title: Variability in Particle Degradation of Four Commonly Employed Dental Bone Grafts.
abstract: BACKGROUND
  Replacement bone grafting materials are used clinically for a variety of clinical procedures to augment and replace lost or missing bone. Little information is available regarding their degradation properties.
  
  
  OBJECTIVE
  The aim of the present study was to investigate the degradation rate and modes of degradation of four commonly used bone grafting materials.
  
  
  METHODS
  A natural bone mineral (NBM) of bovine origin, NBM in combination with enamel matrix derivative (EMD), LifeNet demineralized freeze-dried bone allograft (DFDBA), and Osteotech DFDBA were analyzed for particle degradation over time in 3 mm femur defects created in female Wistar rats. At 2, 4, and 8 weeks postimplantation, femur defects were assigned to histological analysis. Hematoxylin and eosin, Safranin O, tartrate-resistant acid phosphatase (TRAP), receptor activator of nuclear factor kappa B ligand (RANKL), and matrix metalloproteinase-2 (MMP-2) staining were performed to determine the rate of particle degradation, number of osteoclasts around particles, and intensity and localization of TRAP, RANKL, and MMP-2 staining.
  
  
  RESULTS
  In the present study, NBM particles demonstrated little signs of degradation. The combination of NBM with EMD significantly increased the number of osteoclasts around NBM particles and increased expression of RANKL and MMP-2 specifically around particle surface. Only minor resorption was observed. Both DFDBA particles showed much faster degradation of particles. Interestingly, fewer osteoclasts were found on their surface when compared with NBM particles, specifically on Osteotech DFDBA particles, suggesting an alternative mode of degradation. Osteotech DFDBA particles demonstrated significantly faster degradation when compared with all other bone grafts. No obvious increase in TRAP, RANKL, or MMP2 was observed to validate this fast rate of degradation.
  
  
  CONCLUSIONS
  The results from the present study demonstrate a wide range of particle degradation between various commonly commercially available bone grafts. Further research to determine the precise mechanisms that influence particle degradation is necessary.
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Yang
authors.affiliation: School of Stomatology, Nanchang University, Nanchang, China.|School of Materials Science and Engineering, Nanchang University, Nanchang, China.
authors.forename: Liao
authors.initials: L
authors.lastname: Lan
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Miron
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Lingfei
authors.initials: L
authors.lastname: Wei
authors.affiliation: School of Materials Science and Engineering, Nanchang University, Nanchang, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.affiliation: The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.|Department of Oral Implantology, School of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000032:analysis*; D016025:Bone Transplantation / Q000379:methods*; D002417:Cattle; D005260:Female; D005612:Freeze Drying; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018786:Bone Substitutes
keywords: bone graft; guided bone regeneration; intrabony defect; periodontal regeneration