooth to hold a filling or crown
- there is not enough bone around the root, for example because of advanced gum disease
- the infection returns even after retreatment, and other options are not suitable
It is also a personal decision. Once you have heard the benefits, risks and costs of each option, you can still choose extraction – as an informed choice, not out of fear or in a hurry. Read more about tooth extraction and wisdom tooth removal.
When a root-filled tooth hurts again: retreatment, post and crown
If a root-filled tooth hurts again, or an X-ray shows infection, that does not automatically mean extraction. Root canal treatment can fail because of a missed canal, a filling or crown that leaks or was placed too late, new decay or a crack (AAE).
There are then three options:
- Retreatment. The old root filling is removed, and the canals are cleaned, disinfected and refilled.
- Surgery at the root tip (an apicectomy), if the infection persists after treatment.
- Extraction, if the tooth cannot be saved any other way.
A badly damaged tooth with a healthy root can sometimes be rebuilt with a post in the canal and a crown, if enough sound tooth remains.
How long does a root-filled tooth last? What the studies show
No treatment lasts for ever. In a systematic review, 86–93% of root-filled teeth were still in the mouth 2–10 years after treatment. In a large UK study of treatment by dentists in postgraduate endodontic training, about 95% of teeth were still in place four years after a first treatment or a retreatment (Ng and colleagues, 2011).
These are averages, not a promise for any one tooth. In the review, teeth were more likely to survive when they:
- had a crown fitted after treatment
- had neighbouring teeth on both sides
- were not supporting a bridge or a removable denture
- were not molars (the large back teeth)
In the UK study, teeth were lost more often in people with diabetes or on long-term steroids (corticosteroids), so tell your dentist about any health conditions and medicines you take.
Regular brushing, cleaning between your teeth and check-ups also help, so that new decay is spotted early.
Root canal myths and facts
Myth: ‘A dead tooth has to come out’
A tooth without a living nerve usually needs treatment, because untreated infection can cause pain, an abscess and bone damage. But with well-cleaned canals and a timely permanent filling or crown, it can keep working for many years.
Myth: ‘A root-filled tooth makes you ill’
There is no credible scientific evidence that root canal treatment causes cancer, heart disease, arthritis or other illnesses. The idea comes from the early 20th-century ‘focal infection’ theory, which was later discredited (AAE).
Myth: ‘Antibiotics will cure the tooth’
Antibiotics do not remove the infected pulp, and a Cochrane review found too little evidence that they ease the pain of an inflamed nerve. They may be prescribed when infection is spreading, but alongside treatment, not instead of it.
Myth: ‘Once it stops hurting, there’s no need to finish’
A temporary filling is only a short-term measure: it can leak or break, and the weakened tooth can crack. Delaying the permanent filling or crown is a recognised reason for root canal treatment to fail.
When to see a dentist
Book an appointment if you notice:
- severe pain when you bite or chew
- sensitivity to hot or cold that lingers afterwards
- a small pus-filled spot on the gum (a gum boil or fistula), or swelling of the gum
- a tooth that has darkened
- pain spreading to your jaw, face or neighbouring teeth
- a broken tooth or a lost filling
- pain after root canal treatment that gets worse or lasts longer than a week
Waiting often makes the problem more complicated, and sometimes the tooth can no longer be saved. For severe pain or a broken tooth, ask for a same-day appointment during opening hours, when one is available. Outside opening hours, contact the public out-of-hours dental service. Our toothache guide explains what to do in the meantime.
If you have difficulty breathing, speaking or swallowing, severe swelling inside your mouth, swelling around your eye, problems with your vision, or you cannot open your mouth, do not wait for a dental appointment: call 194 (ambulance) or 112 (European emergency number), or go to hospital straight away (NHS). Outside North Macedonia, call your local emergency number.
‘Save the tooth’: what it means at our practice
‘Save the tooth’ is the motto of the Dr. Milanovski practice. As the practice’s own description puts it, saving existing natural teeth comes first.
So before we talk about extraction, we first check whether the tooth can be saved and whether that makes sense for you. Dr Kiril Milanovski explains the options, with their benefits and limitations, and the decision is yours. If a tooth cannot be saved, we tell you so openly.
On its online profiles, the practice shows root canal treatment and retreatment, treatment of infected roots (root gangrene), and weakened teeth rebuilt with a titanium post and a metal-ceramic (porcelain bonded to metal) crown.
Root canal treatment: frequently asked questions
Does a root canal hurt?
It is done under local anaesthetic, and most people say it feels much like having a filling. A very inflamed tooth sometimes needs extra anaesthetic, so tell us if you can still feel pain. Mild tenderness for a few days afterwards is common. If pain after the root canal gets worse or has not settled after about a week, please call us.
Is it better to have the tooth taken out than to have a root canal?
If the tooth can be treated and restored, it is usually better to keep it. If it cannot be repaired, extraction is the right choice.
How long does a tooth last after a root canal?
No one can predict exactly how long a tooth will last. In studies, most root-filled teeth are still in the mouth 2–10 years later, and with a timely permanent filling or crown, good care and check-ups, they can last many years.
Do you need a crown after a root canal?
Often, yes, especially for back teeth (molars), because root-filled teeth with a crown are more likely to stay in the mouth. But not always: a front tooth with little damage sometimes needs only a filling. Read more about dental crowns.
Why does a tooth turn dark after a root canal?
A grey or darkened tooth can mean the nerve has died, often after a knock. Teeth also sometimes change colour after root canal treatment (Cleveland Clinic). The dentist first checks the cause and may then suggest whitening, a composite veneer or a crown.
If you are not sure whether your tooth can be saved, book an examination. Afterwards you will know your options and their risks, and you will receive a written plan with the cost before you decide.
Sources
- American Association of Endodontists – What is a root canal?
- American Association of Endodontists – Myths about root canals
- American Association of Endodontists – Endodontic retreatment
- Ng Y-L, Mann V, Gulabivala K. A prospective study of the factors affecting outcomes of nonsurgical root canal treatment, part 2: tooth survival. Int Endod J 2011;44:610–625
- Cochrane – Antibiotic use for irreversible pulpitis (CD004969, 2019)
- Cleveland Clinic – Dental bridges
- Cleveland Clinic – Tooth discoloration
- NHS – Dental abscess (when to seek emergency care)