Why the first few minutes matter most
When an impact knocks a whole tooth out of its socket — what dentistry calls dental avulsion— the root remains covered by a thin tissue called the periodontal ligament, which is what allows the tooth to reattach to the bone if it is reimplanted in time. This tissue is extremely fragile and starts to die as soon as the tooth dries out outside the mouth.
That's why the outlook depends, above all, on two factors that are decided in the first few minutes: how long the tooth spends out of place, and what medium it is kept in on the way to the clinic. Once that window has passed, even if the tooth can be put back, the chances of the body accepting it stably drop markedly.
This only applies to permanent teeth. A baby tooth knocked out by an impact is never reimplanted: trying to do so can damage the permanent tooth forming underneath, so in young children the tooth is not put back, although the rest of the steps — conserving it and going to the clinic — are just as important for assessing the impact.
What to do: hold the tooth by the crown, not the root
The first thing is to find the tooth and always hold it by the crown — the white part that is normally visible when smiling — avoiding touching the root at all times. The root holds the tissue that makes it possible for the tooth to reattach, and handling it, rubbing it or scraping it to "clean it" damages exactly what needs to be preserved.
If the tooth is dirty with soil or blood, a brief rinse under a gentle stream of water or with saline solution is enough, always holding it by the crown, without rubbing or using soap, alcohol or any other product.
If the person is calm and it's possible, you can try to put the tooth back into its socket with gentle pressure, without forcing it, and carefully bite down on a piece of gauze or a clean handkerchief to hold it in place on the way to the clinic. If this doesn't work or it hurts too much, don't keep trying: move straight on to the next step.
- Hold the tooth by the crown, never by the root.
- If it's dirty, rinse it with water or saline solution without rubbing.
- Try to reinsert it into its socket if possible, without forcing it.
- If it cannot be reinserted, keep it in milk or saline solution.
- Go to an emergency dental clinic immediately.
How to transport it to the clinic
When the tooth cannot be put back in straight away, the most important rule is never transport it dry. The storage medium is what most affects whether the root's ligament is still alive when the tooth reaches the surgery. From best to worst option:
- Inside the mouth itself, between the cheek and the gum (never swallowing it or holding it between the teeth), if the person is conscious and is not a young child at risk of swallowing it.
- Cold milk, which is the most accessible option and one of the best at preserving the root's tissue during the journey.
- Saline solution, if available, in a clean container where the tooth is completely covered.
- Never in tap water or wrapped in a dry cloth: running water damages the root's cells, and transporting it dry drastically reduces the chances of reimplantation.
If there is no milk or saline to hand, your own saliva inside the mouth is still a better preservative than air or tap water.
Why you must go urgently, not the next day
Every minute that passes reduces the chances of a successful reimplantation, so this is one of the few dental situations where "waiting to see how it develops" is not a reasonable option. The right thing to do is to go straight to an emergency dental clinic, or to an emergency department if it's outside opening hours, taking the tooth with you properly preserved.
At the clinic, the dentist will clean the area, assess the socket and the tooth itself, and, if conditions allow, go on to reimplant it and splint it in place for a period of time, as well as checking whether further nerve treatment is needed later on. Even when more time than ideal has passed, it's still worth having a professional assess the case: sometimes the tooth can still be saved, and if not, other injuries linked to the impact need to be ruled out (fractures to other teeth, wounds to the gum or lip, or damage to the bone).
- A whole tooth has been knocked out by a blow, an accident or a fall
- The tooth has moved, shifted, or looks "longer" than normal after the impact
- There is bleeding in the gum or lip that does not stop with pressure
- The impact has affected several teeth or a young child
Whenever there is an impact with a knocked-out tooth, the priority is to go urgently with the tooth properly preserved, not to wait and see if "it sorts itself out".