title: Alveolar socket preservation technique: Effect of biomaterial on bone regenerative pattern.
abstract: BACKGROUND
  There is a lack of evidence in the literature on the correlation between histomorphometric findings and gene/protein expression markers for bone metabolism.
  
  
  OBJECTIVE
  Evaluation of the histological features, changes in protein expression and gene activation for specific markers of bone metabolism following application of the alveolar ridge preservation technique with magnesium-enriched hydroxyapatite (MgHA).
  
  
  METHODS
  For each patient (n=15), bone samples were harvested after tooth extraction and processed for immunohistochemical and gene expression analysis (T0). Then, all alveolar sockets were grafted with MgHA. After 4 months (T1), bone samples were harvested for histomorphometrical, immunohistochemical and gene expression analysis. Gene expression and protein expression were evaluated for: RANK, RANKL, OPG, IL-6, TNF-α.
  
  
  RESULTS
  For all markers, gene expression increased, but not significantly, from T0 to T1. The mean RANKL/OPG ratio was 1.88±1.24. Protein expression increased significantly (p<0.05) for TNF-α, IL-6, RANK and RANKL. Histomorphometrical features at T1 were not significantly related to protein expression at T0.
  
  
  CONCLUSIONS
  After ridge preservation with MgHA, markers for bone catabolism were activated. No significant correlation was found between histomorphometrical features of the regenerated tissue and protein expression at baseline.
authors.affiliation: Private Practice, Rome, Italy. Electronic address: luigicanullo@yahoo.com.
authors.forename: Luigi
authors.initials: L
authors.lastname: Canullo
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy; IRCCS Galeazzi Orthopaedic Institute, Milan, Italy.
authors.forename: Gaia
authors.initials: G
authors.lastname: Pellegrini
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Canciani
authors.affiliation: Private Practice, Morsbach, Germany; Greifswald University Hospital, Department of Prosthodontics, Gerodontology and Dental Materials, Greifswald, Germany.
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Heinemann
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy; IRCCS Galeazzi Orthopaedic Institute, Milan, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Galliera
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Dellavia
mesh_terms: D016301:Alveolar Bone Loss / Q000378:metabolism / Q000628:therapy*; D000540:Alveolar Ridge Augmentation / Q000379:methods; D001672:Biocompatible Materials / Q000627:therapeutic use; D001861:Bone Regeneration / Q000502:physiology*; D017886:Durapatite / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008274:Magnesium / Q000627:therapeutic use; D008297:Male; D008422:Materials Testing; D008875:Middle Aged; D014081:Tooth Extraction / Q000009:adverse effects*; D020390:Tooth Socket / Q000187:drug effects / Q000503:physiopathology*; D016896:Treatment Outcome
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite; D008274:Magnesium
keywords: Alveolar socket preservation; Bone regeneration; IL-6; Immunohistochemistry; Magnesium-enriched hydroxyapatite; RANK/RANKL/OPG; TNF-α