A knocked-out tooth, medically termed avulsion, is one of the most severe dental emergencies a person can experience. Immediate, correct action is the most important factor determining whether the tooth can be saved and successfully reattached. The long-term survival of the tooth depends entirely on the viability of the periodontal ligament (PDL) cells on the root surface. The chances of a favorable outcome drop significantly for every minute the tooth is out of its socket, making a rapid response crucial.
Immediate First Aid for Tooth Avulsion
The first moments after a tooth is knocked out are the most important. Confirm the avulsed tooth is permanent, as baby (primary) teeth should never be reinserted due to the risk of damaging the developing permanent tooth underneath. Once confirmed, locate the tooth and pick it up only by the crown, which is the white chewing surface, taking care to avoid touching the root.
If the tooth is visibly dirty, gently rinse it for no more than ten seconds under cold, running water or saline solution. Do not scrub the root surface, use soap, or wrap the tooth in dry tissue, as this destroys the fragile periodontal ligament cells. Preserving the viability of these cells is the primary goal, as they are responsible for reattachment.
The best immediate action is gentle reinsertion into the socket at the site of the injury. Carefully push the tooth back into its original position, using the adjacent teeth as a guide for orientation. Once seated, bite down gently on a clean cloth or gauze to hold the tooth in place while seeking immediate professional dental care. This rapid reinsertion maximizes success by preventing the PDL cells from drying out.
If the tooth cannot be immediately reinserted, controlling any bleeding from the socket is the next priority. Apply light pressure to the area with a clean piece of gauze or cloth. Contact a dentist or emergency dental service immediately while preparing the tooth for transport, as every minute counts toward the 30-to-60-minute window for the best prognosis.
Essential Preservation and Transport Methods
If immediate reinsertion is not possible, keeping the root surface moist in a suitable medium is necessary to maintain the vitality of the PDL cells during transport. The tooth should ideally be kept out of the mouth for less than 30 minutes, as the survival rate decreases rapidly after this point.
Hank’s Balanced Salt Solution (HBSS), often found in specialized preservation kits, is the gold standard for maintaining cell viability due to its balanced pH and osmolality. If HBSS is unavailable, cold whole milk is the most accessible and recommended alternative, compatible with PDL cells for up to two hours. Saline solution is also an acceptable option.
If no solutions are available, placing the tooth inside the mouth between the cheek and the gum is a temporary last resort, provided the person is conscious and can avoid swallowing it. This uses saliva to keep the tooth moist, though saliva is not an ideal storage medium. Never transport the tooth in plain tap water, as its hypotonic nature causes the PDL cells to swell and burst, making successful reattachment unlikely.
Urgent Dental Treatment and Prognosis
Upon arrival, professional treatment focuses on securing the tooth and promoting reattachment. The dentist will assess the tooth and socket, cleaning the area and irrigating the socket with saline to remove any clots. If the tooth was not reinserted, the dentist will perform the final re-implantation.
The tooth must be stabilized with a non-rigid, flexible splint bonded to the avulsed tooth and adjacent healthy teeth. This splint is typically kept in place for about two weeks to allow the periodontal ligament fibers time to heal and reattach. Systemic antibiotics and antiseptic mouth rinses, such as chlorhexidine, are often prescribed to prevent infection.
Most avulsed permanent teeth with a fully developed root (closed apex) require root canal treatment within seven to ten days after replantation. This is necessary because the trauma severs the blood vessels and nerves, leading to pulp death and necrosis, which can trigger inflammatory root resorption. For teeth with an immature root (open apex) replanted quickly, the root canal may be delayed to monitor for signs of revascularization.
The prognosis is heavily influenced by the time the tooth spent outside the socket and the storage method. A tooth replanted within five minutes has the highest chance of survival, with success rates decreasing significantly after 60 minutes. Primary complications monitored are inflammatory root resorption (where the body dissolves the root tissue) and replacement resorption, also known as ankylosis. Ankylosis occurs when the tooth fuses directly to the jawbone, requiring diligent follow-up care.