A knocked-out tooth (dental avulsion) is a medical emergency requiring immediate first aid to maximize the chances of saving the tooth. The swiftness of action and proper preservation before reaching a dentist are the most important factors for a positive outcome. This information focuses on handling this traumatic injury, especially when milk is the most readily available storage medium.
Why Preservation is Essential for an Avulsed Tooth
The prognosis of a re-implanted tooth depends almost entirely on the health of the Periodontal Ligament (PDL) cells, which are delicate fibers attached to the tooth’s root surface. These cells are responsible for reattaching the tooth to the jawbone. If the tooth dries out, these PDL cells die (become necrotic) within minutes, making successful re-implantation highly unlikely.
The tooth must be kept moist in a specific medium to maintain cell viability. Standard tap water is detrimental because its low osmolality (concentration of solutes) causes the PDL cells to swell and burst (cell lysis). A specialized storage medium is required to provide a balanced pH and osmolality, similar to the body’s natural state, protecting the integrity of these living cells.
The Optimal Preservation Time Limits in Milk
Milk is a recommended and accessible medium for short-term storage because its osmolality and pH are relatively compatible with PDL cell survival. It also contains nutrients that help sustain the cells. If the tooth cannot be reinserted immediately, it should be placed into milk right away for the best chance of successful re-implantation.
Immediate re-implantation within five minutes offers the best prognosis. Milk provides a viable window to transport the tooth, keeping PDL cells viable for up to six hours, though effectiveness diminishes significantly after two hours. Commercial solutions, such as Hank’s Balanced Salt Solution (HBSS), are superior for longer storage but are rarely available outside a clinical setting.
Proper Handling and Transportation of the Tooth
The most important rule when handling an avulsed tooth is to touch it only by the crown (the white chewing surface). Avoid touching, scrubbing, or wiping the root surface, as this damages the fragile PDL cells. If the tooth is visibly dirty, gently rinse it for no more than ten seconds with milk or sterile saline; never scrub it or use soap.
If immediate re-implantation is not possible, the tooth should be placed into the storage medium. The preferred medium is cold milk, as it is usually readily available. Another temporary storage option, provided the patient is conscious and cooperative, is to keep the tooth inside the mouth, between the cheek and gums. This method uses the patient’s saliva to keep the tooth moist, though saliva is not an ideal medium due to its lower osmolality and bacterial content.
What to Expect During Dental Treatment
Upon arrival, the dentist assesses the tooth’s condition and PDL cell viability, which is influenced by the extra-oral time and storage medium. X-rays are taken to evaluate the socket for fractures or remaining debris. The dental team cleans the socket, if necessary, and carefully reinserts the tooth into its correct anatomical position.
The re-implanted tooth is then stabilized using a flexible splint, typically a thin wire or composite material bonded to the adjacent teeth. This splint is designed to hold the tooth in place for approximately one to two weeks, allowing the PDL fibers to begin healing and reattaching to the bone.
Most avulsed permanent teeth require root canal treatment shortly after re-implantation to prevent infection and inflammatory root resorption. Follow-up appointments monitor the tooth for signs of healing or complications like ankylosis (fusion of the tooth root directly to the bone).