Autotransplantation of a Tooth Cryopreserved Over 11 Years Using a Programmed Freezer With a Magnetic Field: A Case...

This case report shows an autotransplantation of the lower right cryopreserved third molar into the extraction socket of the lower right first molar. Due to deep caries of the lower right first molar, the mesial root of this tooth was extracted. The patient asked to keep the distal root of the lower right first molar even if the root can survive only for a short period. So, a fixed partial denture supported by the lower right second premolar and the distal root of the lower right first molar was set. However, it was supposed that the distal root of the lower right first molar as an abutment tooth had a poor prognosis. Therefore, we also extracted the lower right third molar and cryopreserved to prepare autotransplantation if the lower right first molar has to be removed in the future. At first, the extracted third molar was frozen using a programmed freezer with a magnetic field named "Cells Alive System" (CAS) freezer, which was developed for tissue cryopreservation, and then, cryopreserved in the -150°C deep freezer. Eleven years later from the cryopreservation of the third molar, the lower right first molar showed root fracture. So, we extracted the lower right first molar and autotransplanted the cryopreserved third molar. Three years later, the autotransplanted tooth continued to be stable with healthy periodontium. The present case revealed that autotransplantation of a long-term cryopreserved tooth in a CAS freezer is a variable method to replace missing teeth.