Inside Dental Assisting
Treating Knocked-Out Teeth in the Dental Office
Paul R. Krasner, DDS
Knocked out (avulsed) teeth are true dental emergencies, and they can wreak havoc on an office schedule. This is because how they are treated within the first 60 minutes of the accident often determines long-term success or failure. All knocked out teeth can be replanted in their sockets, but whether the procedure is successful or not depends on how they are handled prior to the re-implantation. One advanced technology, the Save-A-Tooth® system (www.saveatooth.com), can remove a very jagged peak in a schedule that may already be filled with peaks and valleys.
All teeth are attached to their socket by the periodontal ligament. When a tooth (or teeth) are hit hard enough—like with a baseball, hockey stick, or the pavement—at just the right angle, the tooth will pop out, like a cork from a bottle. The periodontal ligament will stretch like a rubber band and will split in half; half will stay on the root surface and half stays attached to the socket wall. If these two halves can be kept alive, when the tooth is replanted they will knit back together and a new periodontal ligament will re-form.1
The half that stays on the socket wall is not a problem to keep alive. It is still attached to its blood supply and is protected by the boney walls of the socket. However, the half that stays on the root surface must be protected from dying at all costs. When a patient calls or shows up in the office with a knocked out tooth, the office must shift into an emergency mode. The patient must be told three things when they call:
Don’t touch the tooth root.
Place the tooth in saline solution like Hank’s Balanced Salt Solution (more about that later).
Place the tooth in a soft-sided container with a tightly fitting top.
How to Prevent Crushing the Tooth
The cells on the tooth root are very delicate and even touching them with fingers can be damaging. Many laypeople panic at the moment of an accident and take actions that appeal to common sense, such as placing the knocked out tooth in a tissue or ice, while in reality these steps can be very damaging to the tooth’s chances of survival. Either of these actions will actually kill the tooth root cells and lower the incidence of success following their re-implantation. Urban legends have sprung up on how to store knocked-out teeth, such as placing them in the mouth between the gum and cheek. This is a treatment that was developed 50 years ago when scientific methods for storing knocked out teeth weren’t available. This may be one of the worst things to do, second only to placing the teeth in a tissue. Here are the problems: First, saliva is filled with bacteria and infects the tooth cells, and second, the tooth may get swallowed. Third, the concentration of saliva is toxic to the cells, and fourth, the patients may accidentally bite the teeth. Ever try and keep a marble in your mouth for even a minute?
Keeping the Cells Nourished
Remember, once it’s out of the socket, the tooth loses its blood supply. A normal cell keeps 15 minutes’ worth of stored nutrients. After 15 minutes, the cell begins to die, and after 60 minutes it will essentially be dead. Dead cells cannot knit back with the cells on the socket wall and the root will slowly be eaten away (resorbed) until, 6 months to 2 years later, it is completely gone.
So the key factor in keeping cells nourished is providing a storage fluid that can replenish the used-up nutrients. There is only one fluid that can do this. It is called Hank’s Balanced Salt Solution (HBSS).2 It is a scientific fluid (not a saltwater mix) that provides all of the nutrients and the correct cell pressure to keep cells alive. It is the most commonly used fluid in medical research. Knocked out teeth placed in HBSS can be kept alive for at least 24 hours. Even more importantly, teeth that have been out of the mouth for an hour can have their depleted nutrients completely replenished, restoring the cell to complete functionality if placed in HBSS for 30 minutes prior to re-implantation.
Milk as a Storage Medium
Milk is a good substitute as a storage medium for knocked out teeth when HBSS isn’t available. Milk’s main benefit is that it doesn’t destroy tooth root cells; however, it doesn’t have the ability to re-nourish them, either. Milk was a good storage medium 30 years ago but it has been replaced by far superior techniques, such as Save-A-Tooth.
Saving a Tooth When it Arrives in the Office
The journey from the site of an accident where teeth are knocked out is like Dorothy’s trip on the yellow brick road: anything and everything that could irreversibly damage the teeth can happen: teeth can fall out of glasses, the storage fluid can spill out, the root cells can be crushed during removal from the carrying container. Save-A-Tooth is a six-part system that contains a HBSS and protects the teeth from “cradle to re-implantation.” When teeth arrive in the dental office, they should immediately be transferred to a Save-A-Tooth. This will permit replenishment of the lost nutrients and provide healthy cells that can knit back to the healthy cells on the socket wall. From a scheduling standpoint, Save-A-Tooth is crucial. Without it, time is critical and rules everything that is done. All other patients have to be pushed back, panicky parents can’t be thoroughly counseled about the ramifications of this terrible injury, and terrified kids can’t be calmed down. With a Save-A-Tooth, time is irrelevant. The office has 24 hours in which all of the above can be addressed. Good advice for all of your patients with children is to have a Save-A-Tooth system at home—telling them to have it ahead of time is like a physician telling patients to have an EpiPen on hand at all times when their child has severe allergies because oral Benadryl is not the best line of defense for a bee sting.
The consequences of a knocked-out tooth are serious and can last a lifetime. For a 7-year-old who loses two front teeth, the dental problems are monumental. Because their jaws will be developing and growing until they are 18, they can’t even benefit from such ordinary dental remedies as fixed bridges or implants. These children are condemned to 11 years of continual changing dental remedies such as flippers—which, as we all know, can be uncomfortable and, at times, socially embarrassing—at one of the most socially sensitive times in their life. By being prepared for knocked out teeth, not only can the scheduling craziness associated with their treatment be avoided, but also the chances of making an enormous difference in a child’s life can be greatly increased.
1. Krasner P, Rankow H. New philosophy for the treatment of avulsed teeth. Oral Surg Oral Med Oral Pathol. 1995;79:616-623.
2. Blomlof L. Milk and saliva as possible storage media for traumatically exarticulated teeth prior to replantation. Swed Dent J. 1981;Suppl 8.
3. Cvek M, Cleaton-Jones P, Austin J. Effect of topical application of doxycycline on pulp revascularization and periodontal healing in reimplanted monkey incisors. Endodon Dent Traumatol. 1990;6(4):170-176.
Dr. Krasner has received financial compensation from Save-A-Tooth.
About the Author
Paul R. Krasner, DDS
Clinical Associate Professor
Temple University School of Dentistry
Private Practice in Endodontics