What is tooth avulsion?
Dental avulsion is the complete displacement of a tooth from its socket into the surrounding bone owing to any traumatic injury. The treatment for permanent teeth consists of replantation, immediately if possible. Deciduous teeth should not be replanted due to the risk of damaging the permanent tooth germ. Immediate replantation ensures the best possible prognosis but may not always possible since more serious injuries may be present which needs attention.
What to do when a tooth is knocked out?
Do not touch the root or clean the tooth. Handle the tooth by the crown only. You should attempt replantation i.e. physically placing the tooth back into its socket, immediately if possible. If it is less than 5 minutes of injury then immediate replantation has the best prognosis. The tooth should be cleaned before replantation. The proper way to remove debris from the root of an avulsed tooth is to rinse it in cold water (either tap or clean bottled water), being careful not to scrub or scrape it. If the root appears clean, grasp the crown between your thumb and first finger with the smooth flat surface forward. Then push firmly and hold the tooth in place.
Sustained pressure is required to move blood that has accumulated in the socket. When the tooth is seated into its original position, it must be held there by hand or with a wad of wet tissue to keep it from extruding from the socket.
If, for any reason, the tooth cannot be replanted immediately then the patient and the tooth needs to be carried soon to the dentist in a proper preserving carrier media. This media can be cold milk or the patient’s own saliva and the intention is to prevent the tooth from drying.
What can be the maximum time period for replanting the knocked out tooth?
Importance of the replanting the tooth in less than 5 minutes: Immediate replacement of tooth within 5 minutes is the most important factor for long-term survival of knocked out (avulsed) teeth.
Beyond 15 minutes: Storage/transportation in cold milk or the patient's own saliva will prevent the avulsed tooth from drying. If replantation of the avulsed tooth takes a fairly longer time then it affects the ability to regenerate periodontal ligament cells — the living cells on the root surfaces that connect them to the bone of the tooth socket. The long term outcome is then less favorable.
By and beyond 12 hours: Avulsed tooth replanted by and beyond 12 hours has the least chances of survival. It causes a fusion of the tooth to bone (ankylosis) followed by gradual root resorption (dissolving away) and tooth loss over a few years. The tooth will survive for a period for time but ankylosis and/or resorption are inevitable.
Summary: Any permanent tooth that is avulsed should be replanted as soon as possible. Teeth replanted in pre-adolescents typically show shorter survival times than replantation in young adults because of the impact of the growth process and the enhanced cellular activity.
How to manage the knocked out primary teeth?
Primary teeth are managed differently from adult teeth and are generally not replanted as primary teeth are concerned for the normal eruption of the underlying permanent tooth. Replanting primary teeth may cause infection to spread to the developing permanent tooth or interfere with the normal time sequence of the permanent tooth erupting into the mouth. The more important consideration is to retain space occupied by the lost primary molars that act as guides for erupting permanent teeth. Therefore, more important than replantation is to allow your dentist to determine how to maintain the space the primary tooth had occupied earlier. This may prevent the need for orthodontic treatment to correct the situation later.