The knocked-out permanent tooth: information for patients, parents and caregivers.

Before the accident, the tooth was held in place by fibres and cells called the periodontal ligament. The fibres were torn apart and many of the cells were damaged, either by the accident or because of the length of time out of the mouth. If the tooth has been out of the mouth more than 5 minutes, it will never be the same again. That means that if it is put back in, it will have to be extracted sooner or later.