Endodontic Microsurgery for an Immature Permanent Lower Premolar: A Case Study

抄録

 Immature teeth are roots that have not completely formed. Once the pulp of an immature tooth has become devitalized, there is no prospect of root development, and since the root is short and the tooth structure thin, it is at higher risk of fracture. However, treatment to enable the long-term preservation of teeth that have become diseased is important for the stability of the dentition and to maintain occlusal function.

 Case: A boy, aged 11 years 10 months, presented with the chief complaint of swelling of the gingiva in the lower left premolar region. Dental X-rays showed that the root of the lower left second premolar was not completely formed, and a periapical radiolucency was evident from the apex to the central part of the root. A radio-opacity thought to be a dentin bridge was seen at the root canal foramen, and partial pulpotomy had been conducted in the vicinity of the tooth neck in previous treatment. There was no vital response on electric pulp testing. It was thought that, despite vital pulp therapy, the pulp of the lower left second premolar had become devitalized, and periapical periodontitis had occurred. Given the results of these investigations, The diagnosis was based on AAE criteria. Pulpal diagnosis was pulp necrosis, and apical diagnosis was chronic apical abscess.

 Pulp necrosis and chronic apical abscess was diagnosed. Since the root formation of this tooth was incomplete, we decided to conduct apexification, but with no evident improvement in symptoms. Cone-beam computed tomography (CBCT) was performed to clarify the root canal morphology. Diagnostic imaging with CBCT showed that there was a transverse fracture of this root near its apex. In axial section, a radio-opacity believed to be the lesion extended to the root of the left first premolar and the mesial root of the left first molar. Because the condition was not cured by regular root canal treatment, it was decided to conduct endodontic microsurgery.

 Course: There were no symptoms after two years. The patient continues to heal, since X-rays show that the radiolucency has contracted.

 Conclusion: Based on the findings of CBCT, endodontic microsurgery of an immature tooth with failed vital pulp therapy was performed and achieved adequate functional recovery following a good postoperative course.