title: [Application of xenograft for alveolar ridge preservation in posterior sites: a randomized controlled clinical trial].
abstract: OBJECTIVE
  To investigate the effect of ridge preservation with Bio-Oss Collagen and Bio-Gide in posterior sites.
  
  
  METHODS
  From May 2010 to July 2013, 16 patients with bilateral posterior teeth planned to be extracted and replaced by implants were enrolled. One of the sockets was randomly selected and presserved with Bio-Oss Collagen and Bio-Gide (intervention group). The contralateral socket was left to heal spontaneously (control group). Cone-beam (CBCT) scans were performed immediately after the extraction and 6 month later. The bone cores were collected during the implant placement surgery and analyzed by micro-computed tomography.
  
  
  RESULTS
  After 6 month healing, the vertical and horizontal dimensional alteration of the treatment group were (0.55 ± 1.05) mm and (-0.99 ± 0.94) mm respectively, while the vertical and horizontal change of control group were (-0.71 ± 1.41) mm and (-2.26 ± 1.29) mm respectively. The micro-computed tomography results showed that there was no significant difference in new bone volume between control and intervention groups.
  
  
  CONCLUSIONS
  Applying Bio-Oss Collagen and Bio-Gide for ridge preservation in posterior sites resulted in less vertical and horizontal bone resorption of sockets following extraction.
authors.affiliation: Department of Implant Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Lei
authors.affiliation: Department of Implant Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Implant Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China; Email: yorcklin@263.net.
authors.forename: Ye
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Implant Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Di
authors.affiliation: Department of Implant Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Implant Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Xiulian
authors.initials: X
authors.lastname: Hu
mesh_terms: D000539:Alveolar Process / Q000000981:diagnostic imaging; D001672:Biocompatible Materials / Q000627:therapeutic use*; D001862:Bone Resorption / Q000517:prevention & control*; D003094:Collagen / Q000627:therapeutic use*; D064593:Heterografts; D006801:Humans; D008903:Minerals / Q000627:therapeutic use*; D059351:Organ Sparing Treatments / Q000379:methods*; D014081:Tooth Extraction; D014945:Wound Healing; D055114:X-Ray Microtomography
chemical_list: C106416:Bio-Gide; C077540:Bio-Oss; D001672:Biocompatible Materials; D008903:Minerals; D003094:Collagen