▪ What information would you want from the school nurse?

Are there any other injuries? It should be established whether there has been any loss of consciousness or signs of concussion. Disorientation and impaired response to simple questions may indicate a brain injury that would require immediate hospital assessment. Limb extremity injuries are common in playground accidents, and the school nurse should be asked to establish whether there is any suspicion of limb fracture or lacerations that require suturing. Dealing with these might be a higher priority than the avulsed tooth.

Is there any relevant medical history? Reimplantation of an avulsed tooth is contraindicated in a child predisposed to infective endocarditis. Any known clotting defect could result in problematic bleeding from a tooth socket.

Has the child an up-to-date tetanus immunization? The school should have a record of immunization status, with particular reference to antitetanus immunization.

Have the parents been informed? Ideally the parents should be notified of the injury and of any intended treatment prior to it being carried out. If at all possible, a parent or legal guardian should be encouraged to either accompany the child or to meet at your practice (or hospital if indicated by other injuries).

What age is the child? The age will determine whether the tooth is primary or permanent and, if permanent, the likely stage of root development.

Is the tooth intact? This is difficult for a lay person to ascertain, but you should ask the caller to carefully examine the tooth, ideally without touching it, or at least without touching the root. A crown fracture would be easier to describe than a root fracture, but if a tapering root of approximately 2 cm in length is present, the tooth is probably intact.

Is the root contaminated with dirt or debris? The root surface must be visibly clean prior to any attempt at reimplantation. Dirt on the root must be cleaned off though any asphalt or gravel ‘tattoo’ on the incisal edge is not relevant at this stage.

▪ What advice can you safely give over the telephone?

Keep the tooth wet. The first advice should be to place the tooth in a cup of cold fresh milk. Storage in tap water is undesirable, as its hypotonicity reduces viability of the periodontal ligament cells adhering to the root.

Clean off visible contaminants. Rinse the root gently under cold running water for a maximum of 10 seconds to remove dirt from the root surface. The tooth will be slippery to hold but it should be held by the crown only, and under no circumstances should the root surface be scrubbed or scraped. Debris that does not rinse off may be carefully dabbed off with a clean, ideally sterile, cotton-wool bud.

If you can, reimplant the tooth straight away. The speed with which the tooth is replanted is the most important factor in determining a favourable outcome following replantation. A responsible adult should reimplant the tooth without further delay. It should be emphasised to the caller that it is relatively simple to reimplant the tooth and that they should be encouraged to try. The tooth should be placed back in the socket with firm gentle pressure until it is at the same level as the adjacent incisor and orientated labiopalatally. Reasons for failure are likely to be insufficient confidence, a distressed uncooperative child or a fracture of the socket wall. If the tooth cannot be reimplanted, you should advise that the child be escorted to a dentist as soon as possible.

▪ How should the tooth be transported and why?

A successful outcome requires that the remnants of the periodontal ligament adhering to the root remain viable because after replantation the healed ligament will prevent replacement resorption and ankylosis. An appropriate transport medium is essential and the key parameter is its osmotic pressure. It has been shown that the periodontal ligament will survive if stored for only a few minutes in water, for up to 30 minutes in saliva, and up to 60 minutes in cold milk. Saliva is thus useful but it is inadvisable to ask an injured child to hold an avulsed tooth in their mouth for any period because of the risk of it being swallowed or inhaled. Storing dry or using water is to be avoided.