Knocked-out tooth

A tooth that comes right out of its socket after a blow or a fall is one of the few dental emergencies where the clock really matters. An adult tooth can be put back and will reattach, provided you act fast and handle the root correctly. A baby tooth is never put back. The distinction changes everything, so the first thing to work out on the spot is which kind of tooth you are holding.

The first few minutes decide the outcome

The best results belong to teeth put back into the socket at the scene, within the first fifteen to thirty minutes. The surface of the root carries living cells from the ligament that held the tooth in the bone, and they determine whether it knits back in. Those cells die as soon as they dry out, so an hour spent on a tissue or in a pocket almost always means the tooth will never attach properly. For an adult dealing with their own tooth, the order is as follows.

• Find the tooth and pick it up by the crown only — the white part normally visible in the mouth. Do not touch the root, do not scrub or scrape it, and do not wipe it with alcohol or antiseptic.
• If the tooth is dirty, rinse it for a few seconds in milk or saline. With nothing else to hand, a brief rinse of about ten seconds under cold running water is acceptable, but never soak the tooth in water: water destroys the root cells faster than air does.
• Put the tooth back into the socket the same way round as its neighbours. It should go in without force; press gently with a finger until it sits level with the other teeth.
• Bite on a clean gauze or handkerchief so that the tooth does not fall out again.
• Get to a dentist immediately — within the hour, not the next day.

Before replanting, glance into the socket: if a large fragment of bone is visible or the gum is torn into a flap, the tooth will not seat properly, and it is better not to waste time but to carry it to the dentist in a cup of milk.

If the tooth will not go back in

This happens often: the person is shocked, a child is bleeding, hands shake, the tooth will not seat. Nothing is lost yet — all that matters now is getting the tooth there wet.

• Milk is the best of what is usually available at home or in the shop next door. Ordinary cold milk of any fat content will do.
• Saline, if you happen to have some, for instance in a car first aid kit.
• The person's own saliva — spit into a clean jar or tub and drop the tooth in. An adult may hold the tooth inside the cheek, but a child must not: they may swallow or inhale it.
• What not to do: carry the tooth in water, in alcohol or in antiseptic, wrap it in a dry tissue, lay it straight on ice or put it in the freezer.

Even if several hours have passed and the tooth has dried out, take it with you all the same. Sometimes it can still be used, and if not, it tells the dentist whether the tooth came out whole or a piece of root is still in the bone.

With baby teeth the rule is reversed

A knocked-out baby tooth is never put back. The bud of the adult tooth lies in the jaw directly beneath it, and trying to replant the baby tooth can damage that bud badly enough for the adult tooth to come through mottled, crooked, or not at all. The harm is permanent and there is nothing to gain in return.

What to do instead: calm the child, press clean gauze into the socket for a few minutes to stop the bleeding, put something cold against the cheek, and see a dentist the same day. The gap is usually left alone, since the adult tooth will arrive in its own time. A denture comes up only occasionally, mainly when the missing tooth leaves an obvious gap at the front or the child's speech suffers because of it.

Age gives a clue as to which tooth it was: baby teeth are replaced roughly between six and twelve years. More reliable is the tooth itself — a baby tooth has a short, thin root that is often partly dissolved already, and a smaller, whiter crown. If in doubt, put it in milk and leave the decision to the dentist.

When the tooth is not the whole story

A blow hard enough to knock out a tooth rarely lands on the tooth alone. Before dealing with the tooth, look at the person as a whole, and call an ambulance (in Spain, Italy, Portugal, Poland and Ukraine on the single European number 112) if any of the following follows the injury:

• loss of consciousness, however brief, confusion, repeated vomiting, severe headache or a seizure;
• bleeding from the mouth that does not stop with ten minutes of pressure;
• the jaw will not close, the bite has changed, the mouth will not open, or the face is visibly lopsided;
• a bout of coughing, choking or wheezing straight after the injury — a fragment of tooth may have gone into the airway.

The missing tooth deserves a paragraph of its own. If it is neither in the mouth nor on the ground, keep looking: it may have been swallowed, inhaled, or driven into the soft tissues, most often into the thickness of the lip, where it later turns septic. Say so plainly to whoever examines the patient; if inhalation is suspected, a chest X-ray is taken. A swallowed tooth normally passes on its own and is harmless, an inhaled one needs a bronchoscopy.

One more qualification. If the tooth has not come out but is merely loose, pushed sideways or driven up into the gum, do not pull it out or reposition it yourself — that is the dentist's job. Lip and tongue wounds contaminated with soil are a reason to check when the last tetanus vaccination was given.

What the dentist will do

The dentist checks the position of the tooth and adjusts it if needed, or cleans and replants it if it arrives separately. The tooth is then held with a splint: a fine wire or a strip of composite joins it to the neighbouring teeth for a couple of weeks so that it cannot move while it reattaches. An X-ray shows whether the root and the socket wall are intact and whether a fragment has been left in the tissues.

After a week or two, teeth with a fully formed root have the dead pulp removed and the canal filled. This is a planned part of the treatment rather than a sign that something went wrong: without it the dead pulp becomes infected and the root dissolves quickly. In children and teenagers the root is often still open, and such a tooth can sometimes restore its own blood supply; the canal is then left alone and followed up with X-rays.

If the tooth is never found or cannot be saved, the gap is first covered with a removable denture and, once healing is complete, a bridge or an implant is discussed. A growing teenager is not given an implant: the jaw is still changing, and in time the implant would sit at the wrong level. The usual approach is to wait until growth finishes and use a temporary solution meanwhile.

How healing goes

For the first few days chew on the other side and eat soft food; brush as usual, but around the splint use a soft brush and a light hand. Chlorhexidine rinses are prescribed if the dentist thinks them worthwhile. Pain responds to ordinary over-the-counter painkillers; avoid smoking and drinking through a straw.

Reattachment is checked more than once: typically at a month, then at three months, six months and a year, and sometimes the tooth is followed for several years. Three things are looked for. Darkening of the crown means the pulp has died and the canal needs treating. Root resorption is the gradual dissolving of the root from inside or outside, which can cost the tooth later on. Ankylosis is fusion of the root straight to the bone with no ligament in between: in an adult it causes no trouble for years, but in a growing child that tooth stays where it is while the jaw grows around it and gradually ends up lower than its neighbours. All of these are easier to deal with the sooner they are spotted, so review appointments are worth keeping even when nothing hurts.

Protecting teeth in advance

Most knocked-out teeth are lost in sport, in fights and in falls from bicycles and scooters. Simple measures work: a mouthguard for any contact activity and for combat sports, a helmet with face protection where one is made for the sport, and a seat belt and child seat in the car. A mouthguard made to measure by a dentist from an impression protects better than a shop-bought one and does not get in the way of breathing. At home it is worth padding sharp furniture corners while a child is learning to walk. And one everyday habit that costs more teeth than people expect: never open bottles, packaging or hair clips with your teeth.

Online consultation

An online appointment earns its keep in those first confused minutes: from a description and a photograph the doctor helps tell a baby tooth from an adult one, advises whether to replant it right now, what to transport it in and where to go in your town, and judges whether there are signs of a head injury that need an ambulance first. Later on it is useful for going through the dentist's report and the X-ray, understanding what the splint and the root canal treatment are for, what a crown that darkens a few months on means, and when an implant can be considered for a teenager.

This material is for information only and does not replace medical advice.