Knocked-Out Tooth? Here's What to Do in the First 30 Minutes
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A stick to the mouth during a hockey game, a face-first landing off the monkey bars, a slip on an icy London sidewalk. A tooth can be knocked out, or avulsed, in a second, and what happens in the next half hour has a real effect on whether it can be saved.
Here is what to do, step by step, and what to expect at the dentist.
Key Takeaways
- If an adult tooth is knocked out, put it back in the socket right away if you can, holding it only by the crown.
- If you cannot, keep it moist in cold milk or the person’s saliva. Never let it dry out.
- Get to a dentist immediately. The less time the tooth spends out of the mouth, the better its chances.
- Never put a baby tooth back in, but do see a dentist promptly.
Why the First 30 Minutes Matter
The root of every tooth is covered in living cells called the periodontal ligament, the tissue that anchors the tooth to the jawbone. Once a tooth is out of the mouth, those cells start drying out within minutes.
According to the International Association of Dental Traumatology guidelines, published in the journal Dental Traumatology, most of these cells are no longer viable after about 30 minutes out of the mouth and dry. Teeth put back within roughly 15 minutes have the most favourable outlook, and teeth kept moist in a suitable liquid fare better than teeth left dry. The Canadian Dental Association notes that if help is reached within about 10 minutes, there is a fair chance the tooth will take root again.
So there are two goals: get the tooth back in or keep it wet, then get to a dentist fast.
First, Is It a Baby Tooth or an Adult Tooth?
This is the first decision, because the advice is completely different. Adult front teeth usually start coming in around ages 6 to 8. Before that, a knocked-out front tooth is most likely a baby tooth. If you are not sure, do not put it back. Place it in milk and call a dentist right away.
If It’s a Baby Tooth
Do not try to put a baby tooth back in. The international guidelines for injuries to baby teeth advise against it, because doing so can damage the adult tooth developing underneath.
Still book a dental exam for your child promptly. The dentist will check for other injuries, look at the developing adult tooth, and make sure a tooth you cannot find was not pushed up into the gum or swallowed.
Knocked-Out Tooth: What to Do, Step by Step
These steps are for an adult (permanent) tooth.
Step 1: Check for Serious Injuries First
If the person lost consciousness, hit their head, may have a broken jaw, is having trouble breathing, or is bleeding heavily, call 911 or go to the nearest emergency department first. The tooth can come along in a container of milk. Otherwise, keep the person as calm as you can and move to step 2.
Step 2: Pick the Tooth Up by the Crown
Find the tooth and hold it by the crown, the white part you normally see when someone smiles. Avoid touching the root, the longer, yellowish end. That is where the fragile cells live.
Step 3: Rinse Briefly Only If It’s Dirty
If there is dirt or debris on the tooth, rinse it gently for a few seconds, ideally in milk, saline, or the person’s own saliva. A quick rinse with cool water is fine if that is all you have. Do not scrub it, use soap, or wipe it with a tissue. If you are near a sink, close the drain first. Wet teeth are slippery, and drains are unforgiving.
Step 4: Put It Back in the Socket
Check which way the tooth faces by comparing it with the teeth beside the gap. Then guide it back into the socket with gentle finger pressure. Do not force it. Once it is in place, have the person bite gently on gauze, a clean handkerchief, or a folded napkin to hold it steady. Putting a tooth back is often less uncomfortable than people expect.
Step 5: If You Can’t Put It Back, Keep It Moist
Sometimes replanting is not possible, for example if the person is very young, dazed, or too upset. In that case, place the tooth in one of the following, listed in order of preference:’
- Cold milk
- A tooth preservation kit, if you have one on hand
- The person’s saliva, spat into a small cup
- Saline solution
Plain water is a poor choice, but it is still better than letting the tooth dry out. The Canadian Dental Association recommends milk whenever there is a chance the tooth could be swallowed.
Step 6: Get to a Dentist Right Away
Call the dental office on your way and bring the tooth with you. Note roughly when the injury happened, since your dentist will ask how long the tooth was out and whether it was kept moist. Bite on clean gauze to control bleeding, and use a cold compress on the outside of the lip or cheek for swelling.
If your dental office is closed, do not wait until morning. Seek urgent dental care that is open, or go to a hospital emergency department.
What Not to Do
- Do not hold the tooth by the root.
- Do not scrub it or clean it with soap, alcohol, or other products.
- Do not wrap it in tissue or let it dry out.
- Do not wait to see whether things settle down on their own.
Can a Knocked-Out Tooth Be Saved?
Often, yes, especially when it is handled quickly. The outlook depends on several factors:
- How long the tooth was out of the mouth and dry
- What it was stored in
- How developed the root is, since young teeth with still-growing roots can heal differently
- Whether there are other injuries to the tooth, gums, or jaw
The dental trauma guidelines describe the long-term outlook as poor when a tooth has been dry for more than 60 minutes. Even then, they note that putting the tooth back is almost always worth doing, because it keeps future options open and helps preserve the surrounding bone.
It is also worth knowing that some replanted teeth fuse to the bone or slowly break down over the years and may need to be replaced later. That is why follow-up visits matter so much.
What Happens at the Dental Office
Assessment and Imaging
Your dentist examines the tooth, gums, lips, and neighbouring teeth, then takes low-dose digital X-rays. In our London office, 3D CBCT imaging is also available when a closer look at the roots and surrounding bone is needed, for example to check for a fracture.
Replanting and Splinting
After local freezing, the tooth is cleaned gently and placed back in the socket, or its position is checked if you already put it back. It is then held in place with a flexible splint, a thin wire bonded to the injured tooth and its neighbours, usually for about two weeks. A longer splinting time may be needed if the jawbone was also injured.
Follow-Up Treatment
Adult teeth with fully formed roots usually need root canal treatment within about two weeks. Younger teeth with roots still developing are often monitored first, since they can sometimes heal on their own. Your dentist may also prescribe antibiotics and ask about your tetanus coverage. If you feel anxious, let the team know; nitrous oxide (laughing gas) is available.
At home, expect soft foods for up to two weeks, gentle brushing with a soft toothbrush, and a break from contact sports. Follow-up visits continue through the first year and then yearly for several years.
If the Tooth Can’t Be Saved
When a tooth cannot be saved, or is lost later, there are several ways to replace it, including a dental implant, a bridge, or a partial denture. Implant planning in our office uses 3D CBCT imaging to assess the bone before treatment. For teens, implants are usually postponed until jaw growth is complete, so your dentist will talk through temporary options that hold the space in the meantime.
How to Lower the Risk
A few habits go a long way:
- Wear a mouthguard for hockey, soccer, basketball, lacrosse, and skateboarding. The Canadian Dental Association notes that custom-fitted mouthguards made by a dentist fit better than stock or boil-and-bite versions.
- Use car seats for young children and properly adjusted seat belts for everyone else.
- Skip chewing ice and hard candy, and use scissors instead of your teeth.
- Keep a small tooth preservation kit in the family sports bag or first aid kit.
Frequently Asked Questions
Can a knocked-out tooth be saved?
Often, yes, if it is an adult tooth that is put back in the socket or kept moist and brought to a dentist quickly. The less time it spends out of the mouth and dry, the better its chances.
How long can a tooth be out of the mouth and still be saved?
Teeth replanted within about 15 minutes have the most favourable outlook, and most root cells are no longer viable after about 30 minutes of drying. Milk buys valuable time, but get to a dentist right away.
Should I put a knocked-out baby tooth back in?
No. Putting a baby tooth back can damage the adult tooth developing underneath. Keep your child calm, control any bleeding, and book a dental visit promptly.
Is a knocked-out tooth a dental emergency?
Yes. A knocked-out adult tooth is one of the few true dental emergencies, and every minute counts. If there is also a head injury, trouble breathing, or bleeding that will not stop, seek emergency medical care first.
Fast Help When Every Minute Counts
A knocked-out tooth is stressful, but a calm, quick response gives it a much better chance. Hold it by the crown, put it back or keep it in milk, and get to a dentist right away.
At We Smile Dentistry, we offer same-day emergency appointments when available, and we see patients of every age, from toddlers after a playground tumble to adults after a rough game. Save our number in your phone today so it is ready if you ever need it. If you or someone in your family has just injured a tooth, contact our London, Ontario team now.
This content is for informational purposes only and is not a substitute for professional dental advice, diagnosis, or treatment. For personalized care, please book a consultation with Dr. Spagnuolo at We Smile Dentistry by calling 519-661-0042 or visiting wesmiledentistry.ca/contact.