title: Healing of ungrafted and grafted extraction sockets after 12 weeks: a prospective clinical study.
abstract: OBJECTIVE
  In this prospective study, bone formation in human extraction sockets augmented with Bio-Oss Collagen after a 12-week healing period was quantified and compared to bone formation in unaugmented extraction sockets.
  
  
  METHODS
  Selected patients with four-walled extraction sockets were included in this prospective study. After extraction, the sockets were randomly augmented using Bio-Oss Collagen or left to heal unfilled without raising a mucoperiosteal flap. At the time of implant placement, histologic specimens were obtained from the socket and analyzed. Statistical analysis was performed using the Wilcoxon signed-rank test.
  
  
  RESULTS
  Twenty-five patients with a total of 39 sockets (20 augmented, 19 unaugmented) were included in the study and the histologic specimens analyzed. All specimens were free of inflammatory cells. The mean overall new bone formation in the augmented sites was 25% (range, 8%-41%) and in the unaugmented sockets it was 44% (range, 3%-79%). There was a significant difference in the rate of new bone formation between the grafted and ungrafted sockets and a significant difference in the bone formation rate in the apical compared to the coronal regions of all sockets, independent of the healing mode.
  
  
  CONCLUSIONS
  This descriptive study demonstrated that bone formation in Bio-Oss Collagen-grafted human extraction sockets was lower than bone formation in ungrafted sockets. Bone formation occurred in all specimens with varying degrees of maturation independent of the grafting material and was initiated from the apical region.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Clinical Navigation and Robotics, Charité-Campus Virchow Clinic, Berlin, Germany. susanne.nahles@charite.de
authors.forename: Susanne
authors.initials: S
authors.lastname: Heberer
authors.forename: Bassem
authors.initials: B
authors.lastname: Al-Chawaf
authors.forename: Carlo
authors.initials: C
authors.lastname: Jablonski
authors.forename: John J
authors.initials: JJ
authors.lastname: Nelson
authors.forename: Hermann
authors.initials: H
authors.lastname: Lage
authors.forename: Katje
authors.initials: K
authors.lastname: Nelson
mesh_terms: D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000473:pathology; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology; D001857:Bone Matrix / Q000637:transplantation; D016723:Bone Remodeling / Q000502:physiology; D018786:Bone Substitutes / Q000627:therapeutic use*; D003094:Collagen / Q000627:therapeutic use; D004396:Coloring Agents; D003238:Connective Tissue / Q000473:pathology; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008334:Mandible / Q000473:pathology / Q000601:surgery; D008437:Maxilla / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D008903:Minerals / Q000627:therapeutic use; D010012:Osteogenesis / Q000502:physiology; D011446:Prospective Studies; D014081:Tooth Extraction; D020390:Tooth Socket / Q000473:pathology / Q000601:surgery*; D014945:Wound Healing / Q000502:physiology
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D004396:Coloring Agents; D015921:Dental Implants; D008903:Minerals; D003094:Collagen