Knocked-Out Tooth: Emergency Steps That Could Save It

A tooth getting knocked out is one of the most time-critical dental emergencies you can face. Whether it happens during sport, a fall, or an accident, what you do in the first 30 to 60 minutes can determine whether the tooth survives or is lost permanently.

This guide walks you through exactly what to do, step by step. Known medically as tooth avulsion, this is a situation where acting fast really matters.

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Why Time Matters So Much

The root surface of a tooth is covered in specialised cells called periodontal ligament (PDL) cells. These cells are what allow the tooth to reattach to the bone and gum when it's replanted. PDL cells begin to die within minutes of being exposed to air, and they are damaged by drying out, contact with chemicals, or being handled roughly.

Research shows that teeth replanted within 30 minutes have the highest success rates — often above 90%. Between 30 and 60 minutes, success rates begin to decline. After 60 minutes out of the socket, the prognosis becomes significantly worse, though reimplantation may still be attempted.

This is why proper storage is so important. Milk is the most readily available medium that closely matches the conditions the root cells need to survive. It has the right pH and osmolality to keep cells alive for up to several hours.

What Your Dentist Will Do

When you arrive at the dental practice or emergency clinic, the dentist will assess the tooth and the socket. The typical treatment process involves:

• Replanting the tooth: If you haven't already done so, the dentist will gently clean the tooth and socket, then place the tooth back into position under local anaesthetic.
• Splinting: A flexible splint (a thin wire bonded to the teeth) is placed to hold the replanted tooth in position while it heals. This typically stays in place for one to two weeks.
• X-rays: To check the position of the tooth and assess any damage to the surrounding bone.
• Root canal treatment: In most cases, the nerve inside the tooth will not survive the trauma. Root canal treatment is usually started within one to two weeks of replantation to prevent infection and inflammation inside the tooth.
• Follow-up appointments: Regular monitoring over the following weeks and months to check healing and watch for complications such as root resorption (where the body gradually dissolves the root).

Baby Teeth vs Adult Teeth

It's important to know that the advice above applies only to adult (permanent) teeth. If a child's baby (primary) tooth is knocked out, do not try to replant it. Pushing a baby tooth back into the socket can damage the developing adult tooth underneath.

If a child has a baby tooth knocked out, control any bleeding by having them bite on a clean cloth, apply a cold compress to the lip or face if swollen, and see a dentist to check for any other damage. The gap will eventually be filled by the adult tooth when it comes through naturally.

For older children and teenagers with adult teeth, follow the same emergency steps as for adults. If you're unsure whether the tooth is a baby tooth or an adult tooth, store it in milk and let the dentist decide.

Long-Term Outlook

The long-term success of a replanted tooth depends on several factors, including how quickly it was replanted, how it was stored, and the extent of damage to the root and surrounding tissues. With prompt treatment:

• Many replanted teeth can last for years or even decades with proper care
• Root canal treatment is usually needed to prevent internal infection
• Some replanted teeth may eventually develop root resorption, where the body gradually breaks down the root over time. This can happen months or even years later
• If a replanted tooth is eventually lost, replacement options include bridges, dentures, or dental implants

Prevention: Mouthguards Save Teeth

If you or your children play contact sports or activities with a risk of falls, wearing a properly fitted mouthguard is one of the best ways to prevent dental injuries. Custom-made mouthguards from your dentist offer the best protection and comfort, though boil-and-bite options from sports shops provide a reasonable alternative.

Sports where mouthguards are particularly recommended include rugby, hockey, boxing, martial arts, cricket, football, and mountain biking. Even sports like basketball and skateboarding carry a significant risk of dental trauma.

Where to Get Emergency Help

A knocked-out adult tooth is a true dental emergency. Here is where to go.

• Your own dentist: Call immediately. Most practices prioritise genuine emergencies and may have an out-of-hours number on their answerphone.
• NHS 111: If your dentist is unavailable, call 111 for directions to the nearest emergency dental clinic.
• A&E: If the injury involves facial trauma, heavy bleeding, broken bones, or a head injury, go to A&E. They can stabilise the situation, though dental specialists may be needed for the final treatment.

Tooth Storage Options Compared

How you store a knocked-out tooth directly affects whether it can be saved. Here is a quick reference.

Frequently Asked Questions

Can a knocked out tooth be put back in?

Yes. In many cases a knocked-out adult tooth can be successfully re-implanted if you act quickly. The best outcomes occur when the tooth is replanted within 30 minutes. Pick it up by the crown, rinse gently if dirty, and try to push it back into the socket. If you cannot do this, store it in milk and get to a dentist immediately.

How long can a knocked out tooth survive outside the mouth?

The critical window is 30 to 60 minutes. Teeth replanted within 30 minutes have success rates above 90%. After 60 minutes, the chances drop significantly. Storing the tooth in milk can extend viability for up to several hours, but getting to a dentist as quickly as possible is always the priority.

What do I store a knocked out tooth in?

Cold milk is the best readily available option. It has the right pH and osmolality to keep root cells alive. Other options include saline solution, the person's own saliva (inside the cheek), or a tooth preservation kit. Never store the tooth in water or wrap it in tissue.

Should I put a knocked out baby tooth back in?

No. If a child's baby tooth is knocked out, do not try to replant it. Pushing a baby tooth back in can damage the developing adult tooth underneath. Control bleeding, apply a cold compress, and see a dentist.

Does a reimplanted tooth need root canal treatment?

In most cases, yes. The nerve inside a knocked-out tooth usually does not survive the trauma. Root canal treatment is typically started within one to two weeks of replantation to prevent infection.

What happens if the tooth cannot be saved?

If the tooth is lost, replacement options include dental implants, bridges, or dentures. Dental implants are generally considered the best long-term solution. Your dentist can discuss timing and options once the area has healed.

How can I prevent knocked out teeth?

Wearing a properly fitted mouthguard during contact sports is the best prevention. Custom-made mouthguards from your dentist offer the best protection. Sports where mouthguards are recommended include rugby, hockey, boxing, martial arts, cricket, and football.

Where should I go if I knock out a tooth?

Call your own dentist first. If unavailable, call NHS 111 for emergency dental clinic directions. If the injury involves facial trauma, heavy bleeding, or a head injury, go to A&E. You can also search for emergency dental appointments near you.