If a mountain biker has a knocked-out tooth, what should you do with the tooth?

The appropriate action to take when dealing with a knocked-out tooth is to pick it up by the chewing surface and gently rinse it with water. This method preserves the tooth as much as possible. It’s crucial to handle the tooth carefully and avoid touching the root, as this part contains living cells that are vital for reattachment if the tooth is to be replanted. Rinsing the tooth gently helps to remove any debris without damaging the delicate structures that may contribute to successful reintegration.

Preserving the tooth in a proper manner increases the likelihood of successful reattachment by a dentist, which is critical for keeping that original tooth. It’s also recommended to keep the tooth moist, ideally in saline solution or milk, which can help keep the tooth's cells alive until professional dental care is obtained. Other options like wrapping the tooth in a cloth or throwing it away do not provide the necessary care and preservation needed for a knocked-out tooth.