歯の凍結長期保存に関する実験的研究

抄録

In order to clinically utilize teeth that have been preserved for a long period of time, teeth were frozen at either -0.5 or -1℃/min in the cryoprotective agents DMSO, glycerol, or trehalose and stored at -196℃ for 2 weeks. Cellular proliferation and adhesion were evaluated in vitro. Eight weeks after the cryopreserved teeth had been grafted in vivo, X-ray and histological evaluations were assessed and compared. Cell proliferation and adhesion studies showed that cellular activity was most favorable when teeth were cryopreserved with physiological saline＋ glycerol or physiological saline＋DMSO, followed by physiological saline＋ trehalose and physiological saline, in that order. Also, the results were generally more favorable when teeth were frozen at the rate of -1℃/min compared to the rate of -0.5℃/min.
Morphological examinations showed that teeth cryopreserved with physiological saline＋ glycerol or physiological saline＋ DMSO had more favorable development of cellular processes and more active cellular proliferation. In histological examinations, teeth cryopreserved with physiological saline or physiological saline＋ trehalose showed adhesion between the dentin and the alveolar bone all around the dental root. In teeth cryopreserved with physiological saline＋ DMSO or physiological saline＋ glycerol, fibrous connective tissue was seen at the border between the grafted teeth and the alveolar bone. The results suggest that the gradual freezing of teeth at the rate of -1℃/min using glycerol or DMSO as a cryoprotective agent was extremely effective and could be applicable in routine clinical treatments.