title: Imaging analysis of early DMP1 mediated dentine remineralization.
abstract: OBJECTIVE
  This study assessed the micro-morphological changes in demineralized dentine scaffold following incubation with recombinant dentine matrix protein 1 (rDMP1).
  
  
  METHODS
  Extracted human molar crowns were sectioned into 6 beams (dimensions: 0.50mm×1.70mm×6.00mm), demineralized and incubated overnight in 3 different media (n=4): rDMP1 in bovine serum albumin (BSA), BSA and distilled water. Samples were placed in a chamber with simulated physiological concentrations of calcium and phosphate ions at constant pH 7.4. Samples were immediately processed for transmission electron microscopy (TEM) and field emission-scanning electron microscopy (FE-SEM) after 1 and 2 weeks.
  
  
  RESULTS
  Analysis of the scaffold showed that decalcification process retained the majority of endogenous proteoglycans and phosphoproteins. rDMP1 treated samples promoted deposition of amorphous calcium phosphate (ACP) precursors and needle shaped hydroxyapatite crystals surrounding collagen fibrils. The BSA group presented ACP bound to collagen with no needle-like apatite crystals. Samples kept in distilled water showed no evidence of ACP and crystal apatite. Results from rDMP1 immobilized on dentine matrix suggests that the acidic protein was able to bind to collagen fibrils and control formation of amorphous calcium phosphate and its subsequent transformation into hydroxyapatite crystals after 2 weeks.
  
  
  CONCLUSIONS
  These findings suggest a possible bio-inspired strategy to promote remineralization of dentine for reparative and regenerative purposes.
authors.affiliation: Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, 801 South Paulina street, Chicago, IL 60612, USA. bedran@uic.edu
authors.forename: Ana K
authors.initials: AK
authors.lastname: Bedran-Russo
authors.forename: Sriram
authors.initials: S
authors.lastname: Ravindran
authors.forename: Anne
authors.initials: A
authors.lastname: George
mesh_terms: D000293:Adolescent; D000328:Adult; D002118:Calcium / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D003094:Collagen / Q000378:metabolism; D003461:Crystallography; D003804:Dentin / Q000648:ultrastructure*; D017886:Durapatite / Q000737:chemistry; D016326:Extracellular Matrix Proteins / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D010710:Phosphates / Q000737:chemistry; D010750:Phosphoproteins / Q000737:chemistry* / Q000648:ultrastructure; D010756:Phosphoric Acids / Q000737:chemistry; D011485:Protein Binding; D011509:Proteoglycans / Q000648:ultrastructure; D011994:Recombinant Proteins; D012709:Serum Albumin / Q000737:chemistry; D017001:Tooth Demineralization / Q000473:pathology*; D014089:Tooth Remineralization / Q000379:methods*; D014867:Water / Q000737:chemistry; D055815:Young Adult
chemical_list: D002130:Calcium Phosphates; C513309:DMP1 protein, human; D016326:Extracellular Matrix Proteins; D010710:Phosphates; D010750:Phosphoproteins; D010756:Phosphoric Acids; D011509:Proteoglycans; D011994:Recombinant Proteins; D012709:Serum Albumin; D014867:Water; D003094:Collagen; D017886:Durapatite; C020243:calcium phosphate; C030242:phosphoric acid; D002118:Calcium