A root canal that is properly restored usually lasts more than ten years, and many last the rest of the patient’s life. Large studies of treated teeth generally report survival above eighty five percent at eight to ten years. The variable that decides which side of that figure your tooth falls on is not the root canal itself. It is what gets put on top of it, and how quickly. The American Association of Endodontists sets out what the treatment itself involves; this guide covers what happens after it.
That is the part most people are not told clearly. A perfectly executed root canal under a temporary filling for eight months is a tooth heading for extraction. An average root canal under a crown fitted three weeks later is a tooth you will probably still have in twenty years.
Why the Crown Matters More Than the Root Canal
A root canal removes the nerve and blood supply from inside the tooth. That stops the pain and clears the infection, but it also leaves the tooth without its internal supply, and over time the remaining structure becomes more brittle. Add to that the hole drilled through the top to reach the canals, and a back tooth is left considerably weaker than it looks.
A crown wraps the remaining tooth and holds it together so that biting force is spread rather than concentrated on a weakened wall. Without one, a molar can split vertically, and a vertical root fracture is the one complication that cannot be repaired. The tooth comes out. That single failure mode is behind a large share of root canals that people describe as having failed, when in fact the root canal worked and the tooth broke.
Front teeth are treated differently. An incisor with a small access hole and otherwise intact walls is often restored with a filling rather than a crown, because it takes less force and has more of itself left.
What Shortens the Life of a Root Canal Treated Tooth
- A delayed or missing crown. The single largest cause. Temporary fillings are designed to last weeks, not months, and they leak.
- New decay at the margin. A treated tooth cannot ache to warn you, so decay under a crown edge can advance a long way before it is noticed.
- A missed canal. If a canal was never found, the tissue inside it stays infected, and the tooth can flare up years later.
- A crack that was already there. A tooth that cracked before treatment may continue to split afterwards.
- Grinding and clenching. Sustained overnight force is hard on a tooth that has lost its internal structure.
- Coronal leakage. If the seal at the top fails, bacteria travel back down the filled canal and re-infect the root tip.
Notice how many of those are about the top of the tooth rather than the root. The root filling is usually the durable part.
How to Tell if a Root Canal Is Failing
A treated tooth has no nerve, so the warning signs are different from ordinary toothache and are easy to dismiss.
- Tenderness when you bite on that specific tooth, months or years after it settled.
- A dull ache or pressure in the gum above or below it.
- Swelling in the gum, or a small pimple that appears, drains and returns.
- The tooth darkening compared with its neighbours.
- A bad taste that keeps coming back from one spot.
None of these mean the tooth is lost. Caught early, most are fixable. Left for a year, the options narrow.
Can a Failed Root Canal Be Redone?
Usually, yes. Retreatment involves removing the crown or filling, taking out the old root filling material, cleaning the canals again including any that were missed the first time, and resealing. It takes longer than the original treatment, which our guide to how long a root canal takes explains, and it costs more, but it saves the tooth.
Where retreatment is not possible, usually because of a vertical fracture, the tooth is extracted and replaced with an implant or a bridge. That route works, and it costs several times what retreatment would have. Our comparison of root canal versus extraction sets out the numbers on both paths.
How to Make a Root Canal Last as Long as Possible
- Get the permanent restoration fitted promptly. Within a few weeks, not whenever it becomes convenient. If cost is the reason for the delay, say so, because a payment arrangement is cheaper than an extraction.
- Keep the margin clean. The join between crown and tooth is where decay starts. Floss it.
- Wear a nightguard if you grind. Worn flat edges or morning jaw ache are the giveaways.
- Do not test it. Ice, bottle tops and nutshells break healthy teeth, let alone treated ones.
- Keep your checkups. A treated tooth cannot tell you it has a problem, so someone has to look. An x-ray every couple of years shows the root tip healing, or not.
Root Canals and Restorations at Elephant Dental Kiambu
We are on Biashara Street in Kiambu town, open eight to five every day of the week including Sundays. If you have had a root canal elsewhere and never got the crown, or you have a treated tooth that has started aching again, that is worth an x-ray before it becomes an extraction.
WhatsApp or call 0143 178126 to book. Bring the date of the original treatment if you know it.
Frequently Asked Questions
Do root canals last forever?
Many last a lifetime, but no dental treatment carries a guarantee. Studies typically report survival above eighty five percent at eight to ten years, and a properly crowned tooth that is kept clean often goes far beyond that.
Do I really need a crown after a root canal?
On a back tooth, almost always. Molars and premolars take heavy biting force and split without one. A front tooth with intact walls can often be restored with a filling instead.
Can a root canal fail years later?
Yes. The usual causes are a canal that was missed at the time, new decay at the crown margin, or a seal that has started leaking. Biting tenderness and a recurring gum swelling are the signs to act on.
Why did my root canal tooth go dark?
Discolouration is common after the nerve is removed and is not by itself a sign of failure. It can be treated with internal bleaching or covered with a crown or veneer.
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