Transient apical breakdown and its relation to color and sensibility changes after luxation injuries to teeth

Abstract In examining a population of 637 luxated permanent teeth, it was found that 27 teeth (4.2%) demonstrated apical breakdown in the form of either a pronounced radiolucency which appeared spontaneously some time after injury, or a persistent expansion of the periodontal ligament space (PDL) over an extended interval after injury, which at later follow-up controls had either returned to normal without further radiographic change or was accompanied by surface resorption and/or pulp canal obliteration without intervening treatment. Two of the 27 teeth demonstrated radiographic change alone, while the remaining 25 demonstrated color and/or electrometric sensibility-changes as well. Twenty-three teeth had fully-formed roots whose apices were either closed or half-closed at the time of injury. Five had roots which were fully formed, but with an open apex; the remaining tooth had three-quarter root formation. The injuries were moderate, the majority being extrusion or lateral luxation, affecting both pulpal and periodontal structures. Based on clinical findings, the following hypothesis is proposed: Transient apical breakdown appears to be a phenomenon linked to the repair processes in the traumatized pulp or pulp and periodontium of luxated mature teeth which returns to normal when repair is complete. Whether this is related to a transitory infection and/ or removal of necrotic traumatized tissue cannot be evaluated from the material available.