If an adult (permanent) tooth is knocked out, the aim is to get it back in its socket as quickly as possible, ideally within 30 minutes, and to see a dentist straight away. Hold the tooth by the crown, never the root, keep it moist, and do not let it dry out. A baby tooth, by contrast, should not be put back in.
A knocked-out tooth (dentists call it an avulsed tooth) is one of the few true dental emergencies where minutes make a real difference. Knowing what to do before it happens helps you stay calm if it does.
First, check the person is okay
Before worrying about the tooth, check for more serious injuries. Call 000 or go to a hospital emergency department if there has been a blow to the head with loss of consciousness, confusion, vomiting or a severe headache, if there is heavy bleeding that will not stop with pressure, if the jaw may be broken, or if there is any difficulty breathing or swallowing.
Also make sure the tooth has not been inhaled or swallowed. If a tooth cannot be found and the person is coughing or wheezing, seek medical help.
Is it a baby tooth or an adult tooth?
This is the most important question, because the advice is different.
Baby teeth: do not replant
Do not try to put a knocked-out baby tooth back in. Replanting a baby tooth can damage the developing adult tooth sitting underneath it in the jaw. Instead, have the child bite gently on a clean cloth or gauze to control bleeding, keep the tooth to show the dentist if you have it, and arrange a dental visit soon so the area and nearby teeth can be checked.
If you are unsure whether it is a baby or adult tooth, do not replant it; store it in milk and get to a dentist quickly. As a rough guide, the front adult teeth usually come through between about six and eight years of age.
Adult teeth: act quickly
For an adult tooth, the cells on the root surface begin to die once they dry out, and that affects whether the tooth can successfully reattach. The quicker the tooth goes back in or into a suitable storage liquid, the better its chances.
Step by step: what to do with a knocked-out adult tooth
- Find the tooth and pick it up by the crown (the white part you normally see in the mouth). Do not touch the root.
- If it is dirty, rinse it briefly for a few seconds in milk or saline. If neither is available, a very quick rinse under cold running water is acceptable. Do not scrub it, use soap or wipe it with a cloth, and do not remove any tissue attached to the root.
- Try to put it back in the socket, facing the right way, if the person is conscious and cooperative. Push it gently into place with your fingers, then have them bite gently on a clean handkerchief or gauze to hold it there.
- If you cannot replant it, keep it moist. Place it in a small container of milk, saline, or the person’s own saliva. An adult can hold the tooth inside their cheek, but do not do this with young children, who may swallow it.
- Do not store the tooth in plain water or wrap it in a dry tissue. Water damages the root cells and drying out is the biggest threat to the tooth.
- Get to a dentist immediately, taking the tooth with you.
What happens at the dentist
When you arrive, your dentist will check the tooth, the socket, the surrounding teeth and the soft tissues, and take X-rays to look for fractures of the tooth root or the bone.
Replanting and splinting
If the tooth has not already been replanted, your dentist will clean the area and reposition it. If you replanted it yourself, they will check that it is in the correct position. The tooth is then held in place with a flexible splint, usually a thin wire or fibre bonded to the neighbouring teeth, typically for around two weeks. Your dentist may recommend a soft diet, careful cleaning and an antiseptic mouth rinse during this time, and they may also suggest you check with your doctor whether your tetanus protection is up to date.
Root canal treatment
When an adult tooth with a fully formed root is knocked out, the nerve inside it usually does not survive. Root canal treatment is commonly started within a week or two of replanting to reduce the risk of infection and of the root being gradually resorbed. In younger patients whose roots are still developing, there is some chance of the blood supply recovering, so your dentist may monitor closely instead.
Follow-up over months and years
Replanted teeth need regular reviews and X-rays, often over several years. Even with prompt treatment, outcomes vary. Some replanted teeth last for many years; others are slowly replaced by bone (a process called resorption) and are eventually lost. How long the tooth was out of the mouth and how it was stored are the biggest factors.
If the tooth cannot be saved
If a tooth cannot be replanted or is eventually lost, there are several ways to replace it, including a removable denture, a bridge or a dental implant. Each has advantages, limitations and costs, and suitability depends on your age, the health of the neighbouring teeth and the bone in the area.
Implants are generally not placed until the jaw has finished growing, so teenagers may need a temporary option for several years. For adults, our dental implants page explains how implants work. An implant with a CEREC crown starts from $5,500 per tooth, with a quote given after assessment; bone grafting or other procedures are extra. Like any surgery, implant treatment carries risks, including infection and the possibility that the implant does not integrate with the bone.
Preventing knocked-out teeth
Many dental injuries happen during sport, play and falls. A well-fitted mouthguard is strongly recommended for contact sports and any activity with a risk of a blow to the face, including rugby, AFL, soccer, hockey, basketball, martial arts and skateboarding. Custom-fitted mouthguards made by a dentist tend to fit more closely and comfortably than off-the-shelf options, which makes people more likely to wear them.
Children with protruding front teeth are more prone to dental injuries, which is one of the reasons an orthodontic assessment can be worthwhile.
When to see a dentist
A knocked-out adult tooth needs to be seen immediately. Also see a dentist promptly if a tooth has been pushed out of position, pushed up into the gum, loosened or broken, even if it does not hurt much. Injuries that look minor can still damage the nerve.
At our Macquarie Park practice we offer same-day emergency appointments where available. We are open Monday, Tuesday, Thursday and Friday from 9:00am to 6:00pm and Saturday from 8:30am to 4:00pm, and closed on Wednesday and Sunday. For a non-urgent dental problem, calling before 10am gives you a better chance of a same-day visit. Because a knocked-out tooth cannot wait, if we are closed or cannot see you straight away, go to another dentist or the nearest hospital emergency department.
Frequently asked questions
How long can a knocked-out tooth survive outside the mouth?
The sooner it is replanted the better, ideally within 30 minutes. Chances drop significantly after about an hour out of the mouth, especially if the tooth has dried out. Keeping it moist in milk, saline or saliva helps protect the root cells.
Should I put a knocked-out baby tooth back in?
No. Replanting a baby tooth can damage the adult tooth developing underneath. Control the bleeding, keep the tooth if you have it, and see a dentist so the area can be checked.
Can I store a knocked-out tooth in water?
Plain water is not recommended because it damages the cells on the root. Milk, saline or the person’s saliva are better short-term options; avoid letting the tooth dry out.
Will a replanted tooth last?
Some replanted teeth last many years, but outcomes vary. Most adult teeth need root canal treatment afterwards, and regular reviews are needed to watch for problems such as root resorption.
Do I need a tetanus shot after a knocked-out tooth?
If the tooth or wound was contaminated with soil or dirt, your dentist may suggest checking with your doctor that your tetanus vaccination is up to date.
If you or your child has a dental injury, get help quickly. Call North Ryde Dentistry on (02) 8090 1102 or book an appointment.
This article is general information only and is not a substitute for advice from your own dentist. Any treatment carries risks; your dentist will discuss whether it is suitable for you.