A baby tooth that turns grey after a bump or fall usually means the nerve inside the tooth has been bruised or has died, a process called pulp necrosis, and while it's not always an emergency, it should always be checked by a dentist. It's a common and understandably worrying moment for parents. One day your child bumps a front tooth on the coffee table or takes a tumble at the park, and a week or two later the tooth looks grey, or brown, instead of white. Here's what's actually happening, and what to do about it.
Key takeaways
- Grey discolouration after trauma is usually caused by blood breakdown products from a bruised or dying nerve seeping into the tooth's dentine.
- Colour change is often first visible around 10 to 14 days after the injury, though the final colour outcome can take months to become clear.
- A grey tooth doesn't automatically need root canal treatment, that decision depends on whether there are signs of infection, not colour alone.
- Watch for swelling, a pimple-like bump on the gum, or pain, these suggest infection and need prompt attention rather than a wait-and-see approach.
- Any dental trauma in a child should be assessed by a dentist promptly, even if the tooth looks fine at first.
- The tooth's long-term fate (keep, monitor, or extract) depends on how close it is to falling out naturally, not just its colour.
Why a bumped tooth turns grey
Inside every tooth is a soft core of nerve and blood vessel tissue called the pulp. A hard knock can bruise or damage this tissue, sometimes without any visible chip or crack on the outside of the tooth. When the blood supply to the pulp is disrupted, red blood cells break down and release compounds that seep into the tiny tubules of the dentine, the layer just under the enamel. This is what causes the grey, brown, or sometimes black tinge you see from the outside. It's essentially an internal bruise showing through the tooth.
The time-threshold rule for grey baby teeth
There's a useful rule of thumb here: colour change appearing within the first two to four weeks after an injury is common and doesn't automatically mean the tooth is dying or infected, it can reflect a bruised nerve that may still recover. But a tooth that stays grey for months, darkens further over time, or develops a grey colour alongside swelling or a gum boil, is more likely to indicate the nerve has died and needs a proper dental assessment to decide next steps.
| Timing and signs | What it likely means | What to do |
|---|---|---|
| Grey tint appears within 10-14 days, no pain or swelling | Likely early sign of a bruised nerve, may resolve | See a dentist for an initial check and monitoring plan |
| Colour stays grey or darkens over weeks to months | Possible pulp necrosis (nerve death) | Dentist assessment to check for infection, X-ray likely needed |
| Swelling, gum boil, or pain develops | Signs of infection needing attention | See a dentist promptly, don't wait it out |
| Tooth is grey but otherwise stable, close to natural loss age | May simply be monitored until it falls out naturally | Regular dental review, treatment only if infection signs appear |
Does a grey tooth always need root canal treatment?
No. This is one of the most common misconceptions parents have. Colour change alone isn't a reason to jump straight to root canal treatment or extraction. Dentists generally look for actual clinical signs of infection, such as swelling, a gum boil (parulis), pain on biting, or changes visible on an X-ray, before recommending treatment beyond monitoring. Some grey baby teeth stay discoloured but symptom-free right up until they fall out naturally with no treatment needed at all. Others do need attention if infection signs develop. This is exactly why a dental check after any trauma matters, rather than assuming a stable grey colour is automatically fine or automatically a problem.
What to do after a bump or fall
- See a dentist promptly after any trauma to a child's tooth, even if there's no visible chip and the child seems fine, some injuries only show up as colour change weeks later.
- Keep an eye on the tooth over the following weeks for swelling, a bump on the gum, or your child complaining of pain when chewing.
- Stick to a normal gentle brushing routine, avoid the temptation to scrub harder thinking it will change the colour, it won't.
- Offer softer foods for a few days if the tooth or gum is tender, without needing to eliminate any food group long-term.
- Keep any follow-up appointments recommended by your dentist, colour and symptoms can change over the following months.
How this differs from a permanent tooth injury
Baby teeth and adult teeth are managed a little differently after trauma, partly because a baby tooth has a limited lifespan and partly because there's a developing adult tooth underneath that needs protecting. If your child has also chipped a tooth in the same incident, our guide on what to do about a chipped baby tooth covers that separately. If the tooth was knocked out entirely rather than just discoloured, see our article on an avulsed baby tooth, and if it looks like it's been pushed up into the gum rather than knocked out, that's covered in baby tooth intrusion injuries. Older children with a permanent front tooth injury should see our guide on a chipped permanent front tooth.
Frequently asked questions
How long after a bump does a baby tooth turn grey?
Colour change is often first noticeable around 10 to 14 days after the injury, though it can take weeks to months for the final colour to settle and become clear.
Will a grey baby tooth go back to normal colour?
Sometimes, yes. Some teeth recover their normal colour over time if the nerve wasn't permanently damaged. Others stay grey permanently, and some darken further. A dentist can help monitor which direction things are heading.
Does a grey baby tooth mean it needs to be pulled out?
Not automatically. Many grey baby teeth are simply monitored and left to fall out naturally if there are no signs of infection. Extraction is usually only considered if there's active infection or other complications.
Is a grey tooth painful?
Not necessarily. Many children with a grey tooth have no pain at all. Pain, swelling, or a gum boil are the signs that suggest something needs attention.
Can I wait and see, or should I book straight away?
Any dental trauma in a child, including a bump that later causes discolouration, should be assessed by a dentist promptly rather than waiting, so any developing problem is caught early.
Could the colour change affect the adult tooth underneath?
In most cases the developing adult tooth is protected by bone and unaffected, but a dentist will check this as part of the assessment, particularly for more significant injuries.
What if my child seems fine and isn't complaining of pain?
Even without pain, it's worth having any traumatised or discoloured tooth checked, since infection can sometimes develop without obvious symptoms early on.
If your child has bumped a tooth or you've noticed a colour change, please don't wait it out. This article is general information and not a substitute for personal dental advice, and any dental trauma in a child should be assessed by a dentist promptly so it can be properly checked. The Lumi team can see your child for an assessment, book via our current offers or through our general dentist page.
