title: Delayed intentional replantation of periodontally hopeless teeth: a retrospective study.
abstract: OBJECTIVE
  The purpose of this study was to retrospectively evaluate the survival of periodontally hopeless teeth that were intentionally extracted and replanted after a delay and to compare the radiographic characteristics of the survival group with those of the failure group.
  
  
  METHODS
  The clinical and radiographic data from patients who underwent delayed intentional replantation between March 2000 and July 2010 were reviewed. Twenty-seven periodontally hopeless teeth were extracted and preserved in medium supplemented with antibiotics for 10-14 days. The teeth were then repositioned in the partially healed extraction socket and followed for 3 to 21 months. The radiographic parameters were analyzed using a paired t test and the cumulative survival rate was analyzed using Kaplan-Meier analysis.
  
  
  RESULTS
  Seven replanted teeth failed and the overall cumulative survival rate was 66.4%. In the survival group, the amount of bone loss was reduced from 68.45% to 34.66% three months after replantation. There was radiologic and clinical evidence of ankylosis with 5 teeth. However, no root resorption was found throughout the follow-up period. In the failure group, bone formation occurred from the bottom of the socket. However, a remarkable radiolucent line along the root of a replanted tooth existed. The line lengthened and thickened as time passed. Finally, in each case of failure, the tooth was extracted due to signs of inflammation and increased mobility.
  
  
  CONCLUSIONS
  Delayed intentional replantation has many advantages compared to immediate intentional replantation and could serve as an alternative treatment for periodontally involved hopeless teeth. However, techniques for maintaining the vitality of periodontal structures on the tooth surface should be developed for improved and predictable results.
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Eun-Ung
authors.initials: EU
authors.lastname: Lee
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Hyun-Chang
authors.identifier: 0000-0001-7695-1708
authors.initials: HC
authors.lastname: Lim
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Jung-Seok
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Ui-Won
authors.identifier: 0000-0001-6371-4172
authors.initials: UW
authors.lastname: Jung
authors.affiliation: Microscope Center, Department of Conservative Dentistry and Oral Science Research Center, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Ui-Sung
authors.initials: US
authors.lastname: Kim
authors.affiliation: Microscope Center, Department of Conservative Dentistry and Oral Science Research Center, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Seung-Jong
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Choi
keywords: Alveolar bone loss; Bone remodeling; Periodontal diseases; Survival rate; Tooth replantation