If a tooth has been knocked out or broken off, place it in cold pasteurized milk immediately. Milk keeps the living cells on the tooth’s root surface viable for up to two hours, buying you critical time to reach a dentist. The single biggest mistake people make is letting the tooth dry out or dropping it in tap water, both of which destroy the cells needed for successful reimplantation.
Why Storage Liquid Matters
A knocked-out tooth isn’t dead tissue like a fingernail clipping. The root is covered in a thin layer of living cells called the periodontal ligament, and these cells are what allow a dentist to reattach the tooth to your jawbone. For reimplantation to work, those cells need to stay alive, which means they need to stay moist in a liquid that matches the salt concentration and acidity of your body’s own fluids.
Tap water is one of the worst choices because it has almost no dissolved salts. When cells sit in plain water, fluid rushes into them through their membranes, causing them to swell and burst. This process is irreversible. Letting the tooth air-dry is equally destructive: once those root cells dehydrate, no amount of rehydration will bring them back. Even a few minutes of dry storage significantly lowers the odds of saving the tooth.
Best Liquids, Ranked
The gold standard is a product called Hank’s Balanced Salt Solution, a sterile solution with a pH of 7.2 and a salt concentration that closely matches human body fluids. It can preserve root cells for up to 24 hours when kept cold. The American Association of Endodontists recommends it as the top choice. Some schools, sports facilities, and first aid kits stock it under brand names like Save-A-Tooth.
For most people in an emergency, though, cold pasteurized milk is the practical winner. Its pH (6.5 to 7.2) and salt concentration closely match the conditions those root cells need to survive. Milk also contains amino acids, carbohydrates, and vitamins that nourish the cells. It’s bacteria-free when sealed, and it’s available in nearly every refrigerator or convenience store. At a cellular level, milk performs nearly as well as the balanced salt solution, though its effectiveness drops after about two hours.
Other options, in rough order of effectiveness: saliva (placing the tooth in your cheek or under your tongue), saline solution, coconut water. All of these are better than tap water or dry storage. Saliva works because it has a compatible salt balance, though bacteria in the mouth make it less ideal than milk for longer storage times.
How to Handle the Tooth
Pick it up by the crown only. The crown is the white part you’d normally see in your mouth when chewing. Never touch the root, which is the yellowish, tapered end that sits below the gumline. Even light handling of the root can damage or strip away the delicate living cells you’re trying to preserve.
If the tooth fell on the ground and has visible dirt on it, give it a gentle rinse with milk, saline, or saliva. Do not scrub it, do not use soap, and do not dry it with a cloth or paper towel. You’re just removing loose debris, not sterilizing it. A few seconds of gentle rinsing is enough. Then drop it into your storage liquid immediately.
Try to Reimplant It Yourself
If you’re dealing with a whole tooth that came out cleanly (not a fragment), the best storage container is actually the socket it came from. After gently rinsing off any dirt, hold the tooth by the crown and slide it back into the empty socket, root end first. Bite down gently on a clean cloth or gauze to hold it in place, then get to a dentist as quickly as possible.
This works because the socket provides a perfect environment: the right temperature, the right moisture, and direct contact with the bone and tissue where the tooth belongs. Every minute a tooth spends outside the socket reduces the chance of successful reimplantation.
Storing a Tooth Fragment
Not every dental emergency involves a completely knocked-out tooth. If a piece of your tooth chipped or broke off, the situation is different. A fragment can’t be reimplanted in the same way, but a dentist may still be able to bond it back on for a better cosmetic result than a synthetic filling. Place the fragment in milk or saline just as you would a whole tooth, and bring it to your appointment. Even if the fragment can’t be reused, it helps your dentist understand the fracture pattern and plan the repair.
If you can’t find the broken piece, that’s okay. Modern bonding materials and crowns can restore the tooth’s shape and function. The fragment is a bonus, not a requirement.
Baby Teeth Are Different
If a child’s baby tooth gets knocked out, do not try to reimplant it. Forcing a baby tooth back into the socket can damage the developing permanent tooth underneath. Avulsion happens most often in children between ages 7 and 9, when roots are still developing and the surrounding bone is softer. If the knocked-out tooth is a baby tooth, control the bleeding with gentle pressure, save the tooth to confirm it’s a primary tooth (they’re smaller and whiter than permanent teeth), and see a dentist promptly. Reimplantation guidelines apply only to permanent adult teeth.
The Time Window
Speed matters more than almost anything else. A tooth reimplanted within 30 minutes has the highest chance of long-term survival. After 60 minutes outside the mouth, success rates drop sharply, even with ideal storage. If you’re using milk, you have roughly a two-hour window before it stops effectively preserving root cells. The balanced salt solution extends that to around 24 hours at refrigerator temperature, but that’s a backup plan, not a reason to delay treatment.
Your priority should be: pick up the tooth by the crown, rinse gently if dirty, place it in milk (or reimplant it yourself), and get to a dentist or emergency room within the hour. Calling ahead lets the dental office prepare for an urgent reimplantation, which saves valuable minutes once you arrive.