If an adult tooth is knocked clean out of the mouth, the single most useful thing most people can do, after trying to put it back in, is to keep it in milk and get to a dentist fast. How a knocked-out tooth is stored in the first 30 to 60 minutes often decides whether it can be replanted and survive, or whether it is lost for good. The reason is a thin layer of living cells on the root surface, the periodontal ligament, which dries out and dies quickly in the wrong environment.
This guide explains the storage options in plain order of preference, why water is a poor choice, and the time limits that matter. It is a companion to our full knocked-out tooth first aid guide, which covers the complete step by step.
Key takeaways
- The best place for a knocked-out adult tooth is back in its socket straight away, if that can be done safely.
- If it cannot be replanted, keep it moist. Cold milk is the best widely available storage liquid.
- Saliva, by holding it inside the cheek or in a cup of the person's own spit, is the next option.
- Avoid water. Plain water damages the root cells faster than milk or saliva.
- Time matters. Aim to replant or reach a dentist within 30 to 60 minutes. After about an hour of dry storage, the outlook drops sharply.
- Never scrub the root or let the tooth dry out. Hold it by the crown, not the root.
- Baby teeth are not replanted, so this applies to adult teeth only.
The one rule: keep the root cells alive
Every storage decision comes back to one principle. You are trying to keep the living cells on the root surface alive until a dentist can replant the tooth. Those cells survive best in a liquid with the right balance of salts and acidity, close to the body's own fluids. Liquids that are too plain, too acidic or too sugary, and dry air, all kill them faster. That is why milk works and water does not, and why time is the most important factor of all.
Storage media, ranked
If you cannot put the tooth back in its socket, use the best option you can reach quickly. The International Association of Dental Traumatology lists milk and balanced salt solution as the preferred media, with saliva and saline acceptable when nothing better is at hand.
| Option | How good it is | Where to find it |
|---|---|---|
| Back in the socket | Best of all. Cells stay where they belong | Replant gently straight away, then bite on a clean cloth |
| Cold milk | Excellent. Salts and acidity close to body fluids keep cells alive for hours | Fridge, shop, cafe, most homes |
| Balanced salt solution (such as Hank's) | Excellent, the laboratory standard, but rarely on hand | Some first aid and sports kits |
| Saliva | Good for short periods. Hold inside the cheek, or spit into a cup and submerge the tooth | Always available |
| Saline (contact lens or wound saline) | Acceptable for a short time | First aid kit, pharmacy |
| Water | Poor. Bursts and kills root cells. Use only if there is truly nothing else | Anywhere, but it is the last resort |
Why not water
Plain water seems like the obvious choice, but it is one of the worst. Water has none of the salts that the root cells need, so it pulls fluid into the cells until they swell and burst. Within minutes the cells that allow the tooth to reattach are badly damaged. Milk, saliva and saline all sit much closer to the body's own salt balance, which is why they preserve the cells far longer.
Time limits that matter
The clock is the most important factor. A tooth replanted within about 15 minutes has the best chance. Stored correctly in milk or saliva, a tooth can often still be replanted with a reasonable outlook up to around an hour, and sometimes longer. Once a tooth has been dry for about 60 minutes, most of the root cells have died, and while the tooth can sometimes still be placed back, it is more likely to fuse to the bone and be slowly lost over years. This is why the message is always the same. Replant if you can, store in milk if you cannot, and get to a dentist immediately.
What the dentist does next
At the clinic, the tooth is replanted if it has not been already, then held in place with a small flexible splint for a week or two while the area heals. Most replanted adult teeth later need root canal treatment, because the nerve does not usually survive being knocked out. The tooth is then monitored over months and years. Even when a replanted tooth is eventually lost, getting it back in early preserves the bone and keeps options like a dental implant simpler down the track.
Frequently asked questions
Should I rinse a dirty knocked-out tooth before storing it?
Only briefly, and gently. If the tooth is visibly dirty, rinse it for a few seconds in milk or saline, or in cold running water if nothing else, holding it by the crown. Do not scrub it, do not use soap, and do not wipe the root.
Can I put the tooth in a tissue or my pocket?
No. Dry storage is the worst option because the root cells die quickly. The tooth must stay moist in milk, saliva or saline at all times.
What kind of milk is best?
Plain cow's milk, ideally cold, works well, whether full fat or reduced fat. Flavoured or sweetened milks are not ideal but are still far better than water. Plant-based milks have not been shown to work the same way, so use dairy milk if you can.
My child knocked out a baby tooth. Should I store it?
Baby teeth are not replanted, because doing so can damage the developing adult tooth underneath. Keep your child calm, control any bleeding with gentle pressure, and see a dentist to check the area, but there is no need to preserve the tooth itself.
A knocked-out tooth is a true dental emergency, and the right storage in the first hour can be the difference between saving and losing it. If this happens, replant if you can, store in milk if you cannot, and contact the team at Lumi Dental in Melrose Park straight away. See our full first aid guide, our advice on a suspected broken jaw or facial injury, and our overview of cracked tooth problems. Current new patient information is on our offers page.
This article is general information and is not a substitute for urgent dental or medical care. If a tooth is knocked out, seek dental help immediately.
