title: Impact of different synthetic bone fillers on healing of extraction sockets: an experimental study in dogs.
abstract: OBJECTIVE
  The objective of this study was to elucidate the socket healing process and biodegradation of incorporating synthetic bone fillers followed by grafting of the fresh extraction socket.
  
  
  METHODS
  Third premolars in four quadrants of eight beagle dogs were extracted and randomly treated with either one of hydroxyapatite (HA), biphasic calcium phosphate (BCP), β-tricalcium phosphate (β-TCP), or no graft (C). Histologic observations and histomorphometric analysis at three zones (apical, middle, and coronal) of the socket were performed. Socket area (S) and the proportions of newly formed bone (%NB), residual biomaterials (%RB), and fibrovascular connective tissue (%FCT) at 2, 4, and 8 weeks were measured. The numbers of osteoclast-like multinucleated cells (No.OC) were also determined at the three zones.
  
  
  RESULTS
  %NB was significantly higher in control group compared with the grafted groups at all healing periods. %NB of HA and BCP increased with time, whereas %RB showed different patterns that decreased in BCP, unlike the minimal change observed in HA. %NB of β-TCP showed smallest portion compared with other grafted groups at 2 and 4 weeks, however, significantly increased at 8 weeks. %RB of β-TCP was less than HA and BCP at all healing periods. Numbers of multinucleated cells were greater in BCP and β-TCP, followed by HA and smallest in control group.
  
  
  CONCLUSIONS
  Within the limit of this study, bone formation of the extraction socket was delayed in the sockets grafted with synthetic bone fillers and showed different healing process according to the biodegradation patterns.
authors.affiliation: Department of Periodontology, Graduate School of Medicine, Ewha Womans University, Seoul, South Korea.
authors.forename: Ji-Youn
authors.initials: JY
authors.lastname: Hong
authors.forename: Jung-Seok
authors.initials: JS
authors.lastname: Lee
authors.forename: Eun-Kyoung
authors.initials: EK
authors.lastname: Pang
authors.forename: Ui-Won
authors.initials: UW
authors.lastname: Jung
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Choi
authors.forename: Chong-Kwan
authors.initials: CK
authors.lastname: Kim
mesh_terms: D000818:Animals; D001641:Bicuspid; D018786:Bone Substitutes / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000494:pharmacology*; D004285:Dogs; D006882:Hydroxyapatites / Q000494:pharmacology*; D008297:Male; D010010:Osteoclasts / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology*; D010784:Photomicrography; D014081:Tooth Extraction; D020390:Tooth Socket / Q000502:physiology* / Q000601:surgery; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D006882:Hydroxyapatites; C485817:beta-tricalcium phosphate; C074950:hydroxyapatite-beta tricalcium phosphate