title: In-vitro and in-vivo study of periodontal ligament cryopreserved with a magnetic field.
abstract: BACKGROUND
  The purpose of this study was to examine the effect of a new cryopreservation method with a magnetic field on periodontal regeneration in vitro and in vivo.
  
  
  METHODS
  Human periodontal ligament cells were frozen in 10% dimethyl sulfoxide by using a programmed freezer with a magnetic field. Cells were cryopreserved for 3 days at -150°C. Immediately after thawing, collagen type I and alkaline phosphatase gene expression were determined by real-time polymerase chain reaction. Incisors were extracted from 15-week-old Wistar rats and cryopreserved or dried for 3 days. Then the incisors were replanted into the same sockets. Ninety days after transplantation, they were observed under light microscopy.
  
  
  RESULTS
  There was no difference in the messenger RNA expression of collagen type I between the cryopreserved and the control groups. The expression of alkaline phosphatase messenger RNA in the cryopreserved group was slightly decreased compared with the control group. There was no progressive root resorption in the teeth that were replanted immediately (control group) or cryopreserved. However, there was widespread root resorption and ankylosis in the dried teeth.
  
  
  CONCLUSIONS
  These results show that a magnetic field programmed freezer can be successfully used for cryopreservation of teeth.
authors: Department of Orthodontics and Craniofacial Developmental Biology, Graduate School of Biomedical Science, Hiroshima University, Hiroshima, Japan.
authors: Hiroko
authors: H
authors: Kamada
authors: Masato
authors: M
authors: Kaku
authors: Toshitsugu
authors: T
authors: Kawata
authors: Hiroyuki
authors: H
authors: Koseki
authors: Sara
authors: S
authors: Abedini
authors: Shunichi
authors: S
authors: Kojima
authors: Akemi
authors: A
authors: Sumi
authors: Masahide
authors: M
authors: Motokawa
authors: Tadashi
authors: T
authors: Fujita
authors: Junji
authors: J
authors: Ohtani
authors: Norio
authors: N
authors: Ohwada
authors: Kazuo
authors: K
authors: Tanne
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000096:biosynthesis; D000818:Animals; D002470:Cell Survival; D002478:Cells, Cultured; D024042:Collagen Type I / Q000096:biosynthesis; D015925:Cryopreservation / Q000379:methods*; D015870:Gene Expression; D006801:Humans; D060526:Magnetic Fields; D008297:Male; D009926:Organ Preservation / Q000379:methods*; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D012391:Root Resorption / Q000517:prevention & control; D014090:Tooth Replantation
chemical_list: D024042:Collagen Type I; D012333:RNA, Messenger; D000469:Alkaline Phosphatase