Yes, if a tooth is knocked out, placing it in milk can help preserve it until you can reach a dentist for potential re-implantation. It is important to keep the tooth root moist to improve the chances of successful healing. Do not touch the tooth root, but it can be gently and quickly washed with saline or water. Other alternative options to store a knocked out tooth are saliva or saline. Some pharmacies also sell emergency kits to safely store the tooth while you seek urgent dental care.