Dear Dr. Mady: I have a four-year-old daughter who fell off of her bike this week and completely knocked out one of upper front baby teeth, root and all. I put the tooth in milk and rushed her to our dentist immediately and he would not re-implant it. I have always heard that a tooth can be re-implanted right away so I am wondering if it could have been and if you think that the permanent tooth replacing it in the future will be affected? - Darlene in Wheatley
Dear Darlene: I have to agree with your dentist about the decision to not re-implant the tooth. Generally, there is no attempt made to re-insert primary teeth that are completely avulsed (knocked out). If the dentist tries to do this, the permanent teeth underneath could be affected in a negative way.
If a decision is made to re-implant a primary tooth, this may lead to a condition known as ankylosis. This means that this baby tooth's root has become "bonded" to the bone. This fusion results in the baby tooth not being exfoliated (lost) on time or on it's own and the permanent tooth eruption may be halted or altered.
It is also important to understand that if your dentist chose to do this, the necrosis (breakdown caused by death) of the nerve and blood supply attachment of the tooth that was severed at the time of trauma can, lead to infection of varying degrees. Some amount of these tissues does remain within the roots if root canal therapy is not done and it is not always initiated on deciduous (primary) teeth. This infection can disturb the formation and eruption of permanent or secondary teeth.
Although the chances are slim, some damage may be done to the permanent teeth from the avulsion alone. This is possible if the root of the baby tooth is directly against the enamel crown of its successor. A defect in the crown of this tooth may occur and result in a missing, decalcified or discolored area of enamel. If the trauma is severe enough, the roots of the permanent tooth may even become damaged.
Normal eruption of the front upper adult tooth is seven or eight years of age. This premature loss of the baby tooth may result in a delay of another year or two before the eruption of the adult tooth that will follow. This is especially true if the root of the tooth in question is damaged before it is even half-way formed. The permanent tooth usually erupts when it's root is two-thirds formed.
Overall, re-implantation of primary teeth is rarely successful and if the permanent tooth appears to not be erupting on time in the future, then surgical exposure and intervention is an option. Make sure that your child sees your dentist again soon and at regular intervals so that not only the healing can be observed but also to assess whether or not any difficulties are approaching. Good luck and I hope your daughter is doing fine now!
This column is reprinted with the permission of the author and The Windsor Star. "Ask the Dentist" is written by Windsor dentist (and ECDS member), Dr. David Mady Jr.. The column appears the first Thursday of each month in the Windsor Star. Readers with questions can write to "Ask The Dentist", c/o The Windsor Star, 167 Ferry St., Windsor Ontario, N9A 4M5