title: A randomized controlled evaluation of alveolar ridge preservation following tooth extraction using deproteinized bovine bone mineral and demineralized freeze-dried bone allograft.
abstract: BACKGROUND
  Alveolar ridge preservation could be performed immediately following tooth extraction to limit dimensional changes of alveolar process due to bone resorption. The aim of this study was to compare the clinical and histologic outcomes of socket preservation using two different graft materials; deproteinized bovine bone mineral (DBBM) and demineralized freeze-dried bone allograft (DFDBA) with absorbable collagen membrane.
  
  
  METHODS
  Twenty extraction sockets in 20 patients were randomly divided into 2 treatment groups: 10 sockets were augmented with DBBM and collagen membrane whereas 10 sockets were filled with DFDBA and covered by collagen membrane. Primary closure was achieved over extraction sockets by flap advancement. Horizontal and vertical ridge dimensional changes were assessed at baseline and after 4-6 months at the time of implant placement. For histological and histomorphometrical analysis, bone samples were harvested from the augmented sites with trephine during implant surgery. All data were analyzed using SPSS version 18 (α=0.05).
  
  
  RESULTS
  Clinical measurements revealed that average horizontal reduction was 2.3 ± 0.64 mm for DFDBA and 2.26 ± 0.51 mm for DBBM. Mean vertical ridge resorption at buccal side was 1.29 ± 0.68 mm for DFDBA and 1.1 ± 0.17 mm for DBBM. Moreover, mean vertical ridge reduction at lingual site was 0.41 ± 0.38 mm and 0.35 ± 0.34 mm for DFDBA and DBBM, respectively. No significant differences were seen between two groups in any of those clinical parameters. Histologic analysis showed statistically significant more new bone deposition for DFDBA compared to DBBM (34.49 ± 3.19 vs. 18.76 ± 3.54) (P < 0.01). Residual graft particles were identified significantly more in DBBM (12.77 ± 1.85) than DFDBA (6.06 ± 1.02).
  
  
  CONCLUSIONS
  Based on the findings of this study, both materials have positive effect on alveolar ridge preservation after tooth extraction, but there was more new bone formation and less residual graft particles in DFDBA group than in DBBM group.
authors.affiliation: Department of Periodontics, Faculty of Dentistry, Shahed University, Tehran, Iran.
authors.forename: Rokhsareh
authors.initials: R
authors.lastname: Sadeghi
authors.affiliation: Department of Periodontics, Faculty of Dentistry, Zanjan University of Medical Sciences, Zanjan, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Babaei
authors.affiliation: Department of Periodontics, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: S Asghar
authors.initials: SA
authors.lastname: Miremadi
authors.affiliation: Department of Oral and Maxillofacial Pathology, Faculty of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Fatemeh Mashadi
authors.initials: FM
authors.lastname: Abbas
keywords: Collagen; extraction; graft; material; membrane; preservation; socket