title: Effect of fibroblast growth factor on injured periodontal ligament and cementum after tooth replantation in dogs.
abstract: OBJECTIVE
  The purpose of this animal study was to perform a histological and histomorphometric analysis in order to elucidate the effect of fibroblast growth factor-2 (FGF-2) on injured periodontal ligament (PDL) and cementum after tooth replantation in dogs.
  
  
  METHODS
  The roots of 36 mandibular premolars from six mongrel dogs were used in this study. The roots were randomly divided into three groups: (1) a positive control group (n=12), in which the PDL was retained; (2) a negative control group (n=12), in which the PDL and the cementum between the notches were removed; and (3) an experimental group (n=12), in which the PDL and the cementum between the notches were removed and the roots were soaked in an FGF-2 solution (30 µg/0.1 mL). After treating the root surfaces, the extracted roots were replanted into extraction sockets. The animals were sacrificed four and eight weeks after surgery for histologic and histomorphometric evaluation.
  
  
  RESULTS
  At four and eight weeks, normal PDLs covered the roots in the positive control group. In the negative control group, most replanted roots showed signs of replacement resorption. In the experimental group, new PDL-like tissue and cementum-like tissue were observed to partially occupy the region between the root surfaces and the newly formed bone. Histomorphometric analysis showed that the mean length of the newly formed cementum-like tissue on the roots treated with FGF-2 was significantly greater than that of the tissue on the roots in the negative control group (four weeks, P=0.008; eight weeks, P=0.042). However, no significant differences were observed between the roots treated with FGF-2 and the negative control roots with respect to newly formed PDL-like tissue.
  
  
  CONCLUSIONS
  The results of this study suggest that use of FGF-2 on injured root surfaces promotes cementogenesis after tooth replacement in dogs.
authors.affiliation: Department of Periodontology, School of Dentistry, Chosun University, Gwangju, Korea.
authors.forename: Sang-Joun
authors.initials: SJ
authors.lastname: Yu
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Jung-Seok
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Ui-Won
authors.initials: UW
authors.lastname: Jung
authors.affiliation: Department of Oral Histology-Developmental Biology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea.
authors.forename: Joo-Cheol
authors.initials: JC
authors.lastname: Park
authors.affiliation: Department of Periodontology, School of Dentistry, Chosun University, Gwangju, Korea.
authors.forename: Byung-Ock
authors.initials: BO
authors.lastname: Kim
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Choi
keywords: Cementogenesis; Growth factor; Periodontium; Regeneration; Tooth replantation