A Knocked-Out Tooth Can Be Saved

Having a tooth knocked out is one of the most alarming dental emergencies you can experience. It happens fast — a blow to the face during sport, a fall, an accident — and suddenly you're holding a tooth in your hand, or searching the ground for one. It's a frightening situation, and most people have no idea what to do.

Here's the good news: a knocked-out permanent tooth can often be successfully reimplanted if you act quickly and handle the tooth correctly. The critical factor is time. The cells on the root surface of the tooth — the periodontal ligament cells — begin to die within minutes of the tooth leaving its socket. The sooner the tooth is back in place, the better the chances of it reattaching and surviving long-term.

In my experience, the patients who have the best outcomes are the ones who knew what to do before it happened. That's why I'd encourage you to read through this guide even if you're not currently dealing with an emergency — knowing these steps could save your tooth, or your child's tooth, in the future.

What to Do Immediately: Step by Step

The first few minutes after a tooth is knocked out are the most important. Here's exactly what to do:

Step 1: Find the Tooth

This sounds obvious, but in the chaos of an accident it's easy to overlook. Search the area carefully. If the tooth has been knocked out during sport, ask someone to help you look. Check inside the person's mouth as well — sometimes a tooth is displaced or pushed into the gum rather than completely knocked out.

Step 2: Pick It Up by the Crown

Hold the tooth by the crown — that's the white part you normally see in the mouth. Never touch the root. The root is the pointed, yellowish part that's normally hidden inside the gum and jawbone. It's covered with periodontal ligament cells that are essential for the tooth to reattach. Handling, squeezing, or scrubbing the root damages these cells and dramatically reduces the chance of successful reimplantation.

Step 3: Clean It Gently (If Necessary)

If the tooth is visibly dirty (it fell on the ground, for example), rinse it very briefly under cold running water — no more than 10 seconds. Hold it by the crown and let the water run over the root. That's all.

Do not:

Scrub the root or use a brush
Use soap, disinfectant, alcohol, or any cleaning solution
Wrap the tooth in tissue or cloth (this dries out the root cells)
Handle the tooth more than absolutely necessary

Step 4: Try to Reimplant It Yourself

This is the single best thing you can do, and most people don't realise they can attempt it themselves. If the person is conscious, cooperative, and old enough to understand (generally over about 12), try gently pushing the tooth back into its socket.

Orient the tooth correctly — the smooth, curved side faces outward (toward the lip or cheek), and the concave side faces the tongue.
Push it in gently but firmly with your fingers. It doesn't need to be perfect — just getting it back in the socket is what matters.
Once it's in, have the person bite down gently on a clean cloth, handkerchief, or piece of gauze to hold it in place.
Get to my practice (or the nearest dentist) immediately.

Don't force it. If the tooth won't go back in, or if the person is too distressed or injured to cooperate, move to the next step.

Step 5: Store the Tooth Properly (If You Can't Reimplant It)

If reimplanting the tooth isn't possible, you need to keep it alive during transport to the dentist. The root cells must stay moist and in a compatible solution.

Best options, in order of preference:

Tooth-preservation solution (e.g., Hanks' Balanced Salt Solution) — if you have a tooth-saving kit, use it. These are available from pharmacies and are ideal for sports clubs to keep in first-aid kits.
Cold milk — this is the best readily available option. Milk has a pH and chemical composition that's compatible with the root cells and keeps them alive for up to an hour or more.
The person's own saliva — have them spit into a small clean container and place the tooth in it. Alternatively, the tooth can be held inside the cheek (between the cheek and gum), but only if the person is old enough and alert enough not to accidentally swallow it.
Saline solution (contact lens solution) — acceptable if nothing else is available.

Do not store the tooth in:

Tap water — the osmolality is wrong and it kills root cells quickly
Any disinfectant or antiseptic solution
A dry container, tissue, or your pocket

Step 6: Get to a Dentist Immediately

Time is everything. Ring my practice on your way so I can prepare for reimplantation the moment you walk through the door. If my practice is closed, go to the nearest available dentist or, failing that, your hospital A&E department.

The ideal window is within 30 minutes. Reimplantation can still be attempted up to about 60 minutes after the tooth was knocked out, but the success rate drops significantly with every passing minute. After an hour, reimplantation is still sometimes attempted, but the long-term prognosis is much less favourable.

The Reimplantation Procedure

When you arrive at my practice with a knocked-out tooth, here's what I'll do:

Assessment

I'll examine the tooth and the socket. I'll check whether the tooth is intact (no root fracture), assess the condition of the root surface, and examine the socket for bone fractures or damage to the surrounding tissue. An X-ray is usually taken to check for fractures that aren't visible to the eye.

Reimplantation

If the tooth and socket are suitable, I'll gently clean the socket to remove any blood clot that has formed, rinse the root surface with saline, and carefully reposition the tooth back into the socket. I use a gentle touch — the goal is to preserve as many of those vital root-surface cells as possible.

Splinting

Once the tooth is repositioned, I'll splint it to the neighbouring teeth using a flexible wire and composite resin. This stabilises the tooth while the periodontal ligament heals and reattaches to the bone. The splint is non-rigid — a small amount of natural movement is actually beneficial for healing.

The splint typically stays in place for two weeks for a straightforward avulsion. If there's damage to the bone around the socket, it may need to stay in for longer — usually four to six weeks.

Additional Treatment

Depending on the circumstances, I may also:

Prescribe antibiotics to prevent infection
Administer a tetanus booster if the wound was contaminated with soil (or refer you to your GP for this)
Begin root canal treatment — in most cases, the nerve inside a reimplanted tooth will not survive. Root canal treatment is typically started within one to two weeks of reimplantation and is essential for the long-term survival of the tooth

Follow-Up Care

Successful reimplantation requires careful follow-up. Here's what to expect:

The First Two Weeks

Eat soft foods and avoid biting on the reimplanted tooth.
Brush your other teeth normally, but be very gentle around the splinted area. Use a soft toothbrush and be careful not to disturb the splint.
Rinse with chlorhexidine mouthwash (I'll prescribe or recommend one) twice daily to keep the area clean while brushing is difficult.
Avoid contact sports and any activity that risks further trauma to the area.

Splint Removal

I'll remove the splint after two weeks (or longer if bone was fractured). This is a quick, painless appointment. I'll take another X-ray to check how the tooth and surrounding bone are healing.

Root Canal Treatment

As I mentioned, the nerve inside a reimplanted tooth almost always dies. I'll typically begin root canal treatment within seven to fourteen days of reimplantation. This involves removing the dead pulp tissue, cleaning the canals, and sealing them. Root canal treatment on a reimplanted tooth is carried out over several appointments, as I'll place a medicament inside the tooth between visits to ensure all infection is resolved before the final seal.

Ongoing Monitoring

I'll continue to monitor the reimplanted tooth with regular X-rays over the following months and years. I'll be checking for:

Successful healing of the periodontal ligament — the tooth should feel firm and stable
Root resorption — in some cases, the body gradually breaks down the root of the reimplanted tooth over time. This doesn't always cause symptoms, which is why regular X-rays are important
Ankylosis — the tooth fuses directly to the bone rather than reattaching via the periodontal ligament. This can cause problems later, particularly in growing children, as the ankylosed tooth doesn't move with the surrounding bone during jaw growth

What's the Prognosis?

The prognosis for a reimplanted tooth depends on several factors:

How quickly the tooth was reimplanted — teeth reimplanted within 30 minutes have the best outcomes
How the tooth was stored — teeth kept in milk or a preservation solution do significantly better than those that were allowed to dry out
Whether the root surface was damaged — teeth that were handled carefully by the crown have better periodontal healing
The stage of root development — in children and adolescents, teeth with open (still-developing) root tips have a better chance of the nerve surviving and the root continuing to develop

With ideal conditions — quick reimplantation, proper storage, gentle handling — survival rates of 85–97% have been reported at five years. Even when conditions aren't perfect, reimplantation is almost always worth attempting, as even a tooth that eventually fails buys time and preserves bone while you plan a longer-term replacement.

Baby Teeth vs. Permanent Teeth

An important distinction: baby teeth (primary teeth) that are knocked out should NOT be reimplanted. Attempting to reimplant a baby tooth risks damaging the developing permanent tooth underneath it. If your child knocks out a baby tooth, control any bleeding with gentle pressure, and contact me so I can check that no damage has been done to the permanent tooth bud. The permanent tooth will eventually come through naturally.

Permanent teeth — which begin coming through from about age six — should always be reimplanted if possible. Every permanent tooth is irreplaceable, and saving one is always worth the effort.

Prevention: Mouthguards and Awareness

Knocked-out teeth are most common during contact sports, and a mouthguard is by far the most effective way to prevent them. A custom-fitted mouthguard made by a dentist provides significantly better protection than an off-the-shelf boil-and-bite version. It fits precisely, stays in place during impact, and distributes force across all the teeth rather than concentrating it.

If you or your child plays rugby, GAA, hurling, hockey, boxing, martial arts, or any sport with a risk of facial impact, I strongly recommend a custom mouthguard. I can make one quickly and comfortably at my practice.

Beyond sport, be aware of environmental hazards — wet floors, uneven surfaces, loose rugs — particularly for children and older adults, who are most prone to falls.

Key Takeaways

If I could leave you with three things to remember, they'd be these:

Pick up the tooth by the crown, never the root.
Keep the tooth in milk if you can't put it back in the socket.
Get to a dentist within 30 minutes — ring ahead so I'm ready for you.

Those three steps, carried out calmly and quickly, give your tooth the best possible chance of survival. If you'd like me to make you a custom mouthguard, or if you have any questions about dental trauma, please get in touch with my practice in Carlow.

Knocked-Out Tooth: What to Do and How I Can Help