This article is general information for our patients, not a diagnosis. If something in your mouth hurts, changes, or worries you, have it examined.
People often want a straight yes or no before I’ve even looked, and I get it. But whether a tooth can be saved isn’t a call I can make from a glance, an X-ray alone, or how much it hurts. No single finding decides it. What settles it is reading everything at once — what’s genuinely left once I’ve cleaned the tooth out, how much bone holds it, what the X-ray shows at the root, and the job that tooth does for you. Any one of those can point one way and be overruled by the rest, which is why the real answer comes in the chair. Here’s how I think it through.
The three things I weigh
When a tooth is badly broken down or infected, I work through three questions together, roughly in this order:
- Restorability — is there enough solid tooth left to rebuild?
- Support — is there enough healthy bone holding it in?
- Strategic value — is the tooth worth the effort where it sits?
A root canal cleans infection out of the hollow inside of the tooth so you keep your own root; an extraction removes it completely and leaves a gap to plan around. Neither is automatically better — the right one is whichever your particular tooth can actually support.
Is there enough tooth left to rebuild?
“Restorable” means enough solid tooth remains to hold a lasting crown (a cap over the whole tooth) once the decay and old filling are cleared away. Here’s what most people miss: a root canal treats the inside of the tooth and does nothing for the outside walls. Afterwards the tooth still needs a strong cap — a full crown, or a partial one (an onlay) on a back tooth — or it can crack under chewing. With nothing left to anchor that cap, the root canal is wasted effort.
The first thing I look for is a continuous ring of solid tooth standing above the gum that a crown can grip all the way around, like a collar (a ferrule). As a rough guide it needs to be about 2 mm tall and complete right around to hold long-term. A good ring gives a tooth a real chance; a break running below the gum, with no ring at all, is often not restorable however good the root canal.
I often can’t give a final answer before I start, because the damage tends to be bigger than it looks: a tooth can seem reasonable, then once the soft decay and a leaking old filling come out, turn out to be a thin shell. I’d rather tell you that than rebuild something likely to fail within a year.
Is there enough bone to hold it?
A tooth needs healthy bone around it to stay firm, however well the root canal goes — and the root canal does nothing for that foundation. Think of a fence post: the post can be perfect, but if the ground around it has washed away it still wobbles and eventually fails. So I check how much bone surrounds the root, whether the tooth is loose, and whether there are deep pockets where the gum has pulled away from the tooth. As a benchmark, a tooth that’s lost more than about half its bone support, or that’s noticeably loose, is a much weaker candidate — crowning it then is building on sand.
Is the tooth worth saving where it sits?
Not every tooth carries the same workload, and where it sits changes how hard I’ll fight for it — what dentists call a tooth’s strategic value. A back tooth (molar) doing most of the chewing on one side, or one anchoring a bridge or denture, earns more rescue effort; a crowded or spare tooth that nothing depends on may not be worth a complex rescue.
Your own circumstances belong here too, and I’d rather talk about them openly: how much treatment you’re up for, your general health, how the costs fall, and whether coverage like the Canadian Dental Care Plan applies. A plan only works if it’s one you can see through — including the follow-up crown.
When taking the tooth out is the better call
Removal is the honest answer when the tooth is split down the root, broken too far below the gum to rebuild, or when a repeat root canal keeps failing. Pushing to save it then tends to mean more visits, more cost, and the same gap a year later. The clearest examples:
| Situation | Why saving it usually doesn’t work |
|---|---|
| Crack running vertically down the root | The split is a permanent doorway for bacteria; no crown or filling seals it |
| Break or decay reaching below the gum and bone | Nothing solid above the gum for a crown to grip around |
| A re-done root canal that keeps re-infecting | Each repeat attempt is less likely to work than the last |
| Severe gum-disease bone loss with a loose tooth | The foundation is gone, so even a perfect root canal stays wobbly |
| The root being eaten away from inside or out (root resorption) | The tooth is dissolving and can’t be rebuilt predictably |
The odds explain the pattern. A first-time root canal works in roughly 80–90% of cases — nearer 90% before the infection reaches the bone at the root tip, nearer 80% once it has. A re-done one works in about 70%, and once the inside of the root has been damaged by earlier attempts (a ledge or blockage that stops us cleaning its full length), success falls to just under half. That slope is why I won’t chase a failing tooth forever.
A vertical root fracture is the one I most hate to find: a crack running lengthways down the root can’t be glued, filled, or crowned back to health. Removing the tooth is genuinely the better path then, not a failure to try.
Are root canals bad for you?
No — there’s no sound evidence that a properly treated tooth causes illness elsewhere in your body. The worry traces to a 1920s idea, the “focal infection theory,” which claimed bacteria sealed inside a treated tooth could leak out and cause disease; that research was poorly designed and has been disproved many times since, and the American Association of Endodontists and modern reviews are clear there’s no link to cancer or disease elsewhere.
The real problem is the opposite — leaving a dead, infected tooth in place. A dying nerve becomes a pocket of bacteria that can flare into an abscess, a painful, sometimes swollen infection at the root tip, and a root canal removes it. If you’d like the detail, I cover what actually happens during a root canal and what a dental abscess feels like separately. Today’s root canals are done with the tooth sealed off from saliva under a thin rubber sheet and cleaned with disinfecting rinses — a long way from the procedures those old claims grew out of.
Why keeping your own tooth is usually worth it
Your natural tooth has its own root, its own bone support, and a feel for biting that no replacement fully copies, so I lean toward saving it when I can. A tooth that’s had its nerve removed loses a little of that fine pressure sense, but it still chews well and keeps the surrounding bone active.
The numbers back up trying. Root-canalled teeth that get a proper crown soon afterward tend to survive around 8 or 9 out of 10 over about ten years — good odds, not a certainty, and they depend on you keeping up with cleaning and check-ups. Timing matters more than people expect: in one eight-year study from the European Society of Endodontology, back teeth left under just a temporary filling were lost about three times as often as those crowned within four months. So if we save it, don’t put off the crown — that step is half the reason it works.
If the tooth does need to come out
If a tooth has to go, the gap becomes part of the plan from day one, because an empty space lets neighbouring teeth tip and the opposite tooth drift down. The removal is usually quicker than people expect: once the area is fully frozen (local anaesthetic) you shouldn’t feel anything sharp, though you’ll feel firm pressure and pushing as the tooth comes out — that part is normal. Expect a few sore days, with clear aftercare instructions to take home. The main routes for filling the space are an implant, a bridge, a partial denture, or leaving the gap and keeping an eye on it, which is sometimes reasonable — each with its own timeline and trade-offs, which I walk through in your options for replacing a missing tooth.
The bottom line
With enough solid tooth and healthy bone, I lean toward saving it with a root canal and a crown — your own tooth is hard to beat. When it’s cracked down the root, broken below the gum, or sitting in too little bone, taking it out and replacing it well tends to be the better plan. Side by side:
| Saving it (root canal + crown) | Taking it out (extraction + replacement) | |
|---|---|---|
| What you keep | Your own root, the bone around it kept active, your natural bite feel | Nothing of the tooth — the gap needs its own plan |
| What it needs | About 2 mm of solid tooth above the gum, healthy bone, and a crown within roughly four months | Healing time, then an implant, bridge, partial denture, or a watched space |
| When it fits | The tooth is restorable and its foundation is sound | Vertical root crack, break below the gum, repeated failed root canals, or severe bone loss |
Which side of that line your tooth falls on isn’t something to settle from symptoms or a photo — it takes an exam, an X-ray, and a clear conversation, read together. This article is part of our Adult Patient Information library, alongside guides to root canals, extractions, and tooth replacement.
If you’re weighing a root canal against an extraction, or you’re in pain and unsure which way it’s heading, call us or use our contact page to book an exam. We’ll take a proper look, explain what your tooth can and can’t support, and help you make the right call.
