title: Parathyroid hormone related to bone regeneration in grafted and nongrafted tooth extraction sockets in rats.
abstract: OBJECTIVE
  The quality and quantity of bone formed in tooth extraction sockets impact implant therapy. Therefore, the establishment of a new approach to enhance bone formation and to minimize bone resorption is important for the success of implant therapy. In this study, we investigated whether intermittent parathyroid hormone (PTH) therapy enhanced bone formation in grafted sockets.
  
  
  METHODS
  Tooth extractions of the maxillary first molars were performed in rats, and the sockets were grafted with xenograft. Intermittent PTH was administered either for 7 days before extractions, for 14 days after extractions, or both. The effect of PTH therapy on bone formation in the grafted sockets was assessed using microcomputed tomography at 14 days after extractions.
  
  
  RESULTS
  PTH therapy for 7 days before extractions was not effective to augment bone fill, whereas PTH therapy for 14 days after operation significantly augmented bone formation in the grafted sockets.
  
  
  CONCLUSIONS
  Intermittent PTH therapy starting right after tooth extractions significantly enhanced bone fill in the grafted sockets, suggesting that PTH therapy can be a strong asset for the success of the ridge preservation procedure.
authors.affiliation: Division of Prosthodontics, Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI 48109-1078, USA.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kuroshima
authors.forename: Zeina
authors.initials: Z
authors.lastname: Al-Salihi
authors.forename: Junro
authors.initials: J
authors.lastname: Yamashita
mesh_terms: D064591:Allografts; D000539:Alveolar Process / Q000187:drug effects; D000818:Animals; D015519:Bone Density / Q000187:drug effects; D001857:Bone Matrix / Q000637:transplantation; D001861:Bone Regeneration / Q000187:drug effects*; D016723:Bone Remodeling / Q000187:drug effects; D018786:Bone Substitutes / Q000627:therapeutic use; D016025:Bone Transplantation; D003094:Collagen / Q000627:therapeutic use; D005269:Femur / Q000187:drug effects; D064593:Heterografts; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008437:Maxilla / Q000187:drug effects / Q000601:surgery; D008903:Minerals / Q000627:therapeutic use; D008963:Molar / Q000601:surgery; D010012:Osteogenesis / Q000187:drug effects; D010281:Parathyroid Hormone / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013977:Tibia / Q000187:drug effects; D013997:Time Factors; D014081:Tooth Extraction; D020390:Tooth Socket / Q000187:drug effects* / Q000601:surgery; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D008903:Minerals; D010281:Parathyroid Hormone; D003094:Collagen