A knocked-out permanent tooth is one of the few dental emergencies where the clock is running in real time. If you get to a dentist within 30 minutes with the tooth kept correctly, re-implantation has a good success rate. After an hour, that window closes sharply. After two hours, re-implantation is rarely viable.
This article is for permanent (adult) teeth only. Baby teeth are not re-implanted — if a child knocks out a baby tooth, see a dentist to check that no root fragment remains, but do not attempt to put it back.
The first two minutes
Pick up the tooth by the crown — the white part you can see in the mouth. Do not touch the root. The root surface is covered in periodontal ligament cells that must survive for re-implantation to work; handling the root crushes and contaminates them.
If the tooth is dirty, rinse it gently under cold running water for ten seconds. Do not scrub it. Do not use soap, alcohol, or hydrogen peroxide. Do not dry it or wrap it in tissue.
"The single most damaging thing people do is wrap the tooth in tissue. It desiccates the ligament cells within minutes. Keep the tooth wet."
— Dr. Kwame Mensah, BDS, MDS
Where to store the tooth
The best storage medium, in order of preference:
- Back in the socket. If the patient is conscious, alert, and not at risk of swallowing it, gently push the tooth back into the socket in the correct orientation and hold it in place with light biting pressure on a cloth.
- Under the tongue or between the cheek and gum. Saliva keeps the ligament cells alive. This works for adults and older children; do not use this method for young children who might swallow the tooth.
- Milk. If the tooth cannot be replaced in the socket, milk is the best widely available storage medium. Its osmolarity and protein content maintain cell viability for up to an hour. Whole or semi-skimmed both work.
- Saline (salt water). A pinch of salt in a glass of water is a reasonable fallback if milk is unavailable.
- Water. A last resort only. Plain water causes osmotic stress on the ligament cells, which damages them within 30 minutes. It is better than nothing for a short journey.
Get to a dentist immediately
Call your clinic or any emergency dental service as you are leaving. Tell them a tooth has been avulsed and you are on your way. A good clinic will clear a chair for you.
If you cannot find a dentist within 20 minutes, go to the nearest hospital emergency department. Some hospitals — particularly those with ENT or maxillofacial departments — can perform emergency re-implantation.
What the dentist will do
The dentist will clean the socket, check for bone fracture, and gently re-implant the tooth. A soft splint (a flexible wire bonded to adjacent teeth) will hold the tooth in place for 2–4 weeks while the ligament reattaches. You will likely receive antibiotics.
A root canal is almost always needed later — the nerve tissue inside the tooth rarely survives avulsion — but this is a routine procedure and does not affect the long-term survival of the tooth itself.
Success is not guaranteed. Even a perfectly handled and quickly re-implanted tooth can eventually be lost to resorption or ankylosis. But giving the tooth the best chance costs nothing.