Dental Emergencies: What to Do If You Knock Out or Injure a Tooth

What to Do When a Tooth Is Knocked Out or Injured

A tooth that has been knocked out, displaced, or fractured represents one of the situations in dentistry where the actions taken in the first hour have the largest effect on the long-term outcome. The difference between a tooth that can be reimplanted successfully and one that cannot is often a matter of how the tooth was handled, what it was stored in, and how quickly the patient was seen. This article describes the steps that improve the prognosis for an injured tooth, the differences between the major types of dental trauma, and what to expect when seeking care for a dental injury.

When a Permanent Tooth Has Been Knocked Out

A permanent tooth that has been completely knocked out of the socket, called an avulsed tooth, has the best chance of being saved when it is reimplanted within the first hour after the injury. The reason for this narrow window is biological. The root surface of a tooth is covered by living cells of the periodontal ligament, which connect the tooth to the surrounding bone. When the tooth is out of the socket and exposed to air, these cells begin to die. If the tooth is reimplanted while the cells are still viable, healing can occur in a way that allows the tooth to remain in function for many years. If the cells have died, the body treats the reimplanted tooth as a foreign object, and the long-term outcome is generally less favorable.

The steps that preserve the viability of these cells are straightforward. The tooth should be picked up by the crown, the white visible part, and not by the root. Touching the root surface can damage the cells that need to remain intact for successful reimplantation. If the tooth is visibly contaminated with dirt or debris, it can be briefly rinsed under cold running water for a few seconds or, if available, rinsed in saline or milk. The tooth should not be scrubbed, dried, or wrapped in tissue, since each of these damages the root surface.

If the patient or a person assisting them feels able to do so, the tooth can be gently reinserted into the socket immediately. The patient then bites down on a clean cloth or gauze to hold the tooth in place during transport. Reimplantation by the patient or a bystander, when done within the first few minutes, produces the best results because the cells on the root surface have the least time to be exposed.

If immediate reimplantation is not feasible, the tooth must be kept moist during transport. The best storage media are, in order of preference, a commercially available tooth preservation solution if one is available, cold milk, saline, or the patient's own saliva either inside the mouth in the cheek pouch or in a container collected from the mouth. Water is not a suitable storage medium because it causes the cells on the root surface to swell and die.

The patient should then be seen by a dentist or endodontist as quickly as possible. Within the first hour is the target. Outside this window, reimplantation can still be attempted, but the prognosis declines progressively with each additional period the tooth is out of the socket.

When a Baby Tooth Has Been Knocked Out

A baby tooth, also called a primary tooth, that has been knocked out is not reimplanted. The reason is that the developing permanent tooth is sitting directly above the socket of the primary tooth, and attempting to reinsert the primary tooth can damage the permanent tooth before it has erupted. The patient should still be seen promptly to confirm that no other injuries are present and to plan for the management of the empty space, which depends on the age of the child and the position of the tooth, but the primary tooth itself is generally not retained.

This is one of the more counterintuitive aspects of pediatric dental trauma. Parents whose instinct is to recover and try to reinsert a knocked-out baby tooth are best served by knowing in advance not to do this and by bringing the tooth to the dental visit only for confirmation that it was complete.

When a Tooth Has Been Displaced but Not Knocked Out

A tooth that has been pushed out of its normal position but remains in the socket, called a luxated tooth, requires prompt evaluation rather than at-home repositioning. The injury affects the supporting ligament and surrounding bone, and the tooth often needs to be repositioned by a clinician and stabilized with a flexible splint during the healing period. Attempting to push the tooth back into place at home can cause additional damage and is not recommended.

The patient should keep the area as undisturbed as possible during transport to the dental office and should avoid biting on the affected tooth. If significant bleeding is present, gentle pressure with a clean cloth can be applied to the area.

When a Tooth Has Been Fractured

A tooth that has been chipped, cracked, or fractured requires evaluation, although the urgency depends on the extent of the fracture and on whether the pulp is involved. A small chip in the enamel can generally be addressed at a scheduled appointment within a few days. A fracture that extends into the dentin, the layer beneath the enamel, requires more prompt attention, often within the same day, since exposed dentin is sensitive and the underlying pulp is vulnerable to bacterial contamination through the exposed dentinal tubules.

A fracture that has reached the pulp, recognizable by a small bleeding spot in the center of the broken tooth, requires same-day evaluation. The pulp exposure allows bacteria to reach the inside of the tooth quickly, and prompt treatment is needed to preserve the long-term prognosis. Depending on the size of the exposure, the maturity of the tooth, and the time since the injury, treatment may involve protecting the exposed pulp with a biocompatible material, partial removal of the affected pulp tissue, or, in some cases, root canal therapy.

A fragment of a fractured tooth that has been recovered can in some cases be bonded back to the tooth as the restoration, which is one reason to bring any recovered fragments to the dental visit even when they appear too small to be useful.

What to Do While Arranging to Be Seen

For any dental trauma, a few measured steps can be taken while arrangements are made to be seen. A cold compress applied to the outside of the face for fifteen to twenty minutes at a time reduces swelling and provides some pain relief. Over-the-counter ibuprofen, taken according to the dosing instructions and assuming no medical contraindication, addresses both pain and inflammation. Eating should generally be avoided until the patient has been seen, both because chewing can disturb the injured area and because the patient may need anesthesia at the appointment.

Aspirin should not be placed directly on the gum or against the tooth, since it causes chemical burns to the oral tissues without providing meaningful local pain relief. The tongue should not be used to probe the injured area, since this can dislodge a tooth that is still partially supported.

Why Time Matters Beyond the First Hour

For an avulsed tooth, the first hour is the critical window for reimplantation. For other dental injuries, the timing is less narrow but still affects the outcome in important ways.

A displaced tooth that is repositioned and stabilized within a few hours generally has a better prognosis than one that is left in its displaced position overnight. A fractured tooth with a small pulp exposure has a substantially better prognosis when the exposure is treated within a few hours than when it is left untreated for a day or more. A tooth with damage that has not yet been evaluated may have findings that are not apparent without examination and imaging, including injuries to the root that affect the long-term plan.

This is one of the reasons specialist endodontic offices generally reserve time for urgent trauma cases each day. Dental trauma is one of the situations where the value of a same-day visit is most clearly supported by the long-term outcome.

Long-Term Follow-Up After Dental Trauma

Recovery from a significant dental injury is not complete at the end of the first visit. Teeth that have been injured can develop complications well after the initial healing appears to be successful, including pulp necrosis that develops months later, internal or external resorption of the root, and changes in the supporting bone. For these reasons, follow-up visits and radiographs are scheduled at intervals over the following months and years, even when the tooth appears to have healed normally at the early visits.

Patients and parents are best served by understanding in advance that this longer-term follow-up is part of the treatment plan and that the initial successful reimplantation or stabilization of a tooth does not mean that no further attention is needed. Identifying a developing complication early allows additional treatment to be planned at a point where the prognosis remains favorable.

Reducing the Risk of Future Dental Trauma

Several measures reduce the likelihood of dental trauma occurring or limit its severity when it does occur. An athletic mouthguard substantially reduces the risk of injury during contact sports and many recreational activities, and is one of the most straightforward preventive measures available. Custom-fitted mouthguards provided through a dental office are more effective than over-the-counter alternatives. A nightguard is appropriate for patients who grind or clench their teeth, since chronic grinding can produce cracks that eventually progress to fractures. Avoiding the habit of using teeth to open packages, hold objects, or bite into hard items reduces the risk of fractures that develop from non-traumatic causes.

These measures do not eliminate the possibility of dental trauma, since accidents occur regardless of how careful a patient is, but they substantially reduce the frequency with which preventable injuries occur.

About Tri-City Endodontics

Dr. Malhan and the Tri-City Endodontics team have practiced in Pasco for more than 25 years and accept urgent referrals for dental trauma from general dentists, pediatric dentists, and emergency facilities throughout the Tri-Cities region. Same-day appointments are reserved each day for these situations. Long-term follow-up is part of the treatment plan for any significant traumatic injury, since the response of the pulp and supporting tissues can change over time. Patients and parents are informed at each visit about the condition of the tooth, the findings on follow-up imaging, and the realistic prognosis, so decisions about additional treatment are made with a clear understanding of how the injured tooth is healing