Broken permanent tooth — Broken permanent teeth can usually be repaired successfully. For the best possible outcome, the child should see a dentist for treatment within one week of the injury. Broken teeth that are sensitive to hot or cold need to be treated urgently. Tooth fragments should be saved, if possible, and stored in tap water so they can be reattached. If tooth fragments cannot be found, the tooth may be repaired with a material called composite resin, which can be matched to the color of the natural tooth.http://www.uptodate.com/contents/patient-information-mouth-and-dental-injuries-in-children