title: Evaluation of perforated demineralized dentin scaffold on bone regeneration in critical-size sheep iliac defects.
abstract: OBJECTIVE
  Regenerating critical-size bone injury is a major problem that continues to inspire the design of new graft materials. Therefore, tissue engineering has become a novel approach for targeting bone regeneration applications. Human teeth are a rich source of stem cells, matrix, trace metal ions, and growth factors. A vital tooth-derived demineralized dentin matrix is acid-insoluble and composed of cross-linked collagen with growth factors. In this study, we recycled human non-functional tooth into a unique geometric dentin scaffold, entitled perforated root-demineralized dentin matrix (PR-DDM). The aim of this study was to evaluate the feasibility of PR-DDM as the scaffold for regenerating bone in critical-size iliac defects.
  
  
  METHODS
  Artificial macro-pores (1 mm in diameter) were added to human vital wisdom tooth after removing the enamel and pulp portions. The modified tooth was demineralized in 0.34 N HNO3for 30 min and is referred to as PR-DDM scaffold. Critical-size defect (10 mm × 15 mm × 9 mm Ø) was created in the iliac crest of six adult sheep. The in vivo bone regeneration by the scaffold was evaluated by micro-CT, 3D micro-CT, and histological examination at 2 and 4 months post-implantation.
  
  
  RESULTS
  PR-DDM exhibited better bone ingrowth, especially in the artificial macro-pores. The results of micro-CT and 3D micro-CT revealed good union between scaffold and native bone. New bone formation was observed in almost all portions of PR-DDM. Higher bone volume inside the scaffold was detected at 4 months compared with 2 months. New bone ingrowth was ankylosed with PR-DDM, and both osteoinduction and osteoconduction capability of PR-DDM were confirmed histologically. The ratio of new bone formation was higher at 4 months compared with 2 months by histomorphometric analysis.
  
  
  CONCLUSIONS
  Altogether, these results demonstrated that the human tooth-derived graft material with a unique geometric structure, PR-DDM, contributed to active bone ingrowth in critical-size bone defects. This novel scaffold may have great utility in the near-future clinical application.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Health Sciences, University of Hokkaido, Hokkaido, Japan.
authors.forename: Md Arafat
authors.initials: MA
authors.lastname: Kabir
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Health Sciences, University of Hokkaido, Hokkaido, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Murata
authors.affiliation: Group of Polymer and Ceramic Materials, Industrial Research Institute, Hokkaido Research Organization, Hokkaido, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Akazawa
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Dentistry, Health Sciences, University of Hokkaido, Hokkaido, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kusano
authors.affiliation: Department of Orthopedic Surgery, Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Spine and Spinal Cord Disorders, National Hospital Organization, Hokkaido Medical Center, Sapporo, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Ito
mesh_terms: D000818:Animals; D001861:Bone Regeneration; D003804:Dentin / Q000637:transplantation*; D048091:Guided Tissue Regeneration / Q000379:methods*; D006801:Humans; D007085:Ilium / Q000293:injuries* / Q000601:surgery; D008297:Male; D012756:Sheep; D054457:Tissue Scaffolds
chemical_list: C093073:Demineralized Dentin Matrix
keywords: bone regeneration; critical defects; human dentin; scaffold